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Areas of expansion in the human cortex during infancy and childhood, top, closely match areas of change in the human brain when compared to the brains of apes and monkeys. Yellow areas expanded the most, followed by orange, red, blue and light blue areas. (Credit: Washington University School of Medicine in St. Louis.)

ScienceDaily (July 13, 2010) — A study undertaken to help scientists concerned with abnormal brain development in premature babies has serendipitously revealed evolution’s imprint on the human brain.

Scientists at Washington University School of Medicine in St. Louis found that the human brain regions that grow the most during infancy and childhood are nearly identical to the brain regions with the most changes when human brains are compared to those of apes and monkeys.

Researchers report the finding in a detailed comparison of the brains of normal-term infants and healthy young adults published online in the Proceedings of the National Academy of Sciences.

Scientists conducted the study to help assess the long-term effects of premature birth on brain development. These can include increased risks of learning disabilities, attention deficits, behavioral problems and cognitive impairments.

"Pre-term births have been rising in recent years, and now 12 percent of all babies in the United States are born prematurely," says Terrie Inder, MD, PhD, professor of pediatrics. "Until now, though, we were very limited in our ability to study how premature birth affects brain development because we had so little data on what normal brain development looks like."

Among the questions Inder and her colleagues hope to answer is the extent to which the brain can adapt to developmental limitations or setbacks imposed by early birth. They are also helping to develop clinical strategies to promote such adaptations and normalize development.

The study used a technique for comparative brain anatomy called surface reconstruction pioneered by senior author David Van Essen, PhD, Edison Professor and head of the Department of Anatomy and Neurobiology. Surface reconstruction helps scientists more closely align comparable regions and structures in many different brains and has been used to create online atlases of brain structure.

First author Jason Hill, an MD/PhD student, analyzed the brain scans of 12 full-term infants and compared these to scans from 12 healthy young adults. Data from the two groups were combined into a single atlas to help scientists quantify the differences between the infant and young-adult brains.

They found that the cerebral cortex, the wrinkled area on the surface of the brain responsible for higher mental functions, grows in an uneven fashion. Every region expands as the brain matures, but one-quarter to one-third of the cortex expands approximately twice as much as other cortical areas during normal development.

"Through comparisons between humans and macaque monkeys, my lab previously showed that many of these high-growth regions are expanded in humans as a result of recent evolutionary changes that made the human brain much larger than that of any other primate," says Van Essen. "The correlation isn’t perfect, but it’s much too good to put down to chance."

The high-growth regions are areas linked to advanced mental functions such as language, reasoning, and what Van Essen calls "the abilities that make us uniquely human." He speculates that the full physical growth of these regions may be delayed somewhat to allow them to be shaped by early life experiences.

Inder notes another potential explanation for the different development rates: the limitations on brain size imposed by the need to pass through the mother’s pelvis at birth may force the brain to prioritize.

"Vision, for example, is a brain area that is important at birth so an infant can nurse and learn to recognize his or her parents," Inder says. "Other areas of the brain, less important very early in life, may be the regions that see greater growth as the child matures."

Researchers are currently conducting similar scans of premature babies at birth and years later.

"This study and the data that we’re gathering now could provide us with very powerful tools for understanding what goes wrong structurally in a wide range of childhood disorders, from the aftereffects of premature birth to conditions like autism, attention-deficit disorder or reading disabilities," Inder says.

Funding from the National Institutes of Health, the Doris Duke Foundation and the Green Fund supported this research.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Washington University School of Medicine. The original article was written by Michael C. Purdy.

Journal Reference:

1. Jason Hill, Terrie Inder, Jeffrey Neil, Donna Dierker, John Harwell, and David Van Essen. Similar patterns of cortical expansion during human development and evolution. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1001229107

Washington University School of Medicine (2010, July 13). Baby brain growth mirrors changes from apes to humans. ScienceDaily. Retrieved July 14, 2010, from http://www.sciencedaily.com­ /releases/2010/07/100712154422.htm

Note: If no author is given, the source is cited instead.

New species discovered on ocean floor

Aberdeen scientists may be closer to finding missing evolutionary link

Published: 07/07/2010, Press and Journal

SCIENTISTS from Aberdeen have uncovered more than 10 new species of deep-sea life on the Atlantic Ocean floor – and may be closer to finding the missing evolutionary link between backboned and invertebrate animals.

They found abundant numbers of species thought to have been rare, and huge differences in habitats just a few miles apart.

Professor Monty Priede, of Aberdeen University’s Ocean-lab, compared some of the habitats he and his team encountered on the six-week trip to “a scene from Alice Through the Looking Glass”.

And he said the discoveries they made along the Mid-Atlantic Ridge between Iceland and the Azores had revolutionised scientific thinking about life in the ocean.    

In more than 300 hours of diving missions, they sent the UK’s deepest-diving remotely operated vehicle (ROV) nearly two nautical miles down to survey the giant mountain range which divides the Atlantic into east and west.

They focused on two areas – the cold depths north of the Gulf Stream and the warmer waters to the south.

Prof Priede said: “We were surprised at how different the animals were on either side of the ridge, which is just tens of miles apart.

“The terrain looked the same, mirror images of each other, but that is where the similarity ended.

“It seemed like we were in a scene from Alice Through the Looking Glass.”

Sea urchins dominated the flat plains of the north-east Atlantic, while the cliffs were rich with colourful sponges and corals. In the north-west the dull, grey, rock cliffs supported much less life, but enteropneust acorn worms on the plains more than made up for any disappointment.

Only a few specimens from the Pacific Ocean were previously known to science.

And while these creatures lacked eyes, sense organs or brains, their primitive bodies and basic swimming behav-iour were one of the most exciting finds of the trip.

Prof Priede said: “These worms are members of a little-known group of animals close to the missing link in evolution. By the end of the expedition three species were discovered, each with a different colour – pink, purple and white – with distinctly different shapes.”

Sea cucumbers, normally found crawling over the ocean floor, also proved a revelation, clinging to the steep faces of the mountain range and proving themselves very able and fast swimmers.

Prof Priede added: “This expedition has revolutionised our thinking about deep-sea life in the Atlantic Ocean.

“Using new technology and precise navigation we can access these regions and discover things we never suspected existed.”

The scientists on board the RSS James Cook were completing the last leg of MAR-ECO – part of the Census of Marine Life research programme along the Mid-Atlantic Ridge.

Aberdeen University is leading the UK contribution to the project, which involves scientists from 16 nations.

The findings reject allopatric speciation in a case study from a system thought to exemplify it, and suggest the potential importance of speciation due to differences in ecological conditions (ecological speciation).

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Precursor island regions, lineages, transects, and ecotone on Martinique. (Credit: Thorpe RS, Surget-Groba Y, Johansson H. Genetic Tests for Ecological and Allopatric Speciation in Anoles on an Island Archipelago. PLoS Genetics, 2010; 6(4): e1000929 DOI: 10.1371/journal.pgen.1000929)

ScienceDaily (May 1, 2010) — A genetic study of island lizards shows that even those that have been geographically isolated for many millions of years have not evolved into separate species as predicted by conventional evolutionary theory.

Professor Roger Thorpe and colleagues Yann Surget-Groba and Helena Johansson, at Bangor University, UK, reveal their findings April 29 in the open-access journal PLoS Genetics.

Since Darwin’s study of the Galapagos Islands, archipelagos have played a central role in understanding how new species evolve from existing ones (speciation). Islands epitomize allopatric speciation, where geographic isolation causes individuals of an original species to accumulate sufficient genetic differences to prevent them breeding with each other when they are reunited.

Current day Martinique in the Lesser Antilles is composed of several ancient islands that have only recently coalesced into a single entity. The phylogeny and geology show that these ancient islands have had their own tree lizard (anole) species for about six to eight million years. 

Capitalizing on the islands’ meeting, the authors genetically tested the lizards for reproductive isolation from one another. In using selectively neutral genetic markers, the authors saw that these anoles are freely exchanging genes and therefore not behaving as separate species. Indeed, there is more genetic isolation between conspecifics from different habitats than between those lizards originating from separate ancient islands.

The findings reject allopatric speciation in a case study from a system thought to exemplify it, and suggest the potential importance of speciation due to differences in ecological conditions (ecological speciation). “The next step is to identify the genes controlling the traits influencing the process of speciation,” said Roger Thorpe.

Adapted from materials provided by Public Library of Science, via EurekAlert!, a service of AAAS.

1. Thorpe RS, Surget-Groba Y, Johansson H. Genetic Tests for Ecological and Allopatric Speciation in Anoles on an Island Archipelago. PLoS Genetics, 2010; 6(4): e1000929 DOI: 10.1371/journal.pgen.1000929

This page lists the most accessible literature on evolution including the critics of evolution. The emphasis is on recent, affordable books for non-specialists written by specialists.

by Gert Korthof (updated 23 Apr 2010)

http://home.planet.nl/~gkorthof/korthof.htm

Extensions & alternative evolutionary theories
Evo-Devo
Non-religious Anti-Darwinism + Anti-Evolution
Religious criticism:
Creationism / Intelligent Design
Fine Tuning
Theistic Evolution
Buddhism & Hinduism
Orthodox neo-Darwinism
textbooks Evolutionary Biology
introductions
Anti-Creationism/ID
Origin of life & Astrobiology
Ecology & Earth System Science
History of Darwinism
Bibliographies, anthologies, encyclopedias
Human evolution (general)
Psychology, Behaviour & Brain
Sex & evolution
Genetics & genomics
Medicine & evolution
Economics & evolution
Politics, ethics & evolution
Theoretical & mathematical biology
Philosophy & evolution
History & evolution
Engineering & evolution
Evolution & Literature

philosophy of science
books suggested by readers
Scientific controversies
Nederlandse literatuur

This page lists the most accessible literature on evolution including the critics of evolution. The emphasis is on recent, affordable books for non-specialists written by specialists. This page shortly characterises noteworthy books and gives links to book reviews in Nature, Science, etc (19). Furthermore, I have written detailed reviews of many books which are on separate pages of the site Was Darwin Wrong? (now called: ‘The Third Evolutionary Synthesis’). Those reviews are listed in a handy table on the index page. I have subdivided the literature in categories and subcategories (see directory structure above). The goal of this site contains also information about myself. If the reader feels I omitted books that belong on this introduction page, please drop me a note. They are included on this page or suggestions by readers.

Extensions, revisions & alternative evolutionary theories
top

This is a category of scientific, non-religious critics of Darwinism. Here we find scientists who do accept evolution (common descent), but aren’t happy with parts of the neo-Darwinist explanation of evolution (mainly the mechanism of evolution: natural selection). 

