Brandon Keim - Evolution’s Contrarian Capacity for Creativity

From Nautilus, Facts So Romantic on Biology, this is an interesting article on creativity in evolution. The author begins with two small songbirds - small songbird known as the willow tit, closely related—Poecile montanus to Poecile atricapillus—to the black-capped chickadee.

To the naked eye, there’s not much to distinguish between them. Both are small, with black-and-white heads and gray-black wings, seed-cracking bills, and a gregarious manner. For a long time, they were even thought to be the same species. The only obvious difference, at least with the willow tit I saw, was a duskier olive underbelly coloration.

These two nearly identical birds are a nice jumping off place for a discussion of diversity in evolution.

Evolution’s Contrarian Capacity for Creativity

Posted By Brandon Keim on Jul 02, 2014


The easily confused willow tit and black-capped chickadee f.c.franklin via Flickr / Brandon Keim
ONE OF MY favorite pastimes while traveling is watching birds. Not rare birds, mind you, but common ones: local variations on universal themes of sparrow and chickadee, crow and mockingbird.

I enjoy them in the way that other people appreciate new food or architecture or customs, and it can be a strange habit to explain. You’re 3,000 miles from home, and less interested in a famous statue than the pigeon on its head?! Yet there’s something powerfully fascinating about how familiar essences take on slightly unfamiliar forms; an insight, even, into the miraculous essence of life, a force capable of resisting the universe’s otherwise inevitable tendency to come to rest.

Take, for example, a small songbird known as the willow tit, encountered on a recent trip to Finland and closely related—Poecile montanus to Poecile atricapillus—to the black-capped chickadee, the official bird of my home state of Maine. To the naked eye, there’s not much to distinguish between them. Both are small, with black-and-white heads and gray-black wings, seed-cracking bills, and a gregarious manner. For a long time, they were even thought to be the same species. The only obvious difference, at least with the willow tit I saw, was a duskier olive underbelly coloration.

Which raises a question, asked by Darwin and J. B. S. Haldane and generations of biologists since: Why? Why is a bird, similar in so many ways to another, different in this one? It’s a surprisingly tricky question.

Generally speaking, we tend to think of evolution in purposeful terms: There must be a reason for difference, an explanation grounded in the chances of passing on one’s supposedly selfish genes. Perhaps those olive feathers provide a better camouflage in amidst Finnish vegetation, or have come to signify virility in that part of the world. As evolutionary biologists Suzanne Gray and Jeffrey McKinnon describe in Trends in Ecology and Evolution review (pdf), differences in color are sometimes favored by natural selection—except, that is, when they’re not.

Often differences in color don’t have any function at all; they just happen to be. They emerge through what’s known as neutral evolution: mutations randomly spreading through populations. At times, this spread, this genetic drift, evenly distributes throughout the entire population, so the whole species changes together. Sometimes, though, the mutations confine themselves to different clusters within a species, like blobs of water cohering on a shower floor. 

One can imagine life evolving again and again, crashing on the rocks of time and circumstance, until finally it hit upon just the right mutation rate—one that eons later would produce organisms and species and ecosystems.

Given enough time and space, these processes can—at least theoretically, as experiments necessary for conclusive evidence would take millennia to run—generate new species. Such appears to be the case with greenish warblers living around the Tibetan plateau, who during the last 10,000 years have diverged into multiple, non-interbreeding populations, even though there are no geographic barriers separating them or evidence of local adaptations favored by natural selection. The raw material of life simply diversified. One became many, because that’s just what it does¹.

Through this lens, evolution is an intrinsically generative force, with diversity proceeding ineluctably from the very existence of mutation. And here one can step back for a moment, go all meta, and ask: Where does mutation itself come from? How did evolution, and evolvability, evolve?

It’s a question on the bleeding edge of theoretical biology, and one studied by Joanna Masel at the University of Arizona. Her work suggests that, several billion years ago, when life consisted of self-replicating chemical arrangements, a certain amount of mutation was useful: After all, it made adaptation possible, if merely at the level of organized molecules persisting in gradients of heat and chemistry. There couldn’t be too much of it, though. If there were, the very mechanics of replication would break down.

Molecular biologist Irene Chen of the University of California, Santa Barbara, has further illuminated that delicate balance. Her work posits that, as an information storage system, DNA was less error-prone than RNA, its single-stranded molecular forerunner and the key material of the so-called RNA world thought to have preceded life as we now know it.

So, then, one can imagine, early in Earth’s history, life evolving again and again, crashing on the rocks of time and circumstance, until finally it hit upon just the right mutation rate—one that eons later would produce organisms and species and ecosystems that reproduce themselves and persist across time and chancellor.

That’s the remarkable thing about life: It continues. It keeps going and growing. Barring catastrophic asteroid strikes, or possibly the exponential population growth of a certain bipedal, big-brained hominid, life on Earth maintains complexity, actually increases it, even as the natural tendency of systems is to become simpler. Clocks unwind, suns run down, individual lives end, the Universe itself heads towards its own cold, motionless death; such is the Second Law of Thermodynamics, inviolable and inescapable.

Yet so long as Earth’s sun shines and genetic mutations arise, evolution may maintain its own thermodynamic law. Black-capped chickadees and willow tits diverge. Life pushes back. 

Footnote 
1. To be sure, the concept of neutrally driven biodiversity isn’t universally accepted. There may be subtle, intrinsic advantages to diversification. An example comes from the models of James O’Dwyer, a theoretical ecologist at the University of Illinois: Simply by virtue of their novelty, new species may be intrinsically less vulnerable to pathogens that afflicted their evolutionary parents.

