slime and minds

My intellectual career began with the reading of two books under the guide of an excellent teacher: Jeffrey Wallin.  The Crisis of the House Divided, by Harry Jaffa, convinced me that the principles of the Declaration of Independence, as articulated by Abraham Lincoln, provided a solid foundation for an understanding of justice.  All human beings are in fact created equal, endowed by the laws of nature to certain unalienable rights. 

Natural Right and History, by Leo Strauss, convinced me that the account of justice articulated by the Socratic philosophers-Socrates, Plato and Xenophon, and Aristotle, was superior to the relativism and historicism that then still dominated the historical and social sciences.  At the bottom of this choice was a fundamental metaphysical question: are human beings part of the natural order, such that human nature can be understood in the way that the nature of other living things can be understood?  Or are the human things-individual psychologies and collective cultures-somehow sequestered, walled off from our biological nature? 

There was never any good reason to believe the latter.  It has become increasingly untenable.  By contrast, the Socratic approach now has compelling support from modern biology.  Just as human beings share much of our natural endowment with other living organisms, so those organisms should present at least elemental forms of our highest spiritual capacities.  If anything unifies the Socratic approach it is the idea that the nature that surrounds, if not possessed of logos, is at least logical. 

Powerful support for that idea is found in recent research into the humble slime mold.  Slime molds are republics of amoebae.  The citizens of that republic are single eukaryotic cells.  As they grow they form clusters and then tubes that squeeze columns of their brethren alone, like tooth paste squeezed out the nozzle.  These tubes grow out in search of food. 

The current episode of NOVA is a marvelous account of how intelligent these slime mold colonies are.  They can navigate a maze.  They can explore corridors and quickly abandon fruitless routes.  They can learn where they have been before and learn that certain unpleasant routes (a salt covered bridge for example) are nonetheless the routes to plentiful food sources.  How they do all this is the next mystery, but they do it. 

I am hesitant to call this behavior intelligence, as the scientists interviewed are tempted to do.  For my part, that is a translator’s bias.  I translate the Greek nous as intelligence, and nous indicates an understanding of what something really is.  That requires a conscious mind.  Slime mold amoebae have no brains or nervous systems.  It is unlikely that they are conscious. 

I have no hesitation in saying that the slime mold colony presents a mind.  The colony acquires information about its environment and processes that information into action strategically.  If that’s not mind, I don’t know what is. 

I am, I would like to tell myself, capable of nous.  This is because my brain is a much more sophisticated thing than a slime mold colony.  In one respect, it is much the same.  My brain has about eighty-six billion neurons.  These are just single cells capable interesting electro-chemical reactions, but they are wired together in such a way as to allow me to read Plato’s Republic.  This doesn’t mean that my thinking is reduced to mere slime.  It means that the slime had the potential for philosophy.

Contra Genetic Determinism

 One of the things you are warned against if you study (or dare to teach) logic is the strawman argument.  This informal fallacy occurs when someone more or less deliberately constructs a weakened version of her opponent’s argument (the straw man) in order to easily knock it down.  You say that people have a right to bear arms.  Should we really allow anyone to walk around with a grenade launcher? 

My least favorite strawman argument is expressed in the phrase it’s not all in the genes.  When I searched for that phrase a moment ago, Google reported one hundred and fifty-three million results.  It is apparently a popular straw man. 

It is always deployed as if it were a response to someone who claims that it is “all in the genes.”  That phrase indicates the idea of genetic determinism.  It is conceivable that individual minds and behaviors are largely controlled by genes in the same way that a player piano is controlled by the holes in a rotating scroll.  I say largely because I wish to avoid building my own strawman. 

The reason that “all in the genes” indicates a straw man is that no one believes in genetic determinism.  Genes provide the fundamental elements of the recipe that an organism uses to build itself from its beginning and maintain itself during its life.  That is indeed most of the story of how I came to be and continue to be a human being.  It is not at all the entire story nor even the most dramatic part of the story.

Many of the “not in the genes” refer to epigenetics.  How genes are packaged in the nucleus of a cell can determine which genes are expressed and how they are expressed in the actualized individual.  Epigenetic changes frequently result of environmental influences.  A mouse whose mother is devotedly nurtured and fondled by her mother will not only do the same to her offspring, but those offspring will inherit the same tendency.  This is a very important discovery which should be but has yet to be integrated into social science. 

This implicates one of my chief interests as somewhat reconstructed Aristotelian: the concept of species.  This article by Peter Ward in Nautilus tells the story. 

Work along the Great Barrier Reef in the 1990s had shown that two different and accepted species are present. One, Nautilus pompilius, is the most widespread of all the nautiluses across their vast Pacific and Indian Ocean range. The second, Nautilus stenomphalus, is found only on the Great Barrier Reef. It differs from the more common N. pompilius in having a hole right at the center of its shell. (In N. pompilius, there is a thick calcareous plug.) There are also marked differences in shell coloration and pattern of stripes on the shell. But when the Australian species was first brought up from its 1,000-foot habitat alive, in the late 20th century, scientists were astonished to find that N. stenomphalus has markedly different anatomy as well on its thick “hood,” a large fleshy area that protects the interior guts and other anatomical soft parts when the animal pulls into its shell. In N. pompilius the hood is covered with low bumps of flesh, like warts. Meanwhile the N. stenomphalus hood is covered with a forest of brushy projections that rise above the hood like a thick carpet of twiggy moss, or tiny trees of flesh; the coloration of the hood is also radically different.

So we have not one nautilus but two different… what is the plural of nautilus?  The two were recognized as distinct species, but what does that mean? 

A species can be defined as an interbreeding or potentially interbreeding population of organisms (the most useful but not only useful account, in my opinion) or as branches of the phylogenetic tree.  Either way, you would expect the two to have distinct sets of genetic inheritance.  No. 

We caught 30 nautiluses over nine days, snipped off a one-millimeter-long tip of one of each nautilus’ 90 tentacles, and returned all back to their habitats alive (if cranky). All the samples were later analyzed in the large machines that read DNA sequences, and to our complete surprise we found that the DNA of N. pompilius and the morphologically different N. stenomphalus was identical. No genetic difference, yet radically different morphology.

Let’s repeat that: no genetic difference, yet radically different morphology.  Genes do not even determine the final physical structure of an organism such as this, though to be sure they heavily influence it and explain the common morphological traits.  So much for it’s all in the genes. 

I would add that the difference between the two species is not determined by the environment either.  It is determined by the interaction between the common biologically heritable factors and the environment.  The ontogeny, or development of these creatures is a dialogue, not a recitation. 

What is true of biological structures is much truer of minds and behaviors.  A human being becomes what she is by a series of dialogues between her genome and the environment and between herself and the human community with which she interacts.  In this series of dialogues, she is not the least of the dramatis personae.