Against natural selection
One of the earliest critics of the sufficiency of natural selection as an explanation of form in biology was D’Arcy Thompson On Growth and Form (1917). He was not a creationist: he granted that natural selection could weed out the unfit, but doubted the power of natural selection to explain why life took one form and not another. He preferred to explain the forms of organisms by mechanical and mathematical principles (13). In his spirit are books by Philip Ball and Brian Goodwin. About the same time geneticist and Nobelprize winner Thomas Hunt Morgan expressed similar doubts in Evolution and Adaptation (1903) (24). The criticism of population geneticist Motoo Kimura was that all-powerful natural selection was not powerful enough to eliminate all mutations at the DNA level. He called these mutations neutral mutations, because they are not affected by selection, positive or negative. He was right. An alternative explanation for the peacock’s tail turned into a new principle: The Handicap Principle. A missing piece of Darwin’s puzzle by A & A Zahavi (1999); initially unanimously rejected, currently largely accepted by mainstream science. Gabriel Dover claims there is a third force in evolution.
An example of a palaeontologist who accepts evolution, but rejects the claim that palaeontology can determine missing links with certainty, is: Henry Gee. Although cladism is now widely accepted, I hesitate to place Gee in the category ‘Orthodox Neo-Darwinism’ because of his criticism of orthodox palaeontology. The eminent but unorthodox astronomer sir Fred Hoyle wrote an attack on the fundamentals of neo-Darwinism using high level mathematics: Mathematics of Evolution. Years ago Hoyle introduced the much quoted analogy that the chance of life originating out of raw materials would be equal to the chance that a Boeing-747 resulted from a hurricane going over a junkyard. Hoyle believes life came from space (panspermia). The immunologist Edward J. Steele wrote what could be called the textbook of ‘neo-Lamarckism’. He explains in molecular terms how acquired characteristics of the immune system can be inherited in: Lamarck’s Signature: How Retrogenes Are Changing Darwin’s Natural Selection Paradigm. The embryologist Brian Goodwin has interesting ideas about scientific alternatives for Darwinism. A critique of selectionism and the proposal of an alternate theory of emergent evolution is: Biological Emergences. Evolution by Natural Experiment by Robert G. B. Reid (2007) (info), emeritus Professor of Biology and author of ‘Evolutionary Theory: The Unfinished Synthesis‘ (1985). Palaeontologist Niles Eldredge argues against the reductionism of the ‘ultra-Darwinist’. Hubert Yockey is an expert in the information content of genomes, DNA and proteins. Yockey believes that there is too much information in the simplest organisms to have originated by chance, but unlike "intelligent design theorists", he does not infer design or a designer (at least in his book). He has no alternative theory.
    Palaeontologist Stephen Jay Gould is known by the public from his column in Natural History and the New York Review of Books and as a defender of evolution (that includes rejection of creationism). It is not so well known that he is also a critic of orthodox neo-Darwinism. Two criticisms are: not everything is adaptation, and evolution is not gradual but punctuated. This and much, much more in his voluminous The Structure of Evolutionary Theory (2002).
In The tinkerer’s accomplice: how design emerges from life itself J. Scott Turner (2007) argues that "organisms are designed not so much because natural selection of particular genes has made them that way, but because agents of homeostasis build them that way" (Review).
Evolutionary biologist John Reiss (2009) Not by Design; Retiring Darwin’s Watchmaker argues that we can’t infer the past action of selection from the present adaptedness (apparent design) of organisms (25).
Jerry Fodor and Piattelli-Palmarini (2010) wrote a critique of the theory of natural selection: What Darwin Got Wrong (Reviews: Michael Ruse, Philip Kitcher, (continued), Philip Ball, Mary Midgley, interview, Nature).

Source: http://home.planet.nl/~gkorthof/korthof.htm

NASA lab accused of crackdown on intelligent design

Complaint alleges harassment, secret investigation, gag order

“When it comes to intelligent design, private and government-run agencies are suppressing free speech.”

By Bob Unruh, April 15, 2010
© 2010 WorldNetDaily

A complaint has been filed against NASA’s Jet Propulsion Lab, which sent Galileo to Jupiter and dispatched a ship named Dawn to orbit asteroids Vesta and Ceres, claiming managers there discriminated against and demoted a key project worker because he shared intelligent design videos with co-workers.

The case has been filed by David Coppedge, an information technology specialist and systems administrator on the lab’s Cassini mission to Saturn, which has been described as the most ambitious interplanetary exploration ever launched.

“For the offense of offering videos to colleagues, Coppedge faced harassment, an investigation cloaked in secrecy, and a virtual gag order on his discussion of intelligent design,” said attorney Casey Luskin of Discovery Institute’s Center for Science and Culture.

Luskin serves as a consultant to the Coppedge lawsuit, which is being handled by Los Angeles First Amendment attorney William J. Becker, Jr., of The Becker Law Firm, and includes allegations of free speech violations and wrongful demotion.

“Coppedge was punished even though supervisors admitted never receiving a single complaint regarding his conversations about intelligent design prior to their investigation, and even though other employees were allowed to express diverse ideological opinions, including attacking intelligent design,” Luskin said. 

The complaint was filed in California Superior Court. But officials at the JPL today told WND they had not yet seen the court filing and could not comment.

The action explains that a division of the California Institute of Technology, JPL operates under a contract with NASA.

David Coppedge

Coppedge was a “Team Lead” Systems Administrator on the Cassini mission until JPL demoted him for allegedly “pushing religion” by loaning interested co-workers DVDs supportive of intelligent design.

Coppedge is suing JPL and Caltech for religion discrimination and harassment, retaliation, violation of his religious rights and wrongful demotion.

“Intelligent design is not religion, and nothing in the DVDs that Coppedge shared deals with religion,” said Luskin. “Even so, it’s unlawful for an employer to discriminate against an employee based on what they deem is religion.”

Among the coming JPL projects is Aquarius, which is to offer the first-ever global maps of salt concentrations in the ocean surface needed to understand heat transport and storage in the ocean.

Its Deep Space 1 left Earth in 1998 and tested an ion engine that could power future solar system explorers.

But the case alleges Coppedge’s supervisors demoted and humiliated him for advancing ideas that superiors labeled “unwelcome” and “disruptive.”

The situation reach a boiling point in 2009 when a supervisor angrily harassed Coppedge, claiming “intelligent design is religion” and that Coppedge was “pushing religion.”

Coppedge’s complaint about that harassment resulted in a retaliatory investigation and “severe limitations” on Coppedge’s free speech rights, the case explains.

The actions against him continued, even though supervisors eventually admitted they had no complaints about him, and other employees were allowed to discuss whatever topics they chose, the case explains.

The complaint said, “Intelligent design offers scientific evidence that life’s development is best explained as reflecting the design of an intelligent cause, citing mainstream research in biology, cosmology, and paleontology.”

The DVDs included: “Unlocking the Mystery of Life,” and “The Privileged Planet.”

The Discovery Institute notes this is just the latest in a series of disputes involving the concept of intelligent design and how it conflicts with belief in evolution.

Previously, the California Science Center in Los Angeles, a state agency, was sued following its “discriminatory cancellation” of a contract to screen an intelligent design film.

At at Iowa State in 2006, supervisors denied tenure to and forced out a distinguished astrophysicist for co-authoring a book on intelligent-design in cosmology.

Earlier, in 2005, supervisors at the Smithsonian investigated, harassed and demoted an evolutionary biologist for editing a pro-intelligent design article in a peer-reviewed technical journal.

And in University of Idaho in 2005, the university’s president banned faculty on campus from teaching against evolutionary orthodoxy.

“Anyone who thinks that today’s culture of science allows an open discussion of evolution is sorely mistaken,” said John G. West, associate director of the Center for Science and Culture. “When it comes to intelligent design, private and government-run agencies are suppressing free speech.”

MIT Press, April 2010

Edited by Massimo Pigliucci and Gerd B. Müller

In the six decades since the publication of Julian Huxley’s Evolution: The Modern Synthesis, spectacular empirical advances in the biological sciences have been accompanied by equally significant developments within the core theoretical framework of the discipline. As a result, evolutionary theory today includes concepts and even entire new fields that were not part of the foundational structure of the Modern Synthesis. In this volume, sixteen leading evolutionary biologists and philosophers of science survey the conceptual changes that have emerged since Huxley’s landmark publication, not only in such traditional domains of evolutionary biology as quantitative genetics and paleontology but also in such new fields of research as genomics and EvoDevo.

Most of the contributors to Evolution—The Extended Synthesis accept many of the tenets of the classical framework but want to relax some of its assumptions and introduce significant conceptual augmentations of the basic Modern Synthesis structure—just as the architects of the Modern Synthesis themselves expanded and modulated previous versions of Darwinism. This continuing revision of a theoretical edifice the foundations of which were laid in the middle of the nineteenth century—the reexamination of old ideas, proposals of new ones, and the synthesis of the most suitable—shows us how science works, and how scientists have painstakingly built a solid set of explanations for what Darwin called the "grandeur" of life.

Contributors: John Beatty, Werner Callebaut, Jeremy Draghi, Chrisantha Fernando, Sergey Gavrilets, John C. Gerhart, Eva Jablonka, David Jablonski, Marc W. Kirschner, Marion J. Lamb, Alan C. Love, Gerd B. Müller, Stuart A. Newman, John Odling-Smee, Massimo Pigliucci, Michael Purugganan, Eörs Szathmáry, Günter P. Wagner, David Sloan Wilson, Gregory A. Wray
About the Editors
Massimo Pigliucci is Professor of Philosophy at the City University of New York.
Gerd B. Müller is Professor of Theoretical Biology at the University of Vienna and Chairman of the Konrad Lorenz Institute for Evolution and Cognition Research. He is a coeditor of Origination of Organismal Form (MIT Press, 2003) and Modeling Biology (MIT Press, 2007).

Endorsements

"The essays in this volume provide ample food for thought, and from all the major food groups! The Modern Synthesis in evolutionary theory, and what lies beyond, are assessed here from multiple angles. This book will greatly interest evolutionary biologists and philosophers of evolutionary biology alike."
—Elliott Sober, Hans Reichenbach Professor and William F. Vilas Research Professor, Department of Philosophy, University of Wisconsin-Madison

"The twenty-first century will likely be the century of biology, just as the twentieth century was the century of physics. The central, organizing theory of biology is—and will remain—the theory of evolution. If you want to know how the theory of evolution will likely expand and be configured in the twenty-first century, reading Evolution – the Extended Synthesis is a good way to start.”
—Francisco J. Ayala, Donald Bren Professor of Biological Sciences, University of California, Irvine and author of Human Evolution: Trails from the Past

What if Darwin’s theory of natural selection is inaccurate? What if the way you live now affects the life expectancy of your descendants? Evolutionary thinking is having a revolution . . .

Oliver Burkeman, The Guardian, Friday 19 March 2010

The story, still sometimes repeated in creationist circles, goes like this: it is the 1960s, at Nasa’s Goddard Space Flight Centre in Maryland, and a team of astronomers is using cutting-edge computers to recreate the orbits of the planets, thousands of years in the past. Suddenly, an error message flashes up. There’s a problem: way back in history, one whole day appears to be missing.

The scientists are baffled, until a Christian member of the team dimly recalls something and rushes to fetch a Bible. He thumbs through it until he reaches the Book of Joshua, chapter 10, in which Joshua asks God to stop the world for . . . "about a full day!" Uproar in the computer lab. The astronomers have happened upon proof that God controls the universe on a day-to-day basis, that the Bible is literally true, and that by extension the "myth" of creation is, in fact, a reality. Darwin was wrong – according to another creationist rumour, he’d recanted on his deathbed, anyway – and here, at last, is scientific evidence!

Inevitably, those of us who aren’t professional scientists have to take a lot of science on trust. And one of the things that makes it so easy to trust the standard view of evolution, in particular, is amply illustrated by the legend of the Nasa astronomers: the doubters are so deluded or dishonest that one needn’t waste time with them. Unfortunately, that also makes it embarrassingly awkward to ask a question that seems, in the light of recent studies and several popular books, to be growing ever more pertinent. What if Darwin’s theory of evolution – or, at least, Darwin’s theory of evolution as most of us learned it at school and believe we understand it – is, in crucial respects, not entirely accurate?