So, then, perhaps willow tits and black-capped chickadees evolved slightly different feather patterns because they provided some immediate, direct benefit; or maybe it happened just because, for no reason at all, really; or maybe there was a subtle benefit intrinsic to the process of variation itself; or maybe it was some combination of all three, varying by time and place.

So, it’s complicated. But whatever the complications, all these processes share something very fundamental: the emergence of variety over time as life’s essential property.

Brandon Keim (@9brandon) is a freelance journalist specializing in science, environment, and culture.

Ken Wilber - Integral Semiotics, Part 2: The Giga Glossary (Say What!?!)

I'm glad to see I am not the only blogger/reader (thank you Daniel Gustav Anderson) who has issues with Wilber's newest post on "integral semiotics," in which he argues for a "Giga glossary" (emphasis added):

What is required, at this point in evolution, is a “Giga glossary”—a comprehensive listing of the various phenomena (and hence various referents) found in each and every aspect of each and every dimension of the AQAL Matrix—listings of the phenomena found in all the quadrants, all the quadrivia, all the levels and Views, all the lines, all the states, and the types of existence and being-in-the-world that are presently arising. This would give us the Kosmic Address of every major phenomenon in the Kosmos (at least as now understood).

This is required? Really? By whom, and for what? 

Do we really need the "Kosmic Address" of "every major phenomenon in the Kosmos"? [For readers new to Wilberese, Kosmos is his term for the whole damn universe, from quarks to consciousness.]

"At this point in evolution," what it seems to me we need is a solution to climate change, a way to curb the obesity/diabetes epidemic that is no longer confined to the U.S. and Western Europe, free quality education for all, transparency in government, a viable P2P/Commons system to move us beyond capitalism, a cure for cancer, an end to the mass extinction of plants and animals . . . . I think you get my point.

Anderson has more philosophical issues with Wilber on this new proposal:

I find such categories as the possible, the emergent, and the novel to be of particular use; these are not yet accounted for here, insofar as the "Kosmic Address" described above concerns posited phenomena, the already realized, and not those presently articulating processes that are only now becoming. Further, I should hope that any competent semiotics would find ways to differentiate knowledge that is simply wrong (not just incomplete or partial but demonstrably false) from that which is merely incomplete, from that which is figurative (say, metaphoric or metonymic) and therefore not literally true but still bearing truth-value, and so on. (What counts as a phenomenon here?) I would like to know what the "Kosmic Address" of this concept of "Kosmic Address" is. Is it on Akashic Records lane?

Anderson suggests some other authors and books to read, so go see his recommendations (last paragraph). There is no doubt they are better than this, uh, new material.

*****

I kept reading Wilber's post after the section quoted above, which opens the article, but I became increasingly disheartened.

Wilber's whole project, from The Atman Project forward, seems to be an effort to explain his conception of God/Spirit/Ultimate Reality in a way that makes it seem more than faith in the validity of his subjective experience. In The Marriage of Sense and Soul, he outlines a kind of "reality testing," or "scientific method" for proving or disproving claims in the domain of spirituality. 

1. Instrumental injunction: The experiment, "If you want to know this, do this." The injunction might be, for example, if you want to experience nondual awareness, perform this meditation practice in just this way, for this length of time.
2. Direct apprehension: Here we get the experience, the apprehension, generated by the injunction. This step provides the data for the experiment.
3. Communal confirmation or rejection: At this final stage we compare our results with others who have performed the same injunction. We check our data against the data of others who have taken up that meditation practice for the prescribed length of time. [Wilber, 1998, The Marriage of Sense and Soul, p. 155-56]

The assumption (a false assumption, in my opinion) is that if enough people perform the experiment and get similar results, then the results point to some form of transcendent truth. In my opinion, this model is constructed, at least in part, to support his own conjectures around Spirit and Kosmos. Prior to this model, there was only "faith" or "belief," but with this Wilber proposed a way to test the reality claims of a given spiritual idea or injunction.

So let's use a real example. 

DMT (N,N-Dimethyltryptamine) is a popular and potent hallucinogen found in nature (and in human beings). Alongside LSD, mescaline, and psilocybin (to which it is structurally similar), it is probably one of the most widely studied hallucinogens in use. Strangely, and unlike many other hallucinogens, there is amazing commonality in the experiences of people who smoke (or use other inhalation methods of) DMT:

The subjective effects of a good lungful of DMT are usually very intense, with consciousness usually overwhelmed by visual imagery. With eyes closed this may take the form of extremely complex, dynamic, geometric patterns, changing rapidly. Such a dose of DMT may produce a visual pattern consisting of overlapping annular patterns of small rhomboid elements all in saturated hues of red, yellow, green and blue. Gracie & Zarkov [44] refer to this, or something similar, as "the chrysanthemum pattern." The pattern itself seems to be charged with a Portentous energy.

The state of consciousness characterized by amazing visual patterns seems to be a prelude to a more Profound state, which subjects report as contact with entities described as discarnate, nonhuman or alien. A very articulate account of the subjective effects of smoking DMT is given by Terence McKenna in his talk Tryptamine Hallucinogens and Consciousness [72], in which he recounts his contact with what he calls "elves."

Does the fact that many (most?) users of DMT experience something similar to this description mean, then, that "the chrysanthemum pattern" is real in some sense, or that "elves" and other "discarnate, nonhuman" entities exist someplace outside of our normal consciousness?

According to Wilber's model, the answer would seem to be yes.

However, these are drug-induced subjective experiences - there is nothing inherent in these experiences that requires them to have any reality outside of the drug state.

It's worth noting that Wilber, as late as 1998, was still writing and conceptualizing about the "Great Nest of Being," his reframing of the more traditional "Great Chain of Being."

In Integral Theory, the Great Nest of Being is not a Platonic given but, in large measure, is constructed of evolutionary Kosmic habits.

