Lamarckism Revisited

  The concept that traits acquired during an individual's lifetime can be passed on to offspring and therefore affect evolution—a theory most associated with the French scientist Jean-Baptiste Lamarck (1744-1829)—was relegated to the dust bin by the advent of Darwinism.  After Darwin, a new orthodoxy prevailed for more than a century.  In present-day terminology, it held that only traits already embedded in genes are passed on, and evolution occurs exclusively by natural selection of mutations in the genome.  Such mutations are purely random events, caused by errors in DNA transcription or by environmental factors.  Any suggestion of "directed" mutations—beneficial, nonrandom changes in the genome provoked by an organism in response to specific environmental challenges—was decried.  Further, the notion that changes in and inheritance of traits could occur through other than genetic means was anathema.

  That orthodox Darwinian viewpoint has been challenged in the past 30 years or so.  Modern studies have shown that directed, nonrandom genomic mutations can occur; that acquired non-genomic attributes can be inherited; and that both are subject to natural selection in the same way as are random genomic mutations.  These new insights and much else are discussed in a remarkable, but lengthy and hard-to-read book by Eva Jablonka and Marion J. Lamb, Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral and Symbolic Variation in the History of Life.

  I will skip over Jablonka-Lamb's first dimension, genetics, for it is the Darwinian dimension, with which I assume you are familiar.  The second dimension, epigenetics, is the most astounding to me.  It turns out that molecular "markers" can attach themselves to the genome as a result of environmental impact or stress.  They do not change the genome, but can turn genes on and off, thus changing the expression of an individual's genetic traits.  What is surprising is that these epigenetic factors can be passed on to offspring.

  The earliest-discovered and most common epigenetic marker is methylation of DNA.  Small methyl (CH₃) groups can become attached to bases in the DNA sequence because of environmental influences and stress, but they do not change the DNA other than by turning genes on or off.  Remarkably, the methylation remains in daughter cells after cell division.  Even more remarkably, when methylation affects sperm or egg cells, it is inherited by an embryo and thus passed on to the next generation.  To quote from Jablonka-Lamb:

"[B]ecause it provides an additional source of variation, evolution can occur through the epigenetic dimension of heredity even if nothing is happening in the genetic dimension.  But it means more than this.  Epigenetic variations are generated at a higher rate than genetic ones, especially in changed environmental conditions, and several epigenetic variations may occur at the same time.  Furthermore, they may not be blind to function, because changes in epigenetic marks probably occur preferentially on genes that are induced to be active by new conditions.  This does not mean that all induced changes are adaptive, but it does increase the chances that a variation will be beneficial.  The combination of these two properties—a high rate of generation and a good chance of being appropriate—means that adaptation through the selection of epigenetic variants may be quite rapid compared with adaptation through genetic change."

This one astonishing paragraph was to me worth the price of the book.

  Less compelling to me, but still impressive, are Jablonka and Lamb's asserted third and fourth dimensions of evolution—behavioral and symbolic.  If I understand these dimensions correctly, they overlap with and extend what the British evolutionary biologist Richard Dawkins called "memes"—an analog of genes.  Just as a gene carries information about biological traits, a meme carries information about socio-cultural ideas, symbols, and practices that are passed from generation to generation but not necessarily to direct offspring.  That many memes are acquired under the influence of the environment and unrelated individuals, and propagated by social interaction rather than genetics, doesn't sound extraordinary—we know that species, especially Homo sapiens, pass on a vast repertoire of behaviors derived from their environment and social groupings.  More startling, however, is evidence Jablonka and Lamb cite indicating that acquired memes may also be inherited through bio-chemical means; for example, a mother's particular food preferences have been shown to be reproduced in her offspring through placental affects on the fetus.  The important point Jablonka and Lamb make is that memes as well as genes are subject to evolutionary selection: those that are advantageous for survival will persist, those that aren't will vanish.

  The focus of the Jablonka-Lamb book is therefore on information transmission as the basis of evolution, not only the biological information of the genome and its epigenetic markers, but also the behavioral and symbolic information of cultures. 

"All four ways of transmitting information introduce, to different degrees and in different ways, instructive mechanisms into evolution.  All shape evolutionary change. …  As molecular biology uncovers more and more about epigenetic and genetic inheritance, and as behavioral studies show how much information is passed on to others by nongenetic means, evolutionary biologists will have to abandon their present concept of heredity, which was fashioned in the early days of genetics."