Such talk, naturally, is liable to drive evolutionary biologists into a rage, or, in the case of Richard Dawkins, into even more of a rage than usual. They have a point: nobody wants to provide ammunition to the proponents of creationism or "intelligent design", and it’s true that few of the studies now coming to public prominence are all that revolutionary to the experts. But in the culture at large, we may be on the brink of a major shift in perspective, with enormous implications for how most of us think about how life came to be the way it is. As the science writer David Shenk puts it in his new book, The Genius in All of Us, "This is big, big stuff – perhaps the most important [discoveries] in the science of heredity since the gene."

Take, to begin with, the Swedish chickens. Three years ago, researchers led by a professor at the university of Linköping in Sweden created a henhouse that was specially designed to make its chicken occupants feel stressed. The lighting was manipulated to make the rhythms of night and day unpredictable, so the chickens lost track of when to eat or roost. Unsurprisingly, perhaps, they showed a significant decrease in their ability to learn how to find food hidden in a maze.

The surprising part is what happened next: the chickens were moved back to a non-stressful environment, where they conceived and hatched chicks who were raised without stress – and yet these chicks, too, demonstrated unexpectedly poor skills at finding food in a maze. They appeared to have inherited a problem that had been induced in their mothers through the environment. Further research established that the inherited change had altered the chicks’ "gene expression" – the way certain genes are turned "on" or "off", bestowing any given animal with specific traits. The stress had affected the mother hens on a genetic level, and they had passed it on to their offspring.

The Swedish chicken study was one of several recent breakthroughs in the youthful field of epigenetics, which primarily studies the epigenome, the protective package of proteins around which genetic material – strands of DNA – is wrapped. The epigenome plays a crucial role in determining which genes actually express themselves in a creature’s traits: in effect, it switches certain genes on or off, or turns them up or down in intensity. It isn’t news that the environment can alter the epigenome; what’s news is that those changes can be inherited. And this doesn’t, of course, apply only to chickens: some of the most striking findings come from research involving humans.

One study, again from Sweden, looked at lifespans in Norrbotten, the country’s northernmost province, where harvests are usually sparse but occasionally overflowing, meaning that, historically, children sometimes grew up with wildly varying food intake from one year to the next. A single period of extreme overeating in the midst of the usual short supply, researchers found, could cause a man’s grandsons to die an average of 32 years earlier than if his childhood food intake had been steadier. Your own eating patterns, this implies, may affect your grandchildren’s lifespans, years before your grandchildren – or even your children – are a twinkle in anybody’s eye.

It might not be immediately obvious why this has such profound implications for evolution. In the way it’s generally understood, the whole point of natural selection – the so-called "modern synthesis" of Darwin’s theories with subsequent discoveries about genes – is its beautiful, breathtaking, devastating simplicity. In each generation, genes undergo random mutations, making offspring subtly different from their parents; those mutations that enhance an organism’s abilities to thrive and reproduce in its own particular environment will tend to spread through populations, while those that make successful breeding less likely will eventually peter out.

As years of bestselling books by Dawkins, Daniel Dennett and others have seeped into the culture, we’ve come to understand that the awesome power of natural selection – frequently referred to as the best idea in the history of science – lies in the sheer elegance of the way such simple principles have generated the unbelievable complexities of life. From two elementary notions – random mutation, and the filtering power of the environment – have emerged, over millennia, such marvels as eyes, the wings of birds and the human brain.

Yet epigenetics suggests this isn’t the whole story. If what happens to you during your lifetime – living in a stress-inducing henhouse, say, or overeating in northern Sweden – can affect how your genes express themselves in future generations, the absolutely simple version of natural selection begins to look questionable. Rather than genes simply "offering up" a random smorgasbord of traits in each new generation, which then either prove suited or unsuited to the environment, it seems that the environment plays a role in creating those traits in future generations, if only in a short-term and reversible way. You begin to feel slightly sorry for the much-mocked pre-Darwinian zoologist Jean-Baptiste Lamarck, whose own version of evolution held, most famously, that giraffes have long necks because their ancestors were "obliged to browse on the leaves of trees and to make constant efforts to reach them". As a matter of natural history, he probably wasn’t right about how giraffes’ necks came to be so long. But Lamarck was scorned for a much more general apparent mistake: the idea that lifestyle might be able to influence heredity. "Today," notes David Shenk, "any high school student knows that genes are passed on unchanged from parent to child, and to the next generation and the next. Lifestyle cannot alter heredity. Except now it turns out that it can . . ."

Epigenetics is the most vivid reason why the popular understanding of evolution might need revising, but it’s not the only one. We’ve learned that huge proportions of the human genome consist of viruses, or virus-like materials, raising the notion that they got there through infection – meaning that natural selection acts not just on random mutations, but on new stuff that’s introduced from elsewhere. Relatedly, there is growing evidence, at the level of microbes, of genes being transferred not just vertically, from ancestors to parents to offspring, but also horizontally, between organisms. The researchers Carl Woese and Nigel Goldenfield conclude that, on average, a bacterium may have obtained 10% of its genes from other organisms in its environment.

To an outsider, this is mind-blowing: since most of the history of life on earth has been the history of micro-organisms, the evidence for horizontal transfer suggests that a mainly Darwinian account of evolution may be only the latest version, applicable to the most recent, much more complex forms of life. Perhaps, before that, most evolution was based on horizontal exchange. Which gives rise to a compelling philosophical puzzle: if a genome is what defines an organism, yet those organisms can swap genes freely, what does it even mean to draw a clear line between one organism and another? "It’s natural to wonder," Goldenfield told New Scientist recently, "if the very concept of an organism in isolation is still valid at this level." In natural selection, we all know, the fittest win out over their rivals. But what if you can’t establish clear boundaries between rivals in the first place?

It is a decade since the biologist Randy Thornhill and the anthropologist Craig Palmer published The Natural History of Rape. In the book, they made an argument that – however obnoxious at first glance – seemed, to many, to follow straightforwardly from the logic of natural selection. Evolution tells us that the traits that flourish down the generations are the ones that help organisms reproduce. Evolutionary psychology argues that there’s no reason to exclude psychological traits. And since rape is indeed a trait that occurs all too frequently in human society, it follows that a desire to commit rape must be adaptive. There must be a genetic basis for it – a "rape gene", in the words of some media stories following the book’s publication – because, in prehistoric times, those men who possessed the tendency would reproduce more successfully than those who didn’t. Therefore, the authors concluded, rape was – to use a loaded term that has been getting Darwinians in trouble since Darwin – "natural".

Understandably, the book was hugely controversial. But by the time it was published, there was nothing all that radical about the idea that natural selection might be able to illuminate any and every aspect of human behaviour. Evolutionary psychology, in the hands of various practitioners, sought to explain why militarism is so prevalent in human societies, or why men tend to dominate women in so many hierarchical organisations. If the field seems less politically charged these days, that is only because it has permeated our consciousness so deeply that it has become less questioned.

For much of the late Noughties, a week never seemed to pass without one new book or news story attributing some facet of modern-day life to the evolutionary past: men were more prone to sexual jealousy than women because a woman who conceives becomes unavailable for imminent future acts of reproduction; men preferred women with waist-to-hip ratios of 0.7 because of natural selection. It explained music and art and why we reward senior executives with top-floor corner offices (because we evolved to want a clear view of our enemies approaching across the savannah). Leftwing and feminist critics did frequently misinterpret evolutionary psychology, imagining that when scholars described some trait as adaptive, they meant it was morally justifiable. But that was how many such findings – often better described as speculations – came to be believed. We’re not exactly saying it’s right for, say, men to sleep around, evolutionary psychologists would observe with a knowing sigh, but . . . well, good luck trying to change millennia of evolved behaviour.

Far more than biologists, evolutionary psychologists bought in to the ultra-simple version of natural selection, and so they stand to lose far more from advances in our understanding of what’s really been going on. They were always prone to telling "just-so stories" – spinning plausible tales about why some trait might be adaptive, instead of demonstrating that it was – and numerous recent studies have begun to chip away at what evidence there was. (That waist-to-hip ratio finding, for example, doesn’t seem to hold up in the face of international and historical research.) And now, if epigenetics and other developments are coming to suggest that environment can alter heredity, the very terms of the debate – of nature versus nurture – suddenly become shaky. It’s not even a matter of settling on a compromise, a "mixture" of nature and nurture. Rather, the concepts of "nature" and "nurture" seem to be growing meaningless. What does "nature" even mean if you can nurture the nature of your descendants?

This is one central argument of Shenk’s new book, subheaded Why Everything You’ve Been Told About Genetics, Talent and IQ is Wrong. All our popular notions about talent and "genetic gifts", he points out, start to collapse if the eating habits of Tiger Woods’s ancestors, for example, might have played a role in Woods’s golfing abilities. (Woods always crops up in discussions on the origins of genius; more recently, he has started cropping up in evolutionary psychology discussions about whether promiscuity is inevitable.)

"What all this evidence shows is that we need a much more subtle and nuanced understanding of Darwinism and natural selection," Shenk says. "I think that’s inevitably going to happen among scientists. The question is how much nuance will carry over into the public sphere . . . it’s really funny how difficult it is to have this conversation, even with a lot of people who understand the science. We’re stuck with a pretty limited way of viewing all this, and I think part of that comes from the terms" – such as nature and nurture – "that we have."

Among the arsenal of studies at Shenk’s disposal is one published last year in the Journal of Neuroscience, involving mice bred to possess genetically inherited memory problems. As small recompense for having been bred to be scatterbrained, they were kept in an environment full of stimulating mouse fun: plenty of toys, exercise and attention. Key aspects of their memory skills were shown to improve, and crucially so did those of their offspring, even though the offspring had never experienced the stimulating environment, even as foetuses.

"If a geneticist had suggested as recently as the 1990s that a 12-year-old kid could improve the intellectual nimbleness of his or her future children by studying harder now," writes Shenk, "that scientist would have been laughed right out of the hall." Not so now.

And then there is Jerry Fodor, the American philosopher. I started reading What Darwin Got Wrong, the new book he has co-authored with the cognitive scientist Massimo Piattelli-Palmarini, one morning, along with that day’s first coffee. A few pages later, as the coffee kicked in, I grasped with astonishment what Fodor had done. He hadn’t just identified evidence that natural selection was more complicated than previously thought – he’d uncovered a glaring flaw in the whole notion! Natural selection, he explains, simply "cannot be the primary engine of evolution". I got up and refilled my cup. But by the time I returned, his argument had slipped from my grasp. Suddenly, he seemed obviously wrong, tied up in philosophical knots of his own creation. I alternated between these two convictions. Was Fodor’s critique so devastatingly correct that his critics – Dawkins, Dennett, the Cambridge philosopher Simon Blackburn, and many others – simply couldn’t see it? Had he actually managed to . . . but then it slipped away again, vanishing into mental fog.

I called Fodor and asked him to explain his point in language an infant school pupil could understand. "Can’t be done," he shot back. "These issues really are complicated. If we’re right that Darwin and Darwinists have missed the point we’ve been making for 150 years, that’s not because it’s a simple point and Darwin was stupid. It’s a really complicated issue."