In essence, Wilber's is a teleological model of the universe.

A thing, process, or action is teleological when it is for the sake of an end, i.e., a telos or final cause. In general, it may be said that there are two types of final causes, which may be called intrinsic finality and extrinsic finality.[1]

• A thing or action has an extrinsic finality when it is for the sake of something external to itself. In a way, people exhibit extrinsic finality when they seek the happiness of a child. If the external thing had not existed that action would not display finality.
• A thing or action has an intrinsic finality when it is for none other than its own sake. For example, one might try to be happy simply for the sake of being happy, and not for the sake of anything outside of that.

Since the Novum Organum of Francis Bacon teleological explanations in science tend to be deliberately avoided because whether they are true or false is argued to be beyond the ability of human perception and understanding to judge.[2] Some disciplines, in particular within evolutionary biology, are still prone to use language that appears teleological when they describe natural tendencies towards certain end conditions, but these arguments can almost always be rephrased in non-teleological forms.

I have no real issue with teleological models, and even Thomas Nagel (see Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False, 2012) has recently been supportive of such models, as long as they do not include supernatural causes or beings. Nagel offers a real and valid metaphysics, "the question of what exists." Wilber offers "supernatural" causes, "that which is not subject to the laws of physics, or more figuratively, that which is said to exist above and beyond nature."

To my reading, Wilber's new "integral semiotics" is simply another attempt to justify and support his AQAL model. Granted, I am not dismissing AQAL as a basic orienting map, nor am I claiming that it's basic organizational premises are false.

What I am claiming is that the metaphysics upon which much of the spiritual element in integral theory is little more than intelligent design dressed in New Age clothing. And in that respect, Wilber's "integral semiotics" is simply another defense of that paradigm.

Michael Chorost - Where Thomas Nagel Went Wrong

Over at The Chronicle Review, Michael Chorost offers support for Thomas Nagel's recent book, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False, which was trashed by the evolutionist hierarchy.

Where Thomas Nagel Went Wrong

The philosopher's critique of evolution wasn't shocking. So why is he being raked over the coals?

May 13, 2013
By Michael Chorost 

Steve Brodner for The Chronicle Review
Thomas Nagel is a leading figure in philosophy, now enjoying the title of university professor at New York University, a testament to the scope and influence of his work. His 1974 essay "What Is It Like to Be a Bat?" has been read by legions of undergraduates, with its argument that the inner experience of a brain is truly knowable only to that brain. Since then he has published 11 books, on philosophy of mind, ethics, and epistemology.

But Nagel's academic golden years are less peaceful than he might have wished. His latest book, Mind and Cosmos (Oxford University Press, 2012), has been greeted by a storm of rebuttals, ripostes, and pure snark. "The shoddy reasoning of a once-great thinker," Steven Pinker tweeted. The Weekly Standard quoted the philosopher Daniel Dennett calling Nagel a member of a "retrograde gang" whose work "isn't worth anything—it's cute and it's clever and it's not worth a damn."

The critics have focused much of their ire on what Nagel calls "natural teleology," the hypothesis that the universe has an internal logic that inevitably drives matter from nonliving to living, from simple to complex, from chemistry to consciousness, from instinctual to intellectual.

This internal logic isn't God, Nagel is careful to say. It is not to be found in religion. Still, the critics haven't been mollified. According to orthodox Darwinism, nature has no goals, no direction, no inevitable outcomes. Jerry Coyne, an evolutionary biologist at the University of Chicago, is among those who took umbrage. When I asked him to comment for this article, he wrote, "Nagel is a teleologist, and although not an explicit creationist, his views are pretty much anti-science and not worth highlighting. However, that's The Chronicle's decision: If they want an article on astrology (which is the equivalent of what Nagel is saying), well, fine and good."

The odd thing is, however, that for all of this academic high dudgeon, there actually are scientists—respected ones, Nobel Prize-winning ones—who are saying exactly what Nagel said, and have been saying it for decades. Strangely enough, Nagel doesn't mention them. Neither have his critics. This whole imbroglio about the philosophy of science has left out the science.

Nagel didn't help his cause by (a) being a philosopher opining on science; (b) being alarmingly nice to intelligent-design theorists; and (c) writing in a convoluted style that made him sound unconvinced of his own ideas.

The Florida State University philosopher of science Michael Ruse, who has written extensively about arguments over Darwinian theory, says Nagel is a horse who broke into the zebra pen. Evolutionary biologists don't like it when philosophers try to tell them their business: "When you've got a leader of a professional field who comes in and says, as a philosopher, 'I want to tell you all that Darwinian evolutionary theory is full of it,' then of course it's a rather different kettle of fish."

Joan Roughgarden, an ecologist and evolutionary biologist at the ­Hawaii Institute of Marine Biology, agrees that evolutionary biologists can be nasty when crossed. "I mean, these guys are impervious to contrary evidence and alternative formulations," she says. "What we see in evolution is stasis—conceptual stasis, in my view—where people are ardently defending their formulations from the early 70s."

Nagel really got their noses out of joint by sympathizing with theorists of intelligent design. "They do not deserve the scorn with which they are commonly met," he wrote. "It is manifestly unfair." To be sure, he was not agreeing with them. He notes several times that he is an atheist and has no truck with supernatural gods. He views the ID crowd the way a broad-minded capitalist would sum up Marx: right in his critique, wrong in his solutions. But ID, he says, does contain criticisms of evolutionary theory that should be taken seriously.

Whatever the validity of this stance, its timing was certainly bad. The war between New Atheists and believers has become savage, with Richard Dawkins writing sentences like, "I have described atonement, the central doctrine of Christianity, as vicious, sadomasochistic, and repellent. We should also dismiss it as barking mad. ..." In that climate, saying anything nice at all about religion is a tactical error.