For those of us who have been raised in the pure-genetics tradition, this is a big gob to swallow.  We were taught to ignore Lamarck and to disdain the USSR's ideologically motivated Lysenko;  now, it seems, some of their ideas may turn out to have merit.

We and I

  I ended Quietly Doing One's Duty by wondering whether the ethic implied in its title might have become anachronistic—whether individual devotion to the collective good is passé.  In more and more arenas, we have adopted a market-oriented approach to communal objectives, asserting that they are best gained from the random interactions of myriad individuals, all selfishly seeking their own goals.  This is Malthusianism and social Darwinism redux, holding that the survival of the fittest in human affairs is an inviolable natural law leading to the benefit of society as a whole.

  Perhaps no societal question is more fraught than the relationship between the collective and the individual.  The pendulum of thought and power constantly swings between the two.  Daniel T. Rodgers, professor of history at Princeton, argues in his 2012 book The Age of Fracture that the last part of the 20^th century involved such a swing, a massive one from the collective to the individual.  While I found the book at times tedious and rambling, I think its underlying thesis is correct, and therefore felt it was worth reading.  Consider just the following issues, some of which are thoroughly discussed in the book:

• The "Greatest Generation" celebrated by Tom Brokaw, which ennobled self-sacrifice for the good of all, morphed into Tom Wolfe's "Me Generation": the baby boomers who despoiled the commons for their own advantage.   In the process, John Kennedy's famous 1961 Inaugural plea, "Ask what you can do for your country," segued into Ivan Boesky's infamous 1986 dictum, "Greed is healthy," shamefully enunciated at a UC Berkeley business-school commencement,

• The top-down Keynesian macroeconomics that advocates economic regulation for the good of the commonwealth—a view widely held in the wake of the Great Depression—was displaced by a bottom-up microeconomics interested only in countless individuals and firms responding to price signals in satisfaction of their own wants.  We have put Adam Smith's invisible hand of the marketplace on steroids, although he was concerned with a measured trade in goods, not fevered gambling on derivative financial instruments.  Any measure of control of the economy is widely scorned by those who wield the greatest power in it, those who glorify Schumpeter's ideal of "creative destruction" in unrestrained capitalism (as long, perhaps, as it is not their own domains being destroyed).

• The conviction that government is an active partner providing goods and services that the market cannot provide easily or at all—safety nets, infrastructure, education, defense, environmental protection—has come into disrepute by much more than a fringe.  Many consider government as an outright enemy, at best a hindrance, which gets in the way of an efficient marketplace and sops up resources better left in the hands of individuals.  The safety nets of Social Security and Medicare?  Switch them over to competition in the private sector.  Medical care for all?  Let the devil (or the emergency room) take the hindmost.  Welfare?  Consign it to private charity.  Infrastructure?  Let it crumble until a catastrophe dictates repair, or sell it off to private enterprise.  Education?  Issue vouchers for it that can be used at private schools, which will vie for them, or outsource it to competing charter schools.  Defense?  No citizen's army is needed; let its burden be assumed by the least advantaged, and outsource as much as possible to the efficiencies of mercenary market participants.  Environmental protection?  Let it function most cost-effectively in a marketplace where licenses to pollute are traded. 

• The ideal of E Pluribus Unum—Out of Many, One—with all of the One subscribing to a core ethos, has dissolved into a plethora of contentious, often-hostile special-interest groups, each congealed into a power bloc.  The pendulum has swung from the stultifying conformity of the mid-20^th century to a veneration of unconstrained individualism.  Hyphenated Americans fixate more on the adjective that modifies the word "American" than on "American."  It is the market again at work, this time in the political arena, where blocs striving against one another are thought to yield a greater common good than blocs cooperating or subsuming their own agendas to a common national purpose.

  This is the Age of Fracture about which Rodgers writes. There seems to be no sphere in which the market's invisible hand is not seen as a solution.  Of course, not all obeisance to the marketplace is bad per se; but the constant hosannas to its god-like powers are.  As Rodgers puts it,  "The nation disaggregated into a constellation of private acts"—those acts to be mediated for the benefit of the nation by the magic of the market. 