Fodor’s objection is a distant cousin of one that rears its head every few years: doesn’t "survival of the fittest" just mean "survival of those that survive", since the only criterion of fitness is that a creature does, indeed, survive and reproduce? The American rightwing noisemaker Ann Coulter makes the point in her 2006 pro-creationist tirade Godless: The Church of American Liberalism. "Through the process of natural selection, the ‘fittest’ survive, [but] who are the ‘fittest’? The ones who survive!" she sneers. "Why, look – it happens every time! The ‘survival of the fittest’ would be a joke if it weren’t part of the belief system of a fanatical cult infesting the Scientific Community."

This argument, perhaps uniquely among all arguments ever made by Coulter, feels persuasive, not least because it is a reasonable criticism of some pop-Darwinism. In fact, though, it’s entirely possible for scientists to measure fitness using criteria other than survival, and thus to avoid circular logic. For example, you might hypothesise that speed is a helpful thing to have if you’re an antelope, then hypothesise the kind of leg structure you’d want to have, as an antelope, in order to run fast; then you’d examine antelopes to see if they do indeed have something approximating this kind of leg structure, and you’d examine the fossil record, to see if other kinds of leg died out.

Fodor’s point is more complex than this, although it’s also possible that it is not really a point at all: several reviews of the book by professional evolutionary theorists and philosophers have concluded that it is, indeed, nonsense. As far as I can make out, it can be summarised in three steps. Step one: Fodor notes – undeniably correctly – that not every trait a creature possesses is necessarily adaptive. Some just come along for the ride: for example, genes that express as tameness in domesticated foxes and dogs also seem to express as floppy ears, for no evident reason. Other traits are, as logicians say, "coextensive": a polar bear, for example, has the trait of "whiteness" and also the trait of "being the same colour as its environment". (Yes, that’s a brain-stretching, possibly insanity-inducing statement. Take a deep breath.) Step two: natural selection, according to its theorists, is a force that "selects for" certain traits. (Floppy ears appear to serve no purpose, so while they may have been "selected", as a matter of fact, they weren’t "selected for". And polar bears, we’d surely all agree, were "selected for" being the same colour as their environment, not for being white per se: being white is no use as camouflage if snow is, say, orange.)

Step three is Fodor’s coup de grace: how, he says, can that possibly be? The whole point of Darwinian evolution is that it has no mind, no intelligence. But to "select for" certain traits – as opposed to just "selecting" them by not having them die out – wouldn’t natural selection have to have some kind of mind? It might be obvious to you that being the same colour as your environment is more important than being white, if you’re a polar bear, but that’s because you just ran a thought-experiment about a hypothetical situation involving orange snow. Evolution can’t run thought experiments, because it can’t think. "Darwin has a theory that centrally turns on the notion of ‘selection-for’," says Fodor. "And yet he can’t give an account – nobody could give an account – of how natural selection could distinguish between correlated traits. He waffles."

Those of us baffled by this argument can take solace in the fact that we’re not alone. The general response to Fodor among evolutionary thinkers has been a mixture of derision and awkwardness, as if one of their previously esteemed colleagues had entered the senior common room naked. Says Dennett, via email: "Jerry Fodor’s book is a stunning demonstration of how abhorrence of an idea (Jerry’s visceral dislike of evolutionary thinking) can derange an otherwise clever thinker . . . a responsible academic is supposed to be able to control irrational impulses, [but] Fodor has simply collapsed in the face of his dread and composed some dreadfully bad arguments." What Darwin Got Wrong, Dennett concludes, is "a book that so transparently misconstrues its target that it would be laughable were it not such dangerous mischief".

It would be jawdroppingly surprising, to say the least, were Fodor to be right. A safer, if mealy-mouthed, conclusion to draw is that his work acts as an important warning to those of us who think we understand natural selection. It’s probably not a bankrupt concept, as Fodor claims. But nor should laypeople assume that it’s self-evidently simple and exhaustively true.

The irony in all this is that Darwin himself never claimed that it was. He went to his deathbed protesting that he’d been misinterpreted: there was no reason, he said, to assume that natural selection was the only imaginable mechanism of evolution. Darwin, writing before the discovery of DNA, knew very well that his work heralded the beginning of a journey to understand the origins and development of life. All we may be discovering now is that we remain closer to the beginning of that journey than we’ve come to think.

Further reading
• From Time magazine, an excellent piece on epigenetics: http://bit.ly/5Kyj5q
• The Genius in All of Us: Why Everything You’ve Been Told about Genetics, Talent and IQ is Wrong, by David Shenk, is published by Doubleday. What Darwin Got Wrong by Jerry Fodor and Massimo Piattelli-Palmarini is published by Profile, price £20
• For more on "horizontal evolution" see New Scientist: http://bit.ly/4zzAsr
• Also from New Scientist, more on the role of viruses in evolution: http://bit.ly/bD4NLC

guardian.co.uk © Guardian News and Media Limited 2010

Self-organization and complex adaptive systems

Interview: Stuart Kauffman

The becoming of the universe — because we’re part of it — is only partially describable by natural law. In its place is a huge creativity. I want to say that God is the natural creativity in the universe.

Release Date: 03-17-2010, University of Vermont

Author: Joshua E. Brown¹
Email: Joshua.E.Brown@uvm.edu²
Phone: 802/656-3039 Fax: (802) 656-3203

Stuart Kauffman is famous for arguing that biology must look beyond Darwin. From molecules to ecosystems, he sees self-organization as the twin to natural selection in giving order to living systems. He’s joined the UVM faculty to continue making his case — and he’ll be in residence this fall, “eager for conversation across disciplines,” he says. (Photo: Joshua Brown)

In the early 1980′s, Stuart Kauffman was a tenured professor of biochemistry and biophysics at the University of Pennsylvania — but he left his ivied job to go to the deserts of New Mexico. “I was lucky enough to be at the Santa Fe Institute near the beginning and fell in love with complex adaptive systems,” he says, “but nobody knew exactly what that meant!”

A decade there, at the world-leading think-tank for complex systems — including five years as a MacArthur “genius” fellow — brought Kauffman closer to an answer than perhaps any scientist on the planet. “The combination of confusion and passion drove creativity,” he says.

There, and later at the University of Calgary, he published research on a breathtaking range of topics from the origin of life, to gene regulatory networks, to molecular evolution, to so-called fitness landscapes in evolutionary biology. A medical doctor by training, his books span from the technical Origins of Order: Self-Organization and Selection in Evolution to his recent exploration of the links between religion and science, Reinventing the Sacred.  

Kauffman will begin a three-year residency at UVM in the fall, with a joint appointment in the College of Medicine and the College of Engineering and Mathematical Sciences. He will be UVM’s first Macmillian Scholar-in-Residence, working on campus each fall semester.

“There were about 30 of us at Santa Fe who grew the field — hoping there would be others,” he says. “And now there are, here in Vermont, twenty years later. UVM has a terrific complexity group — and a terrific opportunity to lead.”

UVM Today spoke with Kauffman at the annual Vermont EPSCoR meeting in downtown Burlington where he was giving the keynote address; we wanted to learn how he sees the world and his new post at the University of Vermont.

UVM Today: What do you hope to accomplish at UVM?

Stuart Kauffman: I’d like to play a friendly catalytic role. It’s what, at 70, I really want to do.

Mostly, I’d like to foster the sciences of complexity on campus, but I think of complexity in a very broad sense. It reaches out and touches the humanities and the arts and engineering and biology and philosophy. I’ll look forward to talking to the people in the religion department. I taught at Harvard Divinity School last spring. I talked to philosophers yesterday. I am studying philosophy of mind right now. I’m blogging on NPR now and look forward to carrying on this conversation at UVM.

I want to speak about the sciences of complexity and where the frontiers of complexity are today. I know complexity really well; I’ve been doing it since I was 24.

And what is complexity?

For the first time in my life I’m distinguishing “familiar complexity” and, well, something else! There is stranger stuff that we are barely glimpsing. That is the frontier.

First though, the reason why “normal” or “familiar” complexity has emerged in the last twenty-eight years is the computer. A computer allows us to look at a system with a large number of variables that interact with one another in highly heterogeneous ways — and the unexpected properties that emerge. That’s complexity. A lot of complexity is about seeing how the whole works and adapts. You couldn’t do that with the differential equations or partial differential equations of the physics of the 19th and 20th centuries. You just couldn’t, at all.

So the computer is a kind of macroscope — the opposite of a microscope. We are in an era where there is a sea change in science from taking things apart to trying to put them back together again. Well, that’s not exactly new: Newton knew how to do this! He integrated his equations for celestial mechanics — but now we can do it for all kinds of things. Integrative science is here to stay and it’s going to grow.

I’ve read some criticisms of complex systems science as failing to deliver on its promise of revolutionizing science.

What happened at the Santa Fe Institute is like the development of the British railroads: first there was a boom and then there was a bust. And most of the railroad track got laid after the bust. So the Santa Fe Institute represents the boom and the bust: in its first five years we became famous; everybody beat their way to our doors to find out: what’s this new stuff you guys are doing? Then around six, seven years into it, people started to say, “yeah well, that’s new, but is it good for anything? It’s been hyped, and it’s been oversold.” I learned something important: that always happens! We’re now in the stage after the bust where there is an enormous amount of track to be laid with complexity science — and is it going to happen at UVM? You bet. With Maggie Eppstein as the director of the complexity group on campus — she’s terrific and there are a lot of smart people here.

Give me an example of how an understanding of complexity advances a field of science.

Take systems biology. Now that we’ve done the genome project, how do all the parts interact with one another to give you an organism? That’s an integrative task. There is a lot of work to be done.

And it’s turning out that cells may be dynamically critical — neither simple nor chaotic. This is amazing, but many biologists haven’t caught up with this yet; they’re just starting to come to terms with the idea that the cell is a dynamical system because molecular biology has been largely a local-function study: this protein binds to that piece of DNA and shuts off this gene or this protein touches that protein and gets phosphorylated, then this happens. It’s reductionism and it’s fine — but it hasn’t come to terms with complexity.

What you want to know is: how do genes regulate one another? And it’s a dynamical system: what does it do and become? Well that’s one of the big topics in systems biology; answers are going to emerge in complex systems science.

My passion is working on how cells get to be different from one another — cell differentiation — by genetic regulatory networks. I’ve now been working for five years on an idea that I started in 1971: that cancer may be unused cell types. I think we may be able to trick cancer cells into being normal. I call it differentiation therapy. And we’re doing it up in Calgary and I’d love to bring it on campus here at UVM in collaboration with Calgary. I think it’s a new way to try to treat cancer.

So all of this is complexity — but meanwhile so is the economy. The economy isn’t GDP; it’s a bunch of interwoven businesses. I’ve been thinking about the economy as a web of goods and services and I’ve published on the economy being subcritical or supercritical — like other energy systems.

Complexity is going to turn up in engineering in ways that I don’t know, but people here in the complexity group here do. How do you make adaptive robots? That’s complex.

I’m also interested in the origins of life; that’s part of complexity theory. I would love to see a program here on making self-reproducing molecular systems; it’s been done experimentally with proteins.

What holds complexity together theoretically? It seems to be this enormous polyglot beast! How is it different from the whole of human knowledge?

You are asking a totally relevant question to which there is not an adequate answer.