And Nagel is diffident about his ideas. Take this sentence, which packs four negatives into 25 words: "I am not confident that this Aristotelian idea of teleology without intention makes sense, but I do not at the moment see why it doesn't." Mind and Cosmos is full of such negatively phrased assertions. If you're going to make a controversial claim, it helps to do so positively. It also helps to enlist distinguished allies. Nagel has done nothing of the sort. Which is strange, because he has plenty of allies to choose from.

Natural teleology is unorthodox, but it has a long and honorable history. For example, in 1953 the evolutionary biologist Julian Huxley argued that it's in the nature of nature to get more advanced over time. "If we take a snapshot view, improvement eludes us," he wrote. "But as soon as we introduce time, we see trends of improvement."

More recently, Kevin Kelly, founding editor of Wired, made the case for teleology as clearly as could be in his book What Technology Wants: "Evolution ... has an inherent direction, shaped by the nature of matter and energy." That is, there may be laws of nature that push the universe toward the creation of life and mind. Not a supernatural god, but laws as basic and fundamental as those of thermodynamics. Robert Wright said much the same in Nonzero: The Logic of Human Destiny: "This book is a full-throated argument for destiny in the sense of direction." Those books prompted discussion among the literati but little backlash from evolutionary biologists. Ruse thinks that's because the authors are science writers, not scientists: "At a certain level, it's their job either to give the science or to put forward provocative hypotheses, and nobody takes it personally."

But highly regarded scientists have made similar arguments. "Life is almost bound to arise, in a molecular form not very different from its form on Earth," wrote Christian de Duve, a Nobel laureate in physiology or medicine, in 1995. Robert Hazen, a mineralogist and biogeologist at the Carnegie Institution for Science, struck a similar note in 2007: "With autotrophy, biochemistry is wired into the universe. The self-made cell emerges from geochemistry as inevitably as basalt or granite." Harold J. Morowitz, a biophysicist at George Mason University, argued that evolution has an arrow built into it: "We start with observations, and if the evolving cosmos has an observed direction, rejecting that view is clearly nonempirical. There need not necessarily be a knowable end point, but there may be an arrow."

Nagel discusses none of that work. He asserts only that evolution is directional, without making a case for it. That has left him open to a number of obvious rebuttals. The biologist H. Allen Orr, at the University of Rochester, pointed out that some species become less complex—parasites, for example, after learning how to steal resources from their hosts. And many species, such as sharks, have been happy to stay just the way they are for millions of years. Only one species—us—has bothered to reach sentience. "The point is," Orr wrote in The New York Review of Books, "that if nature has goals, it certainly seems to have many and consciousness would appear to be fairly far down on the list."

Indeed, biologists usually argue that when you do get progress, it came about by accident.

When you have millions of species taking random walks through the wilds of genetic variation and natural selection, some will, by the luck of the draw, become more complex and more capable. That is, when there is an overall increase in variance, some of the variants will be more complex and capable than their ancestors. Biologists say that such ascents in complexity happen "passively."

Yet some scientists think that increases in complexity also happen "actively," that is, driven by physical laws that directly favor increases in complexity. As a group, these scientists have no sympathy for intelligent design. However, they do see reasons to think that seen as a whole, life does go from simple to complex, from instinctual to intellectual. And they are asking if there are fundamental laws of nature that make it happen.

Perhaps the best known of these scientists is Stuart Kauffman, of the Santa Fe Institute, who argues that the universe gives us "order for free." Kauffman has spent decades on origin-of-life research, aiming to show that the transition from chemistry to metabolism is as inevitable as a ball rolling down a slope. Molecules on the early earth, he suggests, inevitably began to catalyze themselves in self-sustaining reactions ("autocatalytic networks"), converting energy and raw materials into increasingly complex structures that eventually crossed the boundary between nonliving and living. Nagel mentions his work once, briefly, in a footnote.

Kauffman has plenty of company. The paleontologist Simon Conway Morris, at the University of Cambridge, has argued that natural structures such as eyes, neurons, brains, and hands are so beneficial that they will get invented over and over again. They are, in effect, attractors in an abstract biological space that pull life in their direction. Contingency and catastrophe will delay them but cannot stop them. Conway Morris sees this as evidence that not only life but human life, and humanlike minds, will emerge naturally from the cosmos: "If we humans had not evolved, then something more or less identical would have emerged sooner or later."

Other biologists are proposing laws that would explain evolutionary ascent in fundamental terms. Daniel McShea and Robert Brandon, a biologist and a philosopher of science, respectively, at Duke University, have argued for what they call a "zero-force evolutionary law," which posits that diversity and complexity will necessarily increase even without environmental change. The chemist Addy Pross, at Ben-Gurion University of the Negev, in Israel, argues that life exhibits "dynamic kinetic stability," in which self-replicating systems become more stable through becoming more complex—and are therefore inherently driven to do so.

Still other scientists have asked how we could measure increases in complexity without being biased by our human-centric perspective. Robert Hazen, working with the Nobel Prize winner Jack Szostak, has proposed a metric he calls "functional information," which measures the number of functions and relationships an organism has relative to its environment. The Harvard astrophysicist Eric Chaisson has proposed measuring a quantity that he calls "energy-rate density": how much energy flows through one gram of a system per second. He argues that when he plots energy-rate density against the emergence of new species, the clear result is an overall increase in complexity over time.

While the jury is most definitely out on whether these proposed laws and measures are right or wrong (and if right, whether they are profound or trivial), this is a body of work that Nagel could have drawn upon in making his argument. He apparently felt it was acceptable to ignore the science. "Philosophy cannot generate such explanations," he wrote; "it can only point out the gaping lack of them." But there is no gaping lack of attempts to supply them. "He's done so little serious homework," says Michael Ruse. "He just dismisses origin-of-life studies without any indication that he's done any work on it whatsoever."