  In the face of such fissuring, is it any wonder that our ability to govern ourselves has plummeted?  Legislators, selfishly concentrating on their re-electability, dare not depart from the schismatic blocs to which they are beholden, dare not give priority to the commonweal.  Compromise is anathema.  Lobbyists, who seem to be more numerous than legislators, re-enforce loyalty to blocs with massive amounts of money.  The Supreme Court has ruled that money—any amount of it—is a vicar for free speech in the marketplace of ideas.  The result is a system of governance stalemated among immovable cabals.  

  To return to the question with which I opened: Is individual devotion to the collective good passé?  Perhaps temporarily, but not in the long run.  The pendulum will inevitably swing back as the damages caused by extreme individualism become more apparent to all.  The real question is, can the pendulum's oscillations be dampened so that commitment to the community and to the individual can coexist in a balanced equilibrium?

Mind and Matter

  An unfavorable but thought-provoking review earlier this month in The New York Review of Books introduced me to both the renowned NYU philosopher Thomas Nagel and his recent book, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False.  Even if the review had been favorable, the subtitle of the book alone would normally have caused me to shrug and move on to other things.  Those who follow this blog know I'm not patient with philosophical prattlings about the nature of the universe.  (See my posting Whence the Universe.)  Nagel's book seemed to be of that ilk.

  But I was arrested by a summary of Nagel's perspective given by the reviewer:

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. 

That reminded me of my son David's panpsychism, which I mentioned last month in Philosophy, Schmilosophy!  He believes that all of creation is permeated with consciousness and develops with an ethereal, beneficent purpose.  I embrace the polar-opposite outlook, that the cosmos evolves purely randomly, without any transcendental goal.  I decided to read Nagel's book to see if it might shed further light on this dichotomy.

***

  First off, and a little disconcertingly, Nagel acknowledges his debt to creationists for having kept alive the possibility of an alternative to materialistic Darwinism.  He in fact joins them in three contentions: (1) the probability of an accidental formation of self-reproducing living matter from inanimate matter is infinitesimal; (2) even if living matter  did form randomly, against all odds, there hasn't been enough geologic time for life with the biological and physical complexity of humans to have evolved through random mutations alone; (3) consciousness is so incomprehensible under a materialistic approach that a move beyond Darwinism is necessary.  Unlike creationists, however, Nagel doesn't come to a theistic conclusion—an Intelligent Designer—from these assertions.  As an atheist, he instead looks for a naturalistic addition to evolutionary theory.

  Nagel devotes most of his book to the problem of consciousness.  Materialists already have extensive neuroscientific evidence supporting their hope that consciousness will eventually be explained as activity of the brain cells—mind reduced to matter—but even they admit to currently being at a loss for a complete schema.  Nagel contends, as in his subtitle, that such a materialist monism is almost certainly a false trail.  He also dismisses both the dualism of Descartes, which almost entirely separates mind and matter; and the reductionism of such idealist philosophers as Bishop Berkeley, who advance a different sort of monism, that matter is reducible to mind, having no reality other than as a mental construction.  Nagel instead adheres to a philosophical concept called neutral monism—that the elementary stuff of which the universe is made is not purely physical or purely mental, but indivisibly both, neither reducing to the other.

  Nagel's case for neutral monism is intuitive, expressed in assertions like the following, which I have spliced together from several pages of one of his chapters: 

Organisms such as ourselves do not just happen to be conscious; therefore no explanation of the physical character of those organisms can be adequate which is not also an explanation of their mental character. … A naturalistic expansion of evolutionary theory to account for consciousness … would have to offer some account of why the appearance of conscious organisms, and not merely of behaviorally complex organisms, was likely. … It is not enough to say, "Something had to happen, so why not this?"  [Boldface is mine.]

I have boldfaced the word "likely" in this passage to emphasize Nagel's predicate of teleology: he calls for a naturalistic explanation in which evolution is systematically driven toward the development of conscious life rather than just life itself. 

  What could such a bias consist of?  Nagel discards panpsychism—that consciousness permeates the universe, making the evolution of conscious creatures likely.  He opts instead for emergent consciousness—that there are as yet undiscovered natural laws which, together with the laws of biology, chemistry and physics we already know, lead to consciousness in sufficiently complex organisms.

  Nagel offers no clue about what these additional laws might be, only asserting that they must exist in order to explain consciousness and such ancillary concepts as cognition and value-based behavior.  But how can one's skepticism not be stoked by the absence of any elaboration?  And, if his brand of neutral monism is truly neutral, driving evolution toward consciousness in tandem with physical complexity, why wouldn't some complex plants on Earth have developed signs of consciousness as well as many complex animals? Indeed, why does Nagel's teleology strike one as implausibly anthropocentric?