When coffee was discovered in the West, the Viennese asked: what are these green beans for? Because people thought it was brain food, they tried coffee on everything. Now we know it’s good to drink at Starbucks in the airport.

We’re going through this process right now with complexity and the macroscope of the computer, saying: what can we do with this?

I think it’s legitimate that complexity is hard to pin down; we don’t know yet! You’re right that somehow it’s the whole world. It’s everything that is not simple. Well, that’s a lot of things.

Do all these examples fit within the boundary of “normal” complexity?

Yes, mostly. Let’s call it “almost-normal” complexity. We’re getting to know the tools and the kinds of questions that can get asked and we know the kinds of answers that can be expected using these tools. We’ve drunk the coffee and begun to know what it’s good for. Now let’s get on with it, because there is an enormous amount of work to done within this normal or familiar complexity.

But what’s beyond this?

Yes, let’s look over the edge.

Consider the economy and the mess that we’re in. How do we make a model that has agencies that make regulations, agents that play the game according to the regulations, and that reveals the emergent properties given those regulations? And then to the fun part: the agents will find ways to beat the regulations, right? How do you capture that? That’s going beyond current complexity science and it’s part of the frontier. That has to do with whether agents — people — can be captured by an algorithm. I think the answer is no. I don’t think the human mind is algorithmic.

Do you know what Darwinian pre-adaptations are? These are unused features of an organism in its current selective environment, like swim bladders in fish or skin flaps on squirrels that allowed for the evolution of flying squirrels. They have no function originally but might turn out to be useful in some other environment.

The question is, can you say ahead of time: what are all possible Darwinian pre-adaptations? No, you can’t. And that means that we cannot make probability statements about how the biosphere will evolve by pre-adaptations, nor can we have laws for how the biosphere will evolve by pre-adaptations — even though it doesn’t violate any physical laws.

The becoming of the universe — because we’re part of it — is only partially describable by natural law. In its place is a huge creativity. I want to say that God is the natural creativity in the universe.

I think this means that not only do we not know what will happen; we often don’t know what can happen — like swim bladders or all sorts of technological evolution. There are limits to knowledge — and we have to live anyway.

Fodor, Nagel, and Plantinga don’t need to turn themselves into biochemists, but some awareness of the issues and advances would not be entirely misplaced.

By Michael Ruse, Chronicle Review, March 7, 2010

Last year was the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of his book, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. The anniversary was marked by conferences the world over. I will not tell you how many I attended; ecologically sensitive readers of The Chronicle might start whining about carbon footprints and that sort of thing. Let me just say that I found myself going no fewer than three times through the Quad City International Airport, in Moline, Ill. Moline!

I mention this as background to the publication of a new book by Jerry A. Fodor, a professor of philosophy at Rutgers University, and Massimo Piattelli-Palmarini, a professor of cognitive science at the University of Arizona. The title of the book, What Darwin Got Wrong (Farrar, Straus and Giroux), tells you their opinion of the old English naturalist and of his theory of evolution through natural selection. If Fodor and Piattelli-Palmarini were an isolated case, one could dismiss their book with a grimace (if you were a biologist), or welcome them with a cheer (if you were a creationist). But in the philosophical community, there is an increasingly vocal cadre of eminent philosophers harboring doubts about Darwin. To understand their critique, we must first put the clock back a year, to the beginning of the celebrations.

The anniversary conferences usually had a smattering of professional Darwin types like me—I am a historian and philosopher of science specializing in evolutionary theory—but the bulk of the presenters and attendees were evolutionary biologists. For two reasons, the atmosphere was universally positive. First, scientists deeply respect Darwin and his achievements. These people are evolutionists—they take the past seriously. Second, there was not a person at these conferences who was not excited about the science today. Evolutionary biology is on a roll, and that was a cause for celebration—and frenetic presentations that jammed in as much new science as possible. Moreover, to a person, the scientists saw that the first point led smoothly into the second. Everyone appreciates the tools of Darwinism, above all the mechanism of natural selection. But great science doesn’t stand still. It picks up and carries ideas and findings way beyond the wildest hopes of its founders. Evolutionary biology today is deeply Darwinian, but it has outpaced the Origin in ways that its author could never have imagined. To use a hackneyed phrase, Darwin gave biology a paradigm, and biologists have been expanding it ever since.

Here is some of the work I heard about. This is important for what I have to say in this essay. Peter and Rosemary Grant, emeritus professors of biology at Princeton University, have for many years been tracking and studying the finches of the Galápagos archipelago. The Grants have recently become more interested in speciation, when groups pull apart and set up reproductive barriers. Paleoanthropologists like Dean Falk, my colleague at Florida State University, have been studying the brain of the humanlike little beings recently discovered in the Indonesian archipelago, Homo floresiensis, better known as the hobbit. I also several times heard Donald Johanson, director of the Institute of Human Origins at Arizona State University, who, in 1974, discovered Lucy, a three-million-year-old female hominid skeleton. She walked upright yet had a brain the size of a chimpanzee’s. The buzz now is about the reconstructed Ardipithecus ramidus. Older than Lucy by about a million years, she, too, walked upright. She still lived a lot of the time in the trees, hence challenges earlier hypotheses about proto-humans moving out to the plains as the jungles dried up, and then needing to stand upright. Bipedalism came while we were still in the jungle.

Sean Carroll, a biologist at the University of Wisconsin at Madison and a master of evolutionary development ("evo devo"), and his team are turning up fantastic findings about how genes regulate development. The most exciting discovery in recent evolutionary biology is that humans and fruit flies, Drosophila, are remarkably similar at the molecular level, like DNA. Organisms really are built on the Lego principle, with the same building blocks: Go one way and get a human, another way and get a fly. Meanwhile evolutionary psychologists and anthropologists like Marc Hauser, at Harvard University, are studying moral behavior with such precision that they are able to pinpoint the parts of the brain involved in ration-al thinking, emotional reactions, and motivations. And, as always, the context is Darwinian. Why did natural selection push things this way rather than some other way?

Exciting times, which makes it all the more remarkable to hear voices from within the mainstream of philosophy questioning the veracity of evolutionary theory. I’ll mention three. First there is Alvin Plantinga. Although he teaches at the University of Notre Dame, a Roman Catholic institution, Plantinga is North America’s most distinguished Protestant philosopher of religion. A deeply sincere Calvinist, he has never hesitated to argue for his faith and has done groundbreaking work on questions of knowledge and belief. Even if you disagree with his conclusions, you can admire his skill and learn from his arguments. Plantinga, however, has long harbored a distrust, even an ardent dislike, of evolutionary theorizing in general and of Darwinian thinking in particular. In an essay published in 1999, he wrote, "Consider the role played by evolutionary theory in our intellectual world. Evolution is a modern idol of the tribe; it is a shibboleth distinguishing the ignorant fundamentalist goats from the informed and scientifically acquiescent sheep. Doubts about it may lose you your job. It is loudly declared to be absolutely certain, as certain as that the earth rotates on its axis and revolves around the sun—when it is no such thing at all."ause for The Chronicle Review

Plantinga is an open enthusiast of intelligent design, the belief that at some points in life’s history an intelligent being intervened to move the process along. I am not quite sure whether this makes him a full-blooded creationist, although he has in the past said he does not think it an impossible position. Some supporters of intelligent design, like Phillip E. Johnson, an emeritus professor of law at the University of California at Berkeley and author of Darwin on Trial (Regnery, 1991), seem to reject all forms of evolution. Others, like Michael J. Behe, a professor of biological sciences at Lehigh University and author of Darwin’s Black Box: The Biochemical Challenge to Evolution (Free Press, 1996), seem to accept a lot of common descent and might even be called theistic evolutionists, meaning that they think God guides the course of continuous development. Wherever Plantinga stands on this spectrum, he stands with the intelligent-design theorists in strongly emphasizing what they see as the falsity of Darwinian evolutionary biology.

Why does Plantinga feel this way? In his view, Darwinism implies that there is and can be no direction in life’s history. All change is a function of randomly appearing new variations (mutations) that are then sifted by the opportunistic mechanism of natural selection. Although new variations are not uncaused, they do not appear according to need. As Darwin himself argued, to think otherwise is to illicitly bring in a directing God. The late Harvard paleontologist Stephen Jay Gould used to pun that the arrival of the human species was entirely an accident brought on by our lucky stars—a comet that hit the earth 65 million years ago, wiping out the dinosaurs and allowing for the rise of mammals. It is precisely that kind of thinking to which Plantinga is opposed.

Plantinga’s reactions to evolutionary biology are disappointing but understandable. Disappointing because, generally speaking, Calvinists are favorable to science: It is all part of God’s sovereignty, and it is our task to discover his immutable laws. As the Victorians used to say about sexual intercourse, if God decided that we should reproduce in such a disgusting way, then it is for us to accept this fact and put it in context. The same can be said about Darwinian evolution. Plantinga’s views are understandable because philosophy today tends to be very secular, and there is a lot of sympathy for the claims of the so-called New Atheists—Richard Dawkins, Daniel C. Dennett, Sam Harris, Christopher Hitchens—that if you are a Darwinian, then you ought to be at least an agnostic, if not an outright atheist. Philip Kitcher, a professor of philosophy at Columbia University and author of Living With Darwin: Evolution, Design, and the Future of Faith (Oxford University Press, 2007), has spoken of Plantinga’s decision to blurb Johnson’s book as revealing "a combination of Schwärmerei [excessive sentiment] for creationist doctrine and profound ignorance of relevant bits of biology," which has caused Plantinga to put his brain "in cold storage."

Much more surprising is the position of the New York University philosopher Thomas Nagel, who has established himself right at the top of the field thanks to a long series of dazzling essays on topics as diverse as the thinking apparatus of a bat and the nature of sexual perversion. Although he states firmly that he does not believe in a deity, he has now come out against Darwinism. If Nagel is not a supporter of intelligent design, one wonders why he says what he does. He has endorsed a book by Stephen C. Meyer, Signature in the Cell: DNA and the Evidence for Intelligent Design (HarperOne, 2009), naming it one of the top books of 2009 in the Times Literary Supplement.

In a recent article, Nagel argues that it is proper to teach intelligent design in the classroom. Doubting the Darwinian claim that the sources of variation are undirected, Nagel quotes Behe as an authority. "Are the sources of genetic variation uniformly random or not? That is the central issue, and the point of entry for defenders of ID," Nagel writes. He goes on to tell us that Behe’s recent book, The Edge of Evolution, examines the "currently available evidence about the normal frequency and biochemical character of random mutations in the genetic material of several organisms."

Nagel leaves the reader with the impression that Behe’s concerns are well taken. Behe, according to Nagel, argues that "widely cited examples of evolutionary adaptation, including the development of immunity to antibiotics, when properly understood, cannot be extrapolated to explain the formation of complex new biological systems. These, he claims, would require mutations of a completely different order, mutations whose random probability, either as simultaneous multiple mutations or as sequences of separately adaptive individual mutations, is vanishingly small."

Like Plantinga, Nagel is skeptical about the whole evolutionary enterprise. Suppose someone says that doubting evolutionary theory is equivalent to thinking the earth is flat. Nagel writes: "This seems to me, as an outsider, a vast underestimation of how much we do not know, and how much about the evolutionary process remains speculative and sketchy." He goes on to tell us that those who think we are now well on the track to understanding the mechanisms of evolution are wrong: "Nothing close to this has been done." And in a comment to which I shall refer below, he writes: "A great deal depends on the likelihood that the complex chemical systems we observe arose through a sufficiently long sequence of random mutations in DNA, each of which enhanced fitness. It is difficult to find in the accessible literature the grounds for evolutionary biologists’ confidence about this."