In short, Mind and Cosmos is not only negative but underpowered, as if Nagel had brought a knife to a shootout. (He declines to comment, telling me by e-mail, "I have a longstanding aversion to interviews.")

But Nagel's goal was valid: to point out that fundamental questions of origins, evolution, and intelligence remain unanswered, and to question whether current ways of thinking are up to the task. A really good book on this subject would need to be both scientific and philosophical: scientific to show what is known, philosophical to show how to go beyond what is known. (A better term might be "metascientific," that is, talking about the science and about how to make new sciences.)

The pieces of this book are scattered about the landscape, in a thousand scraps of ideas from biologists, physicists, physicians, chemists, mathematicians, journalists, public intellectuals, and philosophers. But no book has yet emerged that is mighty enough to shove aside the current order, persuading scientists and nonscientists alike, sparking new experiments, changing syllabi, rejiggering budget priorities, spawning new departments, and changing human language and ways of thought forever.On the Origin of Species did it in 1859. We await the next Darwin.


~ Michael Chorost is the author of Rebuilt: How Becoming Part Computer Made Me More Human (Houghton Mifflin, 2005) and World Wide Mind: The Coming Integration of Humanity, Machines, and the Internet (Free Press, 2011).

H. Allen Orr Reviews Thomas Nagel's "Mind and Cosmos"

At the New York Review of Books, H. Allen Orr reviews Thomas Nagel's Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False - he is thorough and finds, in the end, that Nagel too fully rejects materialism to be taken seriously. Rather, Nagel embraces a belief in the "tendency of the universe to aim for certain goals as it unfolds through time. Nagel believes that (currently unknown) teleological laws of nature might mean that life and consciousness arise with greater probability than would result from the known laws of physics, chemistry, and biology."

It is an interesting and thorough review.

Awaiting a New Darwin

FEBRUARY 7, 2013

H. Allen Orr

Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False
by Thomas Nagel
Oxford University Press, 130 pp., $24.95

Erin Pauwels Collection/Art Archive/Art Resource - ‘A Sun of the Nineteenth Century’; cartoon from Puck magazine showing Charles Darwin as a shining sun, chasing the clouds of religion and superstition from the sky, 1882

1.

The history of science is partly the history of an idea that is by now so familiar that it no longer astounds: the universe, including our own existence, can be explained by the interactions of little bits of matter. We scientists are in the business of discovering the laws that characterize this matter. We do so, to some extent at least, by a kind of reduction. The stuff of biology, for instance, can be reduced to chemistry and the stuff of chemistry can be reduced to physics.

Thomas Nagel has never been at ease with this view. Nagel, University Professor of Philosophy and Law at New York University, is one of our most distinguished philosophers. He is perhaps best known for his 1974 paper, “What Is It Like to Be a Bat?,” a modern classic in the philosophy of mind. In that paper, Nagel argued that reductionist, materialist accounts of the mind leave some things unexplained. And one of those things is what it would actually feel like to be, say, a bat, a creature that navigates its environment via the odd (to us) sense of echolocation. To Nagel, then, reductionist attempts to ground everything in matter fail partly for a reason that couldn’t be any nearer to us: subjective experience. While not denying that our conscious experiences have everything to do with brains, neurons, and matter, Nagel finds it hard to see how these experiences can be fully reduced with the conceptual tools of physical science.

In Mind and Cosmos, Nagel continues his attacks on reductionism. Though the book is brief its claims are big. Nagel insists that the mind-body problem “is not just a local problem” but “invades our understanding of the entire cosmos and its history.” If what he calls “materialist naturalism” or just “materialism” can’t explain consciousness, then it can’t fully account for life since consciousness is a feature of life. And if it can’t explain life, then it can’t fully account for the chemical and physical universe since life is a feature of that universe. Subjective experience is not, to Nagel, some detail that materialist science can hand-wave away. It’s a deal breaker. Nagel believes that any future science that grapples seriously with the mind-body problem will be one that is radically reconceived.

As Nagel makes clear in the subtitle of Mind and Cosmos, part of what he thinks must be reconceived is our reigning theory of evolutionary biology, neo-Darwinism. Neo-Darwinism maintains, or at least implies, that the origin and history of life can be explained by materialist means. Once the first life arose on earth, the fate of the resulting evolutionary lineage was, neo-Darwinists argued, shaped by a combination of random mutation and natural selection. Biological types that survive or reproduce better than others will ultimately replace those others. While natural selection ensures that species constantly adapt to the changing environments around them, the process has no foresight: natural selection responds only to the present environment and evolution cannot, therefore, be aiming for any goal. This view, Nagel tells us, is “almost certainly false.”


Before creationists grow too excited, it’s important to see what Nagel is not claiming. He is not claiming that life is six thousand years old, that it did not evolve, or that natural selection played no part in this evolution. He believes that life has a long evolutionary history and that natural selection had a part in it. And while he does believe that intelligent design creationists have asked some incisive questions, Nagel rejects their answers. Indeed he is an atheist. Instead Nagel’s view is that neo-Darwinism, and in fact the whole materialist view elaborated by science since the seventeenth century, is radically incomplete. The materialist laws of nature must, he says, be supplemented by something else if we are to fold ourselves and our minds fully into our science.

His leading contender for this something else is teleology, a tendency of the universe to aim for certain goals as it unfolds through time. Nagel believes that (currently unknown) teleological laws of nature might mean that life and consciousness arise with greater probability than would result from the known laws of physics, chemistry, and biology.

