View Full Version : A Newer Synthesis?

James Brody
May 12th, 2006, 07:46 PM
Several parallel lines of inquiry race. My score card follows, inspired by an email from some Russian "theoreticians" that had questions about "preadaptations" and our fundamental reliance on natural selection but without clear links to variation or to orthogenetic concerns.

Variation, however, has many origins and I delivered my favorite tour...



Dear Oleg & Michael:

Dr. Levin forwarded your note; I will do my best to respond, addressing your questions but possibly giving my own favorite answers to anything that I am asked!

First, I appreciate your questions: they have been my own but I've had opportunity to combine concepts from several exciting, parallel strands in evolutionary-developmental biology and elementary physics. I find structure where there was chaos.

1) Jacob (2000) stated the basic model for all of us: nature works in modules whether quarks, macromolecules, clumps of DNA, or human instinct. Like any child with a set of Legos, we achieve vast combinatorial power when we rearrange our blocks. Nature realized this trick first. (Richard Lewontin, 2000, is a valuable supplement to Jacob. You are handicapped if you proceed with only one of them.)

2) Kirschner and Gerhart (1998, 2005) provide leads as to how small smelly squishy things became edifices. Their concept of "exploratory system" is particularly valuable as it applies to angiogenesis, immune systems, neural crest cells, calluses, neural organizations, and even our vocabularies (Brody 2004, 2005). There are good examples of linkages between modules that disconnect and reconnect in new ways in relation to stress. Darwin's problem about the sources of variation is a smaller one.

3) Rudolf Raff (1996) and his network recombined (an old trick in nature) developmental biology and evolutionary biology. Briefly, the evolution of adult forms (phylogeny) depends on the evolution of ontogeny. The "magic" strategy appears to be duplicate, compartmentalize, vary the duplicate, and may selection do its best or worst. Compartmentation allows "parallel, loosely interconnected, cascades of development." Heads and guts can pursue semi-independent evolutionary paths. In the extreme, the 7-14 hox genes that underly human "segmentation" might allow a girl at the mall to have a beautiful face, fine breasts, and a flat stomach, but chubby legs with thick ankles: each of her compartments is its own experiment across millennia.

4) Albert Barabasi (2002) gave us a fine introduction to emergent networks. Emergent networks are described best by power lows and not by Gaussian distributions. They are usually jam-free, allow immense numbers of members, and close connectivity between all of them.

My own speculation is that emergent networks vary in organizational detail according to resource availability: local neighborhoods become larger and less varied as recources decline. (Bose-Einstein gasses have the same property. See Reka & Barabasi, 2002.) That is, reduce resources and "winner-take-all" structures appear in which all the small units report to one central one. Wal-Mart, popular music, success as a cocaine dealer, or a writer follow the patterns of emergent networks: so does socialism, so did fascism. So did the organization of cellular chemistry. So does the emergence (phylo- or ontogenetic) of thought. (The economist, Steven Levitt, 2005, goes through contemporary examples of winner-take-all. Frank & Cook, 1995, did a similar job in a boring way!)

You might also consider emergent networks to have a meaningful concept of "fitness" that escapes some of the older problems with that term and a meaningful explanation of religion: humans flock for the same reasons as clumps of bacteria or herds of elk. And "flocks" are simply another exploratory system.

5) In regard to hereditary behaviors: this is now familiar stuff. Barkow, Cosmides, and Tooby (1992) reopened the post-Victorian case for human instinct but in a perverse way, argued that genetics requires that we all have the same set of instincts and that a universal human nature exists. Buss (2003) summarizes most of the adaptationist literature.

I'm personally more convinced about the clinical importance of individual variation and that, perhaps, as much as 80% of it may be attributed to chemistry, whether through our customary concepts of heritability or through its combination with "nonshared environments": the environments specific to an individual and strongly constructed by that individual according to his "genetic propensities." Cohen (1999) and Rowe (1994) state the case well and without the Greek that often escorts behavior genetics.

Thus, I am a mosaic of my father and mother with his nose, eyes, and forehead, her mouth and chin; his quiet persistence and writing characteristics, her ambition and activity level. These patterns were noticed, however, by Galton in the 1860s and quickly accepted but just as quickly rejected after the great wars when socialism tried to make us all similar to each other. (See Ridley, 2000.) Clinical needs, however, for such things as treating depression, blood pressure, and varied physiological distresses, dictate our considering them again but to protect variation rather than to reduce it. In accord with Steve Pinker's notion that "language is a spin-doctor," we first heal ourselves and later change our stories...

My best wishes...

James Brody, Ph.D.

Albert, Reka & Barabasi, A-L (2002) Statistical mechanics of complex networks. Reviews of Modern Physics 74: 47-97.
Barkow, J., Cosmides, L., & Tooby, J. (Eds.) (1992) The Adapted mind: Evolutionary Psychology and the Generation of Culture. New York: Oxford.
Brody, J. (2004) Bipolar disorder: self-interested networks, cycling, and their management. Chapter 2 in M. Brown (Ed.) Progress in Bipolar Disorder Research. Hauppage, NY: Nova Science Biomedical Series, pp. 33-64.
Brody, J. (2005) ADHD: Inhibition, Emergent Networks, and Maternal Investment. Chapter 2 in Michelle Larimer (Ed.) Attention Deficit Hyperactivity Disorder (ADHD) Research. Hauppage, NY: Nova Science Biomedical Series. pp.19-58.
Buss, D. (1999, 2003) Evolutionary Psychology: The New Science of the Mind. NY: Doubleday.
[See also: Buss, D. (2000) Dangerous Passion: Why Jealousy Is as Necessary as Love and Sex. NY: Simon & Schuster.
Buss, D. (2005) The Murderer Next Door: Why the Mind Is Designed to Kill. NY: Penguin.
Buss, D. (1994; 2003) The Evolution of Desire: Strategies of Human Mating. New York: Basic Books.]
Cohen, D. (1999) Stranger in the Nest: Do Parents Really Shape Their Child's Personality, Intelligence, or Character? NY: Wiley.
Frank, R. & Cook, P. (1995) The Winner-Take-All Society: Why the Few at the Top Get So Much More Than the Rest of Us. NY: Free Press.
Jacob, F. (1998) Of Flies, Mice, and Men. Cambridge, MA: Harvard University Press. (You can find my review at www.human-nature.com. It has appeared in 3 languages: Google will lead you to it: "James Brody, evolutionary")
Kirschner, M. & Gerhart, J. (1998) Perspective: Evolvability. Proceedings National Academy of Science. 95(15), 8420-8427.
Kirschner, M. & Gerhart, J. (2005) The Plausibility of Life: Resolving Darwin's Dilemma. New Haven, CT: Yale University Press.
Levitt, S. (2005) Freakonomics: A Rogue Economist Explores the Hidden Side of Everything. NY: Morrow.
Lewontin, R. (1998/2000) Triple Helix: Gene, Organism, Environment. Cambridge, MA, Harvard.
Pinker, S. (2002) The Blank Slate: The Modern Denial of Human Nature. NY: Viking.
Raff, Rudolf (1996) The Shape of Life. Chicago, IL: University of Chicago Press.
Ridley, M. (2000) Genome: The Autobiography of a Species in 23 Chapters. NY: Harper Collins.
Rowe, D. (1994) The Limits of Family Influence: Genes, Experience, and Behavior. NY: Guilford.

Copyright, 2006, James Brody, all rights reserved