Naturally the origin-of-life issue is raised—and found wanting ("a complete scientific mystery at this point"). It is hardly surprising, therefore, that Nagel thinks that evolutionary biology is more happily accepted by nonbelievers than by theists: "This is just common sense."

Jerry Fodor, no less distinguished than Nagel and Plantinga, is well known for his claim that the mind is composed of separately functioning modules. And he, too, has taken to criticizing Darwinian theory, first in an article in the London Review of Books and now in What Darwin Got Wrong. Fodor finds something deeply flawed in contemporary evolutionary thinking: "An appreciable number of perfectly reasonable biologists are coming to think that the theory of natural selection can no longer be taken for granted. This is, so far, mostly straws in the wind; but it’s not out of the question that a scientific revolution—no less than a major revision of evolutionary theory—is in the offing."

To Fodor the notion of natural selection is flawed. He has long been on record arguing that metaphors in science are misleading, and that they must be eliminated as science matures. In the case of Darwinism, we have an analogy or metaphor at work, between the artificial selection that breeders use when they improve livestock—shaggier sheep, beefier cows—and the process of differential reproduction that Darwinians think leads to evolutionary change (in the direction of adaptive advantage). Fodor believes that differential reproduction illicitly brings mind into the natural process:

The present worry is that the explication of natural selection by appeal to selective breeding is seriously misleading, and that it thoroughly misled Darwin. Because breeders have minds, there’s a fact of the matter about what traits they breed for; if you want to know, just ask them. Natural selection, by contrast, is mindless; it acts without malice aforethought. That strains the analogy between natural selection and breeding, perhaps to the breaking point. What, then, is the intended interpretation when one speaks of natural selection? The question is wide open as of this writing.

Fodor argues that this problem is insoluble. Fortunately we need not worry much, because in going with selection, evolutionists have been grasping the wrong end of the stick. In his view, today’s proper-thinking evolutionary biologists are finding that it is all in the variations anyway. All evolutionary change comes about through the genes and their development. Even if natural selection were at work, Fodor argues, the most it could do is clean up afterward.

What does one say about these critics? One could certainly pick apart individual things, for instance Fodor’s claims about selective breeding versus natural selection. The very last thing that Darwin and his followers are trying to do is put mind into nature. In both artifice and nature, some organisms are going to reproduce and others are not, and the reasons for that are (on average) going to be connected to the different features of the winners and losers. To say that a speckled moth is less likely to be eaten by a robin than a dark moth, because the robin can less easily see the speckled moth against the lichen-covered tree, is to say nothing about God or any other conscious being.

One could also pick up on the fact that neither Plantinga nor Nagel seems to have the slightest awareness of the scientific criticisms that have been launched against intelligent design. Every example that supporters of intelligent design produce to suggest that natural causes are not adequate—the bacterial flagellum, the blood-clotting cascade—has been shown to be the exquisite end result of evolution. And one could certainly groan at the tired suggestion that Darwinians are unaware of or threatened by developments in evolutionary development. No evolutionary biologist, least of all Sean Carroll, suggests that one day the eye just appeared. However the new sources of variation play out, selection is going to be there right along with them.

But rather than work over the details, I want to draw attention to the way this crop of critics ignores evolutionary biology—aside from the kind of cherry-picking in which Fodor engages. Nagel may sneer about the failure to find "accessible literature" that answers his worries. In what part of the library was he doing his literature search? Where, for example, is any discussion of the Grants’ work on the Galápagos finches? What about a detailed look at the new scholarship that is challenging earlier thinking about the evolution of bipedalism? What about the discoveries of molecular biology and of the similarities (homologies) between humans and fruit flies? And why no mention of Marc Hauser and his work uncovering the secrets of moral thinking? There is a deafening silence on those and other issues. Fodor, Nagel, and Plantinga don’t need to turn themselves into biochemists, but some awareness of the issues and advances would not be entirely misplaced.

This total lack of interest in the science is surely suggestive. The critics are being driven by other, for them deeper, concerns. And as an evolutionist, I turn to the past for clues. What fueled the initial opposition to Darwin was a concern with our species, with Homo sapiens. For 150 years, since the Origin, critics have feared that we humans might become part of the evolutionary picture—not just our bodies, but our minds, our very souls. What makes us distinctively and uniquely human? This worry is still alive and well in today’s philosophical community. Plantinga is open in his fear that Darwinism makes impossible the guaranteed existence of our species. More, for years he has argued that Darwinism is bound up with the metaphysical belief that everything is natural (as opposed to supernatural), and that this leads to a collapse of rational belief and knowledge. The chance elements in Darwinism are simply not compatible with Plantinga’s Christian faith.

As nonbelievers, Nagel and Fodor are a bit different, but not that different. For years Nagel has argued against a reductive view of the human mind, believing it to be more than just molecules in motion—the obvious end result of Darwinism. At some level, Nagel believes, the mind is above the material. It is perhaps a stretch, but probably not too much of a stretch, to say that the kind of sympathetic attitude that Nagel takes toward intelligent design points not so much to a concealed theism (akin to Plantinga’s open theism) as to a kind of vitalism, in which there are nonnatural, nonphysical forces that direct things in the material world.

And then there is Fodor. The final section of his new book is very revealing. As a dreadful warning to those who do not accept his main conclusions, Fodor prints passage after passage of claims by Darwinians that one can understand human nature and thinking as the product of natural selection: This is where we will all end up if we don’t stop the rot right now. My suspicion is that Fodor doesn’t really give a damn about fruit flies or finches or anything else out there. But when it comes to Homo sapiens, he wants no part of a naturalistic explanation that reduces design to the workings of blind law. There may not be a God, but we sure are made in his image.

I often joke, as one who spends a lot of time fighting creationists, that when one of them says something silly, that means more work for me: bread on the table. When one of them says something really silly, there is strawberry jam, too. In 2005, after a trial in Dover, Pa., a federal judge ruled that intelligent design should not be taught in schools. Pat Robertson’s response—"God is tolerant and loving, but we can’t keep sticking our finger in his eye forever. If they have future problems in Dover, I recommend they call on Charles Darwin. Maybe he can help them"—kept me and my family well fed for weeks.

Now those of us who love Darwin and his theory have got the philosophers to deal with, too. I see steak in my future. But in truth, I am not really happy. I might even turn vegetarian if I could persuade my fellow philosophers to start taking science seriously. Could they possibly entertain the idea that being at one with the living world does not make us any less worthy as human beings? After the Origin was published, the wife of the Bishop of Worcester supposedly reacted: "Descended from monkeys? Let us hope that it is not true. But if it is true, let us hope that it not become widely known."

A century and a half later, the time has come to shout the truth from the rooftops.

Michael Ruse directs the program in the history and philosophy of science at Florida State University. His latest book, Science and Spirituality: Making Room for Faith in the Age of Science, was just published by Cambridge University Press. He contributes to The Chronicle Review’s blog, Brainstorm.

Natural selection’s secular critics get it wrong

What Darwin Got Wrong
Jerry Fodor and Massimo Piatelli-Palmarini
Farrar, Straus and Giroux, $26 (cloth)

Ned Block and Philip Kitcher

Boston Review, March/April 2010

In On the Origin of Species, published in 1859, Charles Darwin made two remarkable scientific contributions. First, he presented an overwhelming case for the relatedness of all living things. Biological diversity, he argued, results from a process of “transmutation” of species—via “descent with modification.” Second, he recognized that the basic mechanism of such change is natural selection: a combination of variations in traits and a selective retention of the variations that contribute to reproductive success.

Descent with modification was accepted quickly. As early as 1872, Thomas Henry Huxley described Darwin as having achieved a revolution comparable to that brought about by Newton’s Principia. Natural selection, by contrast, remained controversial until the 1930s, when Darwin’s ideas were integrated with the genetics of Gregor Mendel and Thomas Hunt Morgan, creating the “Modern Synthesis.” More than 70 years later, thanks to a proliferation of evolutionary explanations and significant new theoretical contributions, the fundamentals of evolutionary biology are reasonably well settled.

To be sure, religiously inspired opposition to evolution persists. Although religious opponents seem to have accepted—at least officially—the relatedness of organisms, proponents of “intelligent design” continue to insist that natural selection is unable to explain some prominent instances of evolutionary change. Their skepticism is based on alleged examples of “irreducible complexity”—an intricate interdependence in the features of organisms that supposedly cannot be explained by Darwinian mechanisms of step-by-step improvement.

Other critics—more sophisticated and scientifically informed—wonder whether natural selection explains as much about evolution as biologists commonly assert. They urge, for example, that causes other than natural selection (such as genetic drift) are important in explaining evolution. Or they argue—overemphasizing something all evolutionary biologists agree with—that natural selection operates against a background of constraints, perhaps stemming from features of genomes. Darwin himself was aware of these complexities about the role of natural selection, and throughout the Origin laments his own ignorance about the extent of that role and what alternative causes of evolutionary change there are. His awareness of how much he did not know led him to cautious formulations: for example, he writes, “Natural Selection has been the main but not exclusive means of modification.”

As in other areas of science, then, lively debate continues, and an interest in deeper and more comprehensive understanding moves the field forward. But even as some scientists suggest that natural selection may be limited in ways Darwin could not envisage, they accept his basic insights and work to improve our biological understanding within the framework he set forth.

In their controversial new book, What Darwin Got Wrong, Jerry Fodor and Massimo Piattelli-Palmarini set out to dismantle that framework. They argue that standard evolutionary thinking—what they call Darwinism—is guilty of a basic logical error, not a mistake in biology but an “intensional fallacy.” That fallacy, they say, undermines the entire enterprise. To be clear, the authors preface their demolition with a disclaimer: in attacking Darwin, they are not supporting any religious view of “origins”; thoroughgoing materialists, they do not think that biological patterns require an intelligent designer. But their criticisms are intended to knock evolutionary theory from its scientific pedestal by demolishing the scientific credentials of natural selection.

Fodor and Piattelli-Palmarini are not biologists. Fodor is a leading philosopher of mind and cognitive scientist, best known for his ideas about the modularity of mind and language of thought; Piattelli-Palmarini is a cognitive scientist. They do not have new data, new theory, close acquaintance with the everyday practice of evolutionary investigations, or any interest in supplying alternative explanations of evolutionary phenomena. Instead, they wield philosophical tools to locate a “conceptual fault line” in contemporary Darwinism. Apparently unshaken by withering criticism of Fodor’s earlier writings about evolutionary theory, they write with complete assurance, confident that their limited understanding of biology suffices for their critical purpose. The resulting argument is doubly flawed: it is biologically irrelevant and philosophically confused. We start with the biology.

• • •

In 1979 evolutionary biologists Stephen Jay Gould and Richard Lewontin published an influential article, criticizing what they called the “adaptationist programme” in evolutionary theory. Some of their contemporaries, they lamented, were much too quick to accept stories about the adaptive advantage of every trait of an organism. According to Gould and Lewontin, adaptationists suppose that every trait contributes to an organism’s reproductive success (its fitness), and exists because of that contribution.