Scientists shouldn’t be shocked by Nagel’s claim that present science might not be up to cracking the mind-brain problem or that a profoundly different science might lie on the horizon. The history of science is filled with such surprising transformations. Nor should we dismiss Nagel’s claims merely because they originate from outside science, from a philosopher. Much the same thing happened when natural theology—the scientific attempt to discern God’s attributes from His biological handiwork—gave way to Darwinism.

It was the philosopher David Hume who began to dismantle important aspects of natural theology. In a devastating set of arguments, Hume identified grievous problems with the argument from design (which claims, roughly, that a designer must exist because organisms show intricate design). Hume was not, however, able to offer an alternative account for the apparent design in organisms. Darwin worked in Hume’s wake and finally provided the required missing theory, natural selection. Nagel, consciously or not, now aspires to play the part of Hume in the demise of neo-Darwinism. He has, he believes, identified serious shortcomings in neo-Darwinism. And while he suspects that teleological laws of nature may exist, he recognizes that he hasn’t provided anything like a full theory. He awaits his Darwin.

Mind and Cosmos is certainly provocative and it reflects the efforts of a fiercely independent mind. In important places, however, I believe that it is wrong. Because Nagel’s book sits at the intersection of philosophy and science it will surely attract the attention of both communities.1 As a biologist, I will perhaps inevitably focus on Nagel’s more scientific claims. But these are, it appears, the claims that are most responsible for the excitement over the book.

I begin by considering the reasons Nagel believes that materialist science, including neo-Darwinism, is false. I then turn to his alternative theory, teleology.

2.

Nagel believes that materialism confronts two classes of problems. One, which is new to Nagel’s thought, concerns purported empirical problems with neo-Darwinism. The other, which is more familiar to philosophers, is the alleged failure of materialism to explain consciousness and allied mental phenomena.

Nagel argues that there are purely “empirical reasons” to be skeptical about reductionism in biology and, in particular, about the plausibility of neo-Darwinism. Nagel’s claims here are so surprising that it’s best to quote them at length:

I would like to defend the untutored reaction of incredulity to the reductionist neo-Darwinian account of the origin and evolution of life. It is prima facie highly implausible that life as we know it is the result of a sequence of physical accidents together with the mechanism of natural selection. We are expected to abandon this naïve response, not in favor of a fully worked out physical/chemical explanation but in favor of an alternative that is really a schema for explanation, supported by some examples. What is lacking, to my knowledge, is a credible argument that the story has a nonnegligible probability of being true. There are two questions. First, given what is known about the chemical basis of biology and genetics, what is the likelihood that self-reproducing life forms should have come into existence spontaneously on the early earth, solely through the operation of the laws of physics and chemistry? The second question is about the sources of variation in the evolutionary process that was set in motion once life began: In the available geological time since the first life forms appeared on earth, what is the likelihood that, as a result of physical accident, a sequence of viable genetic mutations should have occurred that was sufficient to permit natural selection to produce the organisms that actually exist?

Nagel claims that both questions concern “highly specific events over a long historical period in the distant past, the available evidence is very indirect, and general assumptions have to play an important part.” He therefore concludes that “the available scientific evidence, in spite of the consensus of scientific opinion, does not in this matter rationally require us to subordinate the incredulity of common sense.”


This conclusion is remarkable in a couple ways. For one thing, there’s not much of an argument here. Instead Nagel’s conclusion rests largely on the strength of his intuition. His intuition recoils from the claimed plausibility of neo-Darwinism and that, it seems, is that. (Richard Dawkins has called this sort of move the argument from personal incredulity.) But plenty of scientific truths are counterintuitive (does anyone find it intuitive that we’re hurtling around the sun at 67,000 miles per hour?) and a scientific education is, to a considerable extent, an exercise in taming the authority of one’s intuition. Nagel never explains why his intuition should count for so much here.

As for his claim that evolutionary theory is somewhat schematic and that it concerns events that happened long ago, leaving indirect evidence, this is partly true of any historical science, including any alternative to neo-Darwinism, e.g., the one that Nagel himself suggests. In any case, a good part of the evidence for neo-Darwinism is not indirect but involves experiments in which evolutionary change is monitored in real time.2

More important, Nagel’s conclusions about evolution are almost certainly wrong. The origin of life is admittedly a hard problem and we don’t know exactly how the first self-replicating system arose. But big progress has been made. The discovery of so-called ribozymes in the 1980s plausibly cracked the main principled problem at the heart of the origin of life. Research on life’s origin had always faced a chicken and egg dilemma: DNA, our hereditary material, can’t replicate without the assistance of proteins, but one can’t get the required proteins unless they’re encoded by DNA. So how could the whole system get off the ground?

Answer: the first genetic material was probably RNA, not DNA. This might sound like a distinction without a difference but it isn’t. The point is that RNA molecules can both act as a hereditary material (as DNA does) and catalyze certain chemical reactions (as some proteins do), possibly including their own replication. (An RNAmolecule that can catalyze a reaction is called a ribozyme.) Consequently, many researchers into the origins of life now believe in an “RNA world,” in which early life on earth was RNA-based. “Physical accidents” were likely still required to produce the first RNA molecules, but we can now begin to see how these molecules might then self-replicate.

Nagel’s astonishment that a “sequence of viable genetic mutations” has been available to evolution over billions of years is also unfounded.3 His concern appears to be that evolution requires an unbroken chain of viable genetic variants that connect the first living creature to, say, human beings. How could nature ensure that a viable mutation was always available to evolution? The answer is that it didn’t. That’s why species go extinct. Indeed that’s what extinction is. The world changes and a species can’t find a mutation fast enough to let it live. Extinction is the norm in evolution: the vast majority of all species have gone extinct. Nagel has, I think, been led astray by a big survivorship bias: the evolutionary lineage that led to us always found a viable mutation, ergo one must, it seems, always be available. Tyrannosaurus rex would presumably be less impressed by nature’s munificence.4

3.