  Despite my skepticism, I am not so negative about Nagel's speculations as I was about the metaphysical pap I decried in Whence the Universe, where I discussed the book Why does the World Exist?  Much in that book consists of wild imaginings which seemed to me to have no gloss of rational thought.  Nagel, on the other hand, rationally postulates a missing element—unknown non-materialistic laws—to fill out our understanding of consciousness, and tries to thrash out the consequences of such a postulate.

  Yet this postulate smacks of others that have been introduced into science in attempts to accommodate the mysterious—for example, phlogiston to explain the release of heat from burning material and the luminiferous æther to explain how light could travel through a vacuum.  Scientists eventually discovered how to remove those intuitive but false suppositions.  Given Nagel's inability, other than through reference to his intuition, to adduce any evidence to support his neutral monism, materialist monists like myself will continue to expect and await an explanation of consciousness based solely on biology, chemistry and physics.

***

  Nagel's book neither changed my conception of the universe nor further illuminated David's for me.  More to the point, I think Nagel presumes on a bygone relationship of philosophy to science.  Many centuries ago, when science was still called "natural philosophy," the ruminations of philosophers about the nature of the universe still had an influence on science's development, if only—as do Nagel's—by raising more questions than they answered.  Since then, that influence has continually diminished, to the point where it is now pretty much nil.  Nagel's effort to turn back the clock is quixotic.

Eusociality

  Certain invertebrate species such as ants, in which individuals subordinate their own needs to those of the group, are said to be eusocial.  The term has also been applied more loosely to some vertebrate species, particularly Homo sapiens.  Unlike ants, though, humans act selfishly for their own survival and reproductive benefit as well as altruistically for the benefit of groups to which they belong.

  Eusociality is the thought-provoking subject of my book club's latest selection, The Social Conquest of Earth by E. O. Wilson of Harvard University.  Wilson is one of the world's leading biologists and probably its leading entomologist.  His lifelong study of eusociality in insect colonies led him to study it in humans, in order to explain how we came to dominate the biosphere.  In describing the difference between eusociality in ants and humans, Wilson wryly observed that "Karl Marx was right, socialism works, it is just that he had the wrong species."

  A warning before I proceed: Wilson is one of the originators and a strong proponent of a controversial sociobiological theory which asserts that eusociality is dependent on evolution of groups as groups, a level of evolution above that of individuals.  As did Darwin with ant and bee colonies, he sees the group as a macro-organism, subject to forces of natural selection.  It is a top-down theory, in which the group selectively chooses as members those who express a set of innate altruistic traits favoring the group's success in competition with other groups.  Wilson is an equally strong opponent of an alternative evolutionary theory called kin selection, a bottom-up theory, which posits that altruistic behavior in groups evolves only because individuals in the groups already share family genes, and accordingly at times act selflessly to assure the perpetuation of their genes in others if not in themselves. 

  The argument literally rages.  Evolutionists Jerry Coyne of the University of Chicago and Richard Dawkins of Oxford have unsparingly attacked Wilson [1,2].  In the remainder of this posting, however, I'll summarize some key points of Wilson's book as well as I can—it is not always easy for a layperson to follow.

****

  The development of eusociality is quite rare.  Of the many millions of invertebrate species, only a score or so have independently achieved it, the remaining species competing largely at the level of individuals rather than groups.  (Think flies and ants.)  Among vertebrates, eusociality is even rarer, having occurred in just a handful of species, including Homo sapiens.  Its appearance in ants has led to their dominance over the insect world, in humans to their dominance over the world at large.

  What is amazing, Wilson maintains, is that eusociality has occurred at all, for the evolutionary maze that leads to it is so extensive and full of twists and dead ends, that for any species to wend its way through the maze is something of a miracle.  After all, eusociality must get its rudimentary start in a species where the rule is selfish natural selection at the individual level, and selflessness/altruism the exception.  Still, ants and their precursors negotiated the maze successfully over many millions of years, as did the line of hominins leading to Homo sapiens in a somewhat shorter time.  Wilson describes the process as involving a long sequence of small evolutionary pre-adaptations over hundreds of thousands to millions of years, leading to a tipping point where the random mutation of as little as a single gene in an individual could start the final conversion to full eusociality.