Gould and Lewontin’s critique of adaptationism begins with the observation that the characteristics of organisms are often correlated with one another. Because of those correlations, they argued, evolutionary biologists need to explore the possibility that an allegedly favorable characteristic might be a side effect of something else (a “correlation of growth,” Darwin said). Entering the basilica of San Marco, you might marvel at the wonderful use of spandrels—the tapering triangular spaces filled with mosaics where the dome adjoins the columns. (Too much ink has already been spilled about whether the term “spandrels,” usually confined to two-dimensional spaces, should be used to cover the three-dimensional pendentives in San Marco. We will spill no more.) Struck by the spandrels, you might conclude that the architect designed those spaces so that they could contain mosaics showing the four evangelists.

The basic problem, according to Fodor and Piattelli-Palmarini, is that the distinction between free-riders and what they ride on is ‘invisible to natural selection.’

As Gould and Lewontin observed, however, spandrels are not the result of a design: if you have arches supporting a dome, you also have spandrels. Spandrels are hitchhikers on arches-plus-dome. Or, to take one of Gould and Lewontin’s biological examples, consider the diminutive front legs of the tyrannosaurus. Instead of inventing an adaptive story (“the legs promoted the skill of tyrannosaurus males in sexual foreplay”), the reduction of size may simply be a byproduct of increased growth rates elsewhere. The problem for adaptationism is that it can be hard to know which trait was selected for and which was the free-rider: maybe architects wanted spandrels in order to display mosaics, and built arches-plus-dome as a solution; maybe the tiny legs are for mating, and produce huge hind limbs and an impressive tail as byproducts.

In the architectural case, we can be fairly sure of the intentions of the builders, and so conclude that the use of the spandrels for mosaics was an afterthought. But in a natural case we would need to know how differences in reproductive success were brought about before we could distinguish the selected-for traits from the free-riders. Gould and Lewontin think that we can sometimes figure out the answer, and urged evolutionary biologists to do so by remaining mindful of all the tools provided by Darwin and his successors rather than falling back on an easy adaptationism.

Fodor and Piattelli-Palmarini believe that the spandrels problem is much deeper. While Gould and Lewontin had a nice insight about “correlations of growth,” they ultimately affirmed a “very sophisticated kind of adaptationism” because they took for granted that there can be a genuine fact about which of two correlated properties—say, large hind-quarters and tiny forelimbs—is selected for and which is a free-rider.

The basic problem, according to Fodor and Piattelli-Palmarini, is that the distinction between free-riders and what they ride on is “invisible to natural selection.” Thus stated, their objection is obscure because it relies on an unfortunate metaphor, introduced by Darwin. In explaining natural selection, the Origin frequently resorts to personification: “natural selection is daily and hourly scrutinising, throughout the world, every variation, even the slightest” (emphasis added). When they talk of distinctions that are “invisible” to selection, they continue this personification, treating selection as if it were an observer able to choose among finely graded possibilities. Central to their case is the thesis that Darwinian evolutionary theory must suppose that natural selection can make the same finely graded discriminations available to a human (or divine?) observer.

Neither Darwin, nor any of his successors, believes in the literal scrutiny of variations. Natural selection, soberly presented, is about differential success in leaving descendants. If a variant trait (say, a long neck or reduced forelimbs) causes its bearer to have a greater number of offspring, and if the variant is heritable, then the proportion of organisms with the variant trait will increase in subsequent generations. To say that there is “selection for” a trait is thus to make a causal claim: having the trait causes greater reproductive success.

Causal claims are of course familiar in all sorts of fields. Doctors discover that obesity causes increased risk of cardiac disease; atmospheric scientists find out that various types of pollutants cause higher rates of global warming; political scientists argue that party identification is an important cause of voting behavior. In each of these fields, the causes have correlates: that is why causation is so hard to pin down. If Fodor and Piattelli-Palmarini believe that this sort of causal talk is “conceptually flawed” or “incoherent,” then they have a much larger opponent then Darwinism: their critique will sweep away much empirical inquiry.

We can clarify their criticism of what natural selection can see by translating it into causal language that avoids personification. Their specific charge is that, with respect to correlated traits in organisms—traits that come packaged together—there is no fact of the matter about which of the correlated traits causes increased reproductive success. In other words they appear to be making the very ambitious claim that whenever there are correlated traits there is no fact of the matter about which of the traits causes any effect.

Consider the famous case of industrially induced melanism in the peppered moth. Supposedly, in landscapes where pollution has destroyed the lichens on the trunks of trees, melanic (black) variants of the moth are better camouflaged when they rest on tree trunks than their lighter, speckled relatives. With improved camouflage, birds and other predators are less likely to pick the moths off the tree trunks. In polluted environments, then, melanic moths are more likely to survive, and hence to leave descendants in later generations. So far, so familiar.

Enter Gould and Lewontin. Maybe moth coloration is a spandrel, and some other property of the moths is both relevant to their proliferation and correlated with their color. For example, evolutionary biologists have observed that moths usually rest by day on the undersides of branches rather than on the trunks of trees. So is the familiar black-as-camouflage story really true? Perhaps a characteristic of the larvae of melanic moths makes them more likely to survive. Or perhaps melanic moths have a tendency to move around less at night, which makes them less vulnerable to being eaten by bats (who care nothing for color). These are interesting alternatives to the familiar story, and the causal hypotheses they introduce can be tested in obvious ways: by examining the rates of larvae survival or by investigating nocturnal motions of moths. And this is what biologists have done. Concerned that an apparent adaptation (a camouflaging color) may be a side effect, they have looked for correlated traits that might figure in some alternative process that would culminate in greater representation of the melanic moths. Despite some controversy in the 1990s, the traditional story seems to be standing up well.

If Fodor and Piattelli-Palmarini acknowledge the evidence that favors the camouflaging-color hypothesis over the moth-larvae and moth-mobility hypotheses, they will have to say that the biologists have not been imaginative enough—that they have overlooked some other correlated trait for which there could be no fact of the matter about whether it, or the black coloration, caused the reproductive success.

What exactly could this trait be? One possibility, suggested by remarks in some of Fodor’s previous writings, would be that there are two different properties: being black, on the one hand, and matching the environment on the other. Is there a fact of the matter as to which of these causes the reproductive success?

There are two ways to interpret the question, and each one has a good answer. The first focuses on the specific environments in which melanic moths are selected: the woods that have suffered from industrial pollution. In these environments, being-well-camouflaged and being-black come to more or less the same thing. In a polluted environment, a black moth matches the surroundings better than a lightly speckled moth. The result is less predation and hence increased survival and procreation. Biology focuses on the process, and biologists are quite willing to identify how selection is acting by picking out any feature of the organisms that is central to the process. So if you are focused on this specific environment, then it is a matter of indifference whether you talk of selection for black color or for camouflage or for decreased predation. Among these options, you can talk as you like. Any of them will distinguish the selection process of the traditional industrial-pollution story from the potential rivals, such as larval resilience, or lower nocturnal mobility.

A second interpretation would consider all the woody settings in which the moths can be found. Speckled moths will be at a disadvantage if they rest on polluted trees (they will be picked off more easily), and melanic moths will be similarly vulnerable in unpolluted surroundings. Biologists can test and confirm these causal facts, and can report their conclusions by finding that, across the whole spectrum of environments, matching the color of the trees causes increased reproductive success. Of course, saying that accords perfectly with, and generalizes in a particular direction, the thought that, in the polluted woods, being black causes a moth to match its environment better. There are no great mysteries, no inscrutable distinctions between spandrels and properties selected, no general troubles about distinguishing between the causal powers of correlates.

Why then do Fodor and Piattelli-Palmarini think that problems about selection-for are omnipresent? Because they envisage a vast space of properties and expect proponents of natural selection to discriminate among all the rivals. Not only is there a property of being-a-melanic-moth, there is also a property of being-a-melanic-moth-and-smaller-than-Manhattan. These properties are not only correlated in the world’s actual moth populations, they are correlated universally. Maybe it is impossible, even with the most rarefied genomic technology, to build a moth bigger than Manhattan. If so, the correlation between these properties could not be broken. How then could there be a sense in which one of the properties—being-a-melanic-moth—rather than the other—being-a-melanic-moth-and-smaller-than-Manhattan—caused the increased reproductive success?

We suggest that the question deserves a shrug. Serious evolutionary biology is concerned with comparative causal claims among interestingly different alternatives. Is it the black coloration rather than the larval resilience or the nighttime lethargy? Good question. Is it the coloration rather than coloration-and-being-smaller-than-Manhattan? Silly question. Fodor and Piattelli-Palmarini create the idea that natural selection is a fine-grained discriminatory enterprise that distinguishes among all the properties philosophers can discover (or invent?) precisely so they can demolish it. The authors’ error is to note correctly that there is some indeterminacy and then to conclude that indeterminacy is total: that there can be no matter of fact with respect to causal efficacy as between any of a set of correlated properties. Evolutionary theory, Fodor and Piattelli-Palmarini say, contains, at its core, a causal notion—selection-for—that picks out the properties that cause increased reproductive success. They then declare that there is no fact of the matter about what causes increase reproductive success when the candidate properties are correlated with others. But correlation is omnipresent, so evolutionary biology totters.

This critique makes no contact with the practice of evolutionary biology, where the focus is on the causal processes (for example, camouflage) that lead to reproductive success, the salient properties (say, melanism) that play a role in them, and whether other causal processes (say, stillness at night) might have been at work.

• • •

A different example (due to the philosopher Elliott Sober) can offer further clues to the ways in which the authors inflate the position they attack. Sieves are very simple selection devices. Imagine a sieve with a mesh that will allow balls with radii of one inch to fall through, but that will retain those that are even a tiny bit larger. Suppose that balls with several different radii—one inch, two inches, three inches, and four inches—are placed in the sieve. The one inch balls are blue, while the larger ones have different colors. The blue balls fall through, and the others remain. In one sense the sieve has “selected” the blue balls, although it has not “selected for” being blue. That is because size not color is what matters to the transmission. Using the language Fodor and Piattelli-Palmarini employ, we might say that the property of having a particular color (blue) is a spandrel or free-rider.

Yet we might divide the properties up more finely. The balls with radius one inch have a diameter of two inches, a circumference of 2π inches, a cross-sectional area at the equator of π square-inches, a volume of 4π/3 cubic inches, etc., etc. Lots of geometrical properties are correlated—indeed perfectly so. Which of these properties caused the balls to fall through? The question is idle. A person could select for radius rather than diameter, but the sieve cannot. Yet that makes absolutely no difference to the judgment originally made: the sieve selects for size, rather than for color. To recur to the language of indeterminacy, there is a determinate matter of fact as between color and size but not as between radius and diameter.

If Fodor and Piattelli-Palmarini’s criticism is taken seriously, then there are no facts of the matter about causal claims in any field of inquiry.

Just as ordinary people recognize that sieves select for size and not color, evolutionary biologists work hard to discover the mechanisms at work in producing increased frequency of types of organisms. They are happy if they can trace the prevalence of melanic moths to coloration, camouflage, and decreased predation rather than to superior survival of larvae. They remain unperturbed when asked if it is coloration rather than camouflage, or rather than lowered predation, or rather than being-melanic-and-smaller-than-Manhattan.