While Nagel’s worries about neo-Darwinism are misplaced, he’s on somewhat firmer (or at least more familiar) ground when he turns to mental phenomena like consciousness. These are, after all, separate problems. A science might explain the evolution of life but leave consciousness—the subjective experience of the saltiness of popcorn, the shock of cold water, or the sting of pain—unaccounted for. Consciousness is Nagel’s big problem:

Consciousness is the most conspicuous obstacle to a comprehensive naturalism that relies only on the resources of physical science. The existence of consciousness seems to imply that the physical description of the universe, in spite of its richness and explanatory power, is only part of the truth, and that the natural order is far less austere than it would be if physics and chemistry accounted for everything.

Nagel’s story here starts, as it must, with Descartes. As Nagel writes, Descartes posited that matter and mind are “both fully real and irreducibly distinct, though they interact.” Given this, science was, from the outset, concerned solely with matter; mind belonged to a different domain. While scientists happily toiled under Cartesian dualism, giving rise to a recognizably modern science, philosophers often demurred. Instead, thinkers like Berkeley favored various forms of idealism, which maintains that nature is at bottom mind. Under idealism, then, any reductionist program would be in the business of collapsing matter to mind.

Nagel argues that as a result of a rapid shift whose causes are unclear, these idealist philosophies were “largely displaced in later twentieth-century analytic philosophy by attempts at unification in the opposite direction, starting from the physical.” This approach likely seems natural to most of us. But we live with a tension. Though the materialist program of reducing mind to matter would appear the properly “scientific” approach, we haven’t the slightest idea how it would work. And it’s not for lack of trying. Philosophers have, Nagel reminds us, attempted many ways of tying mind to matter: conceptual behaviorism, physical identity theory, causal behaviorism, and functionalism, to name a few. To Nagel all these approaches have failed “for the same old reason”:

Even with the brain added to the picture, they clearly leave out something essential, without which there would be no mind. And what they leave out is just what was deliberately left out of the physical world by Descartes and Galileo in order to form the modern concept of the physical, namely, subjective appearances.

Nagel is deeply skeptical that any species of materialist reductionism can work. Instead, he concludes, progress on consciousness will require an intellectual revolution at least as radical as Einstein’s theory of relativity.

Nagel’s chapter on consciousness is a concise and critical survey of a literature that is both vast and fascinating. He further extends his survey to other mental phenomena, including reason and value, that he also finds recalcitrant to materialism. (Nagel concludes that the existence of objective moral truths is incompatible with materialist evolutionary theory; because he is sure that moral truths exist, he again concludes that evolutionary theory is incomplete.)

Nagel concedes that many philosophers do not share his skepticism about the plausibility of reducing mind to matter. And I can assure readers that most scientists don’t. I, however, share Nagel’s sense of mystery here. Brains and neurons obviously have everything to do with consciousness but how such mereobjects can give rise to the eerily different phenomenon of subjective experience seems utterly incomprehensible.

Despite this, I can’t go so far as to conclude that mind poses some insurmountable barrier to materialism. There are two reasons. The first is, frankly, more a sociological observation than an actual argument. Science has, since the seventeenth century, proved remarkably adept at incorporating initially alien ideas (like electromagnetic fields) into its thinking. Yet most people, apparently including Nagel, find the resulting science sufficiently materialist. The unusual way in which physicists understand the weirdness of quantum mechanics might be especially instructive as a crude template for how the consciousness story could play out. Physicists describe quantum mechanics by writing equations. The fact that no one, including them, can quite intuit the meaning of these equations is often deemed beside the point. The solution is the equation. One can imagine a similar course for consciousness research: the solution is X, whether you can intuit X or not. Indeed the fact that you can’t intuit X might say more about you than it does about consciousness.

And this brings me to the second reason. For there might be perfectly good reasons why you can’t imagine a solution to the problem of consciousness. As the philosopher Colin McGinn has emphasized, your very inability to imagine a solution might reflect your cognitive limitations as an evolved creature. The point is that we have no reason to believe that we, as organisms whose brains are evolved and finite, can fathom the answer to every question that we can ask. All other species have cognitive limitations, why not us? So even if matter does give rise to mind, we might not be able to understand how.

To McGinn, then, the mysteriousness of consciousness may not be so much a challenge to neo-Darwinism as a result of it. Nagel obviously draws the opposite conclusion. But the availability of both conclusions gives pause.

4.

Given the problems that Nagel has with materialism, the obvious question is, What’s the alternative? In the most provocative part of Mind and Cosmos, he suggests one, teleology. While we often associate teleology with a God-like mind—events occur because an agent wills them as means to an end—Nagel finds theism unattractive. But he insists that materialism and theism do not exhaust the possibilities.

Instead he proposes a special species of teleology that he calls natural teleology. Natural teleology doesn’t depend on any agent’s intentions; it’s just the way the world is. There are teleological laws of nature that we don’t yet know about and they bias the unfolding of the universe in certain desirable directions, including the formation of complex organisms and consciousness. The existence of teleological laws means that certain physical outcomes “have a significantly higher probability than is entailed by the laws of physics alone—simply because they are on the path toward a certain outcome.”

Nagel intends natural teleology to be, among other things, a biological theory. It would explain not only the “appearance of physical organisms” but the “development of consciousness and ultimately of reason in those organisms.” Teleology would also provide an “account of the existence of the biological possibilities on which natural selection can operate.”

Nagel concedes that his new theory isn’t fully fleshed out. He hopes merely to sketch the outlines of a plausible alternative to materialism. It’s unfortunate, though, that Mind and Cosmos is too brief to allow consideration of problems that attend natural teleology. For it seems to me that there are some, especially where the view confronts biology.