  Eusociality in humans is of course very far from the extreme of the genetically homogeneous, fixed-caste behavior of ants, yet goes much farther than the social behavior of other vertebrates.  A critical competitive advantage of humans vis-à-vis other vertebrates is that they build defensible, multigenerational, task-allocating cooperatives to which members may have no genetic kinship.  Each community, Wilson says, selects for inclusion individuals who express a desirable subset of altruistic behaviors, most of which were already deeply ensconced in the human genome at the time Homo sapiens emigrated from Africa some 60,000 years ago.  The chosen subset reflects the evolved culture of the group.

  The tension in mankind between the opposing forces of individual/selfish natural selection and group/selfless selection is complex.  Genetic evolution in the former arises from competition between members of a group, in the latter from competition between groups. The two types of competition point evolutionarily in opposite directions because one requires selfishness and the other altruism.  Homo sapiens maintains a tenuous balance between the two because of what Wilson calls the "iron rule": selfish individuals beat altruistic ones, yet groups of altruists beat groups of selfish individuals. 

  The relationship between genes and culture in eusocial groups is also a critical element in group evolution, Wilson asserts, and equally complex.  In building a culture, genes make available not just one trait as opposed to another, but patterns of traits that together define the culture.  The expression of multiple traits is plastic, allowing a society to choose an ensemble from many available combinations, the choices differing among societies.  Wilson contends that the degree of plasticity itself is subject to evolution by natural selection.  These concepts add another perspective to the nature/nurture question, very different, e.g., from one presented in a book by psychologist Bruce Hood that I discussed in my posting The Self.

   A final, quintessential point.  For Wilson, the indispensible requirement for the development of human eusociality—without which group selection could not have proceeded—is the primitively evolved instinct to form tribes.  He says that people feel they must belong to tribes for their existential sense of identity, security and well-being.  Eons ago they were small bands that hunted and gathered together, built encampments, and defended each other and their young.  Today, individuals join many interlocking tribes—city, country, religion, even sports teams—each commanding loyalty, communal effort, and competition with other tribes of the same genre.  In  this sense group evolution is bilateral: groups select individuals based on group needs, and individuals choose groups based on their own needs.

  As evidence that the tribal instinct is extremely deeply embedded in the species, Wilson cites a recent experiment showing that, when pictures of out-group people are flashed in front of experimental subjects, their amygdalas—their brains' centers of fear and anger—activate so quickly and subtly that the conscious centers of their brains are unaware of the response.  Other experiments revealed that even when experimenters created groups at random, inter-group prejudice quickly established itself, subjects always ranking the out-group below the in-group.

****

  Many of the ideas in Wilson's book are indeed controversial, and at times I found them alternately too detailed or too sketchy.  Still, it is a feast for thought, which has forced me to reconsider some previous musings in this blog.

  First, the deep-seated need for tribal association undermines my conjecture in a recent posting, where I discussed tribalism/clannishness and what I called their antithesis, "anticlans."  I suggested that tribalism might be ready for obsolescence in our modern, globally hyper-connected society.  I was of course out of my depth, and therefore took to wild speculation.  I asked whether the modern obsessive inclusiveness of social-networking activities could lead to a widespread "we're all in it together" anticlan behavior, which over the long run could evolutionarily trump the exclusionary, "we vs. them" behavior of clans. 

  I think Wilson would answer my question with a definitive "No."  He spends just one paragraph of his 350-page book noting that the increasing interconnection of people worldwide through the internet and globalization weakens the relevance of ethnicity, locality, and nationhood as sources of identification.  Tribes may wax and wane and sources of tribal identification may shift, but Wilson would hold that tribalism itself will survive, overwhelming anticlan behavior just as it has always defeated less-tribal species.  Bummer.

  Second, the almost-impossibility of negotiating the evolutionary labyrinth to yield a species like Homo sapiens sheds further light on my posting on the search for extra-terrestrial intelligence (SETI).  In a catalog of obstacles to the success of SETI, I listed the rarity of a star having a planet capable of hosting life at all, much less an advanced civilization that was existent at a time when electromagnetic radiation from it might be detected by us now.  If Wilson is correct about the very remote possibility that Homo sapiens could have evolved on Earth, the odds against there being a similar one extraterrestrially are even larger than I thought.  Could we therefore be alone in the Galaxy, dare I say in the universe?  We'll probably never know.  Bummer again.

  I sometimes wish that newly developing scientific theories didn't get in the way of one's fondest hopes.