We can know the fact that the sieve selects for size rather than color without the presence of any actual environments in which size and color are not correlated because we understand the causal mechanisms: we know what would have happened if size and color were de-correlated in this device, namely, there would still be selection for size rather than color. A real causal difference is a feature of the world that can be investigated in different ways, for example, by looking at mechanisms; by considering real cases of de-correlation; or by looking at cases where the selection pressures are slightly different, such as unpolluted environments in which light moths are at a disadvantage. The way evolutionary biologists think about causation allows for the discussion of causal process in any of a number of ways—even those strange ways that invent peculiar properties. Fodor and Piattelli-Palmarini almost grasp this point where they discuss the “prima facie” plausibility that polar bear color is a result of selection for matching the environment rather than selection for whiteness, a difference that, as we saw in the analogous case of the moths, can be real and can be investigated.

Have we dismissed the questions the authors would foist on evolutionary biology too quickly? We think not. As already noted, if their concerns are taken seriously, correlated properties pose a general problem. For example, since human beings are smaller than Manhattan, the properties being-obese and being-obese-and-smaller-than-Manhattan are perfectly correlated in the human population. So there are no facts of the matter about causal claims in epidemiology. And the same goes for atmospheric science, geology, engineering . . . and, indeed, everything else.

• • •

Despite the powerful claims of evolutionary biologists and all other scientific investigators, suspicion might linger that these insightful outsiders have identified commitments the practitioners have missed, that they have exposed presuppositions that have gone unrecognized because of the fuzziness of everyday reflections. To address such suspicions, we need to treat Fodor and Piattelli-Palmarini’s critique in its own terms. Setting the scientific practice to one side, let’s see if they have the philosophy straight.

They allege that Darwinism is guilty of an “intensional fallacy.” To explain what they have in mind, we need to introduce two ideas: intensionality and coextensive properties.

The authors introduce intensionality by considering the substitution of terms for one another in sentences. There are some sentences in which, if you substitute one name for another, and both are names for the same thing or person, you always go from a true sentence to a true sentence, or from a false sentence to a false sentence. “Madonna” and “Louise Ciccone” name the same person. The sentence “Madonna is a woman” is true. If you substitute “Louise Ciccone” for “Madonna,” you obtain the sentence “Louise Ciccone is a woman,” which is also true. Not all sentences work this way. Our world is full of people who do not know that Madonna is Louise Ciccone. If Bert is one of these people, then the sentence “Bert believes that Madonna is a star” may well be true, even though “Bert believes that Louise Ciccone is a star” is false.

This phenomenon is not a trivial linguistic matter but actually reveals something deep about something real. Thinking that someone is a star always works via some specific way of thinking of the person; you may think of the person under another guise as well, and under that guise you may not think the person is a star. An important feature of our thought—that we can think about the very same things under very different guises—is expressed by the linguistic facts. There are some contexts, such as “ is a woman,” in which substitution of names that name the same entity preserves truth (or falsehood); these contexts are said to be extensional. Other contexts, such as “Bert thinks that is a star,” allow for changes from truth to falsehood under similar substitutions; these are intensional.

The authors’ entire argument depends on their claim about the intensionality of selection-for. Are they right about this?

Now for the second piece of terminology: two properties are said to be coextensive if and only if they apply to exactly the same objects. Such properties are (in the more familiar terminology we used earlier) correlated. Being-a-melanic-moth-and-smaller-than-Manhattan is coextensive with being-a-melanic-moth; being a sphere whose radius is less than one inch is coextensive with being a sphere whose diameter is less than two inches.

Turning from terminology to substance, Fodor and Piattelli-Palmarini’s central thesis is that selection-for is intensional:

There can be coextensive but distinct phenotypic properties, one (but not the other) of which is conducive to fitness, but which natural selection cannot distinguish. In such cases, natural selection cannot, as it were, tell the arches from the spandrels. That being so, adaptationist theories of evolution are unable, as a matter of principle, to do what they purport to do: explain the distribution of phenotypic traits in a population as a function of its history of selection for fitness.

The idea is that natural selection will favor individual organisms which carry both of two coextensive properties: having large hind-quarters and having diminutive front legs. Since all individuals who have one of the two coextensive properties must have the other as well, their reproductive success will not distinguish the two properties. But selection-for requires distinguishing such coextensive properties: the large hind legs and tail are selected-for, the tiny front legs are not. That is what the authors mean when they say that selection-for is an intensional context.

Here, then, is the problem restated: the causal processes at work in evolution cannot distinguish between coextensive properties, but selection-for requires that they be distinguished. In cases of selective breeding (or church architecture), the breeder (or architect) knows what he is selecting for, and that distinguishes the two coextensive properties. In natural selection, however, there are no intentions of a breeder to appeal to, no intelligent designer, no architect who is aiming to build a dome and happily creating spandrels as necessary byproducts. We cannot appeal to the intentions of Mother Nature, so the intensionality must come from something else: Fodor and Piattelli-Palmarini suggest that the only possibilities are to suppose that there are laws of nature or facts about how things would have been under somewhat different circumstances that determine that one, but not the other, of the coextensive properties is the property selected for.

Fodor and Piattelli-Palmarini take this intensionality of selection-for to be central to Darwinian theorizing:

Not just selection-for but a whole galaxy of other concepts that adaptationist explanations routinely employ suffer from the same disease. These include, notably, such notions as ‘ecological niche’, ‘problem of adaptation’ and ‘biological function’, all of which are interdefined with ‘selection-for’ and thus inherit the problems that intensionality occasions.

The upshot is that intensionality sinks the whole apparatus of evolutionary theorizing: “Darwinists have a crux about free-riding because they haven’t noticed the intensionality of selection-for and the like; and when it is brought to their attention, they haven’t the slightest idea what to do about it.”

Describing the issues this way simply restates in technical philosophical terms the basic charge: in the face of spandrels, evolutionary theory requires that there be a process that makes discriminations that natural selection cannot make. So the entire argument depends on the authors’ claim about the intensionality of selection-for. Are they right about this?

In a word, no. In the only way that matters for evolutionary biology, selection-for is extensional rather than intensional—and this suffices for making sense of the use made in evolutionary thinking of the notion of selection-for and correlative notions such as adaptation and biological function.

To see why, consider the notion of causation. If decreasing temperature causes freezing and decreasing temperature is the same property as decreasing mean molecular kinetic energy, then decreasing mean molecular kinetic energy causes freezing. The causal powers of a property—temperature, say—do not depend on how we refer to it or think about it. In that respect, causation is extensional.

But if causation is extensional, then so is selection-for, since selection-for is a causal idea. Consider, once again, the sieve and the balls. The balls that are blue and small fall through, leaving the larger (and differently colored) spheres in the sieve. What is causally responsible for the blue balls passing through the sieve is that they are small, not that they are blue; what is selected for is smallness, not blueness. In sum: being small is the cause, just as being black is the cause of the moths’ reproductive success rather than (say) correlated nighttime lethargy.

Why, then, do Fodor and Piattelli-Palmarini think selection-for is intensional? Perhaps because they are drawing the line between intensional and extensional in a way different from ours, and on their way of drawing the distinction both causation and selection-for come out as intensional. Suppose having-a-heart is coextensive with having-a-kidney: every animal with a heart is also an animal with a kidney and vice versa. Consider “Ernie has a heart, and that caused the blood to flow through his veins. Substituting “has a kidney” for “has a heart” in that context would yield a falsehood: Ernie’s blood does not flow through his veins because he has a kidney. Because of this failure of substitution, we might describe causation as intensional (in a different sense from the one we originally explained). But this kind of failure of substitution is of no significance for evolutionary theory, as we will now see.

When we introduced the notions of intensionality and extensionality, we did so by talking about substitutions of terms that name the same entity. If the substitution of a term leads from truth to falsehood (or from falsehood to truth), even though the term substituted names the very same thing as the term it replaces (as with Bert’s musings on Madonna), that fact is significant because it reveals something important about our thought: that we think about things under guises. It is a quite different matter to consider contexts in which you cannot always replace one term associated with a property with another term associated with a different property that applies to exactly the same things, with preservation of truth and falsity. Different properties—having-a-heart, having-a-kidney—can apply to exactly the same objects. When you are interested in causation, however, you are not concerned about guises. What is of concern is the identity of the causing property. Having a heart but not having a kidney is causally efficacious in pumping blood, no matter how you describe having a heart. What we have are not two guises for the same thing, thus not intensionality in our sense, but two distinct properties that apply to the same things.

If the authors want to mind their neighbors’ business, they should spend a little time discovering just what those neighbors do.

The authors are entitled to pick how they want to use the term “intensional.” Maybe they will suppose (as we do) that intensionality is marked by the failure to preserve truth (or falsehood) when terms are replaced by other terms that name the same thing—when one guise is substituted for another. Or perhaps they will prefer a different notion, signaled by failure to preserve truth (or falsehood) when terms that are associated with distinct but coextensive properties are substituted. The essential point is that however they choose, causation and selection-for always travel together. If they take the first approach, both will be extensional; if they opt for the second, both will be intensional. Their argument turns on mixing criteria, taking one version in one place and a different one elsewhere.

We can explain the notion of selection-for in evolutionary reasoning so that both selection-for and causation are extensional. Further, on this way of reconstructing both notions, there can be a fact about which of two correlated properties is selected for and which is a free-rider. Fodor and Piattelli-Palmarini’s argument collapses.

As mentioned earlier, they think that because of the extensionality of causation and the intensionality of selection-for, causation alone cannot be the basis of selection-for, so appeal must be made to something else—the intentions of a breeder or claims about what might have been or laws of nature. As a result, their book is filled with discussions of philosophical issues about contrary-to-fact claims and scientific laws. But all of these discussions—lengthy and obscure—explore ways out of a false impasse. They are needed only because of the authors’ misunderstandings of the basic issue: that selection-for is a causal notion, and, since causation is extensional, so is selection-for.

That said, however, one final detail bears notice: although contexts of causation and selection-for are extensional in the respect mentioned, contexts of explanation are notoriously intensional. Does that mean that there can’t be evolutionary explanations? Not at all. Nature determines which properties are causally efficacious, and hence what is selected for. Then we theorists can find out about this and give explanations based on what is selected for. Thus if nature tells us that it is melanic color rather than larval resilience or nightime lethargy that was selected for, then we thinking beings can give (intensional) explanations in terms of melanic color rather than the other properties. In giving the explanation, we (thinking beings) describe the property in our preferred way.

• • •

Fodor and Piattelli-Palmarini take the role of philosophy to consist in part in minding other people’s business. We agree with the spirit behind this self-conception. Philosophy can sometimes help other areas of inquiry. Yet those who wish to help their neighbors are well advised to spend a little time discovering just what it is that those neighbors do, and those who wish to illuminate should be sensitive to charges that they are kicking up dust and spreading confusion. What Darwin Got Wrong shows no detailed engagement with the practice of evolutionary biology, nor does it respond to the many criticisms that have been leveled against earlier versions of its central ideas. In this latter respect, the authors resemble the creationist debaters who assert that evolution is incompatible with the second law of thermodynamics, hear detailed refutations of their charge, and repeat their patter in the next forum.

We admire the work that both Jerry Fodor and Massimo Piattelli-Palmarini have produced over many decades. We regret that two such distinguished authors have decided to publish a book so cavalier in its treatment of a serious science, so full of apparently scholarly discussions that rest on mistakes and confusions—and so predictably ripe for making mischief.