Darwin himself wrestled with attempts to reconcile his theory with teleology and concluded, reluctantly, that it seemed implausible. While Darwin published almost nothing on such philosophical matters they loom large in his correspondence, particularly with Asa Gray, an American champion of evolution and a Christian. Gray, like Nagel, wanted to believe that, while Darwin had identified an important force in the history of life, nature also features teleology. In particular, Gray suggested that the variation provided by nature to natural selection biases the process in desirable directions.

Darwin, though sometimes vacillating, argued that Gray’s reconciliation was implausible. Exercising his uncanny ability to discern deep truths in prosaic facts—in this case the artificial selection of a pigeon breed by a few fanciers—Darwin wrote Gray:

But I grieve to say that I cannot honestly go as far as you do about Design…. You lead me to infer that you believe “that variation has been led along certain beneficial lines”.—I cannot believe this; & I think you would have to believe, that the tail of the Fan-tail was led to vary in the number &direction of its feathers in order to gratify the caprice of a few men.5

Here’s another problem. Nagel’s teleological biology is heavily human-centric or at least animal-centric. Organisms, it seems, are in the business of secreting sentience, reason, and values. Real biology looks little like this and, from the outset, must face the staggering facts of organismal diversity. There are millions of species of fungi and bacteria and nearly 300,000 species of flowering plants. None of these groups is sentient and each is spectacularly successful. Indeed mindless species outnumber we sentient ones by any sensible measure (biomass, number of individuals, or number of species; there are only about 5,500 species of mammals). More fundamentally, each of these species is every bit as much the end product of evolution as we are. The point is that, if nature has goals, it certainly seems to have many and consciousness would appear to be fairly far down on the list.

Similarly, Nagel’s teleological biology is run through with talk about the “higher forms of organization toward which nature tends” and progress toward “more complex systems.” Again, real biology looks little like this. The history of evolutionary lineages is replete with reversals, which often move from greater complexity to less. A lineage will evolve a complex feature (an eye, for example) that later gets dismantled, evolutionarily deconstructed after the species moves into a new environment (dark caves, say). Parasites often begin as “normal” complicated organisms and then lose evolutionarily many of their complex traits after taking up their new parasitic way of life. Such reversals are easily explained under Darwinism but less so under teleology. If nature is trying to get somewhere, why does it keep changing its mind about the destination?6

I’ll be the first to admit that these problems may not be fatal. But they represent the sorts of awkward facts that occur immediately to any biologist. Minimally, they pose serious challenges to teleology, challenges that deserve, but do not receive, consideration in Mind and Cosmos. 

5.

I will also be the first to admit that we cannot rule out the formal possibility of teleology in nature. It could turn out that teleological laws affect how the universe unfolds through time. While I suspect some might regard such heterodoxy as a crime against science, Nagel is right that there’s nothing intrinsically unscientific about teleology. If that’s the way nature is, that’s the way it is, and we scientists would need to get on with the business of characterizing these surprising laws. Teleological science is, in fact, more than imaginable. It’s actual, at least historically. Aristotelian science, with its concern for final cause, was thoroughly teleological. And the biological tradition that Darwinism displaced, natural theology, also featured a good deal of teleological thinking.

The question, then, is not whether teleology is formally compatible with the practice of science. The question is whether the practice of science leads to taking teleology seriously. Nagel may find this question unfair. He is, he says, engaging in a “philosophical task,” not the “internal pursuit of science.” But it seems clear that he is doing more than this. He’s emphasizing purported “empirical reasons” for finding neo-Darwinism “almost certainly false” and he’s suggesting the existence of new scientific laws. These represent moves, however halting, into science proper. But science, finally, isn’t about defining the space of all formally possible explanations of nature. It’s about inference to the most likely hypothesis. And on these grounds there’s simply no comparison between neo-Darwinism (for which there is overwhelming evidence) and natural teleology (for which there is none). While one might complain that it’s unfair to stack up the empirical successes of neo-Darwinism with those of a new theory, this, again, gets the history wrong. Teleology is the traditional view; neo-Darwinism is the new kid on the block.

None of this is to suggest that evolutionary biology will not, someday, change radically. Of course it might; any science might. Nor is it to suggest that materialism represents some final unassailable view and that teleology or, for that matter, theism will inevitably be spoken of in the past tense by many scientists. It is to say that the way to any such alternative view will have to acknowledge the full powers of present science. I cannot conclude that Mind and Cosmos does this.

NOTES:
1. Nagel’s work has long attracted the attention of both philosophers and scientists. Indeed the careful reader will notice that I’m mentioned in his new book as a scientist-participant in a workshop that he organized on some of the topics covered in the book; many of the other participants were philosophers. ↩
2. The field of “experimental evolution” is concerned with watching evolution as it occurs. Because of their short generation time, microbes are the focus of much of this work. ↩
3. While I’ve heard this concern before, I must admit that I think I only now understand it. ↩
4. This is not to say that adaptation is rare or that natural selection doesn’t modify the DNA sequences of species. Even species that ultimately go extinct have experienced many previous bouts of successful adaptation. ↩
5. November 26, 1860; see www.darwinproject.ac.uk/entry-2998. Historians of science do not all agree that Darwin wholly banished teleology from his thinking; see the exchange between James G. Lennox (1993, 1994) and Michael T. Ghiselin (1994) in Biology and Philosophy. ↩
6. It’s true that organisms are on average more complex now than they were three billion years ago. But as biologists have long recognized, this doesn’t require any inexorable bias toward complexity. If life starts from a floor of zero complexity, it can on average only get more complicated. ↩