Tuesday, March 26, 2013

Darwinian civilization


"Nature is red in tooth and claw", Charles Darwin is often quoted as writing (even though this turn of phrase actually stems from a poem by Alfred Tennyson, mourning the loss of his friend Arthur Hallam, a poem that appeared before the publication of Darwin's "Origin of Species"). Be that as it may, the phrase is designed to make us appreciate nature's cruelty, that thousands have to die for the rare variant to ascend to greater fitness, that progress must be purchased at the expense of unfathomable suffering. Evolution, we learn to understand,  is a bleak process, devoid of compassion, in a winner-take-all world. 

What does this say about us, the product of this process? Our genes were shaped for eons by teeth and claws; our purpose in life is to reproduce faster than the other guy (and prevent him from doing the same), is it not? Should we not capitulate to these tendencies bred into us via the eternal survival of the fittest, and realize that the meek and the poor are very unlikely to inherit the earth?

My view is that this is an altogether unevolved view of humanity. What is it about us humans that is remarkable, that is worth a pause? Is it our ability to think, plan, use tools, to create art? I'm afraid that if you think that this is purely our domain, you should think again: animals can do this too, they can even paint portraits.  

This is not what makes us special. What makes us special is precisely our ability to resist the Darwinian drive. People have risen above animals the moment they created civilizations. You may feel like discussing what I mean by civilization, but my meaning is really quite pedestrian: a civilization is any organization or group of humans that engages in a division of labor, and protects its members from outside groups. From this point of view, a civilization is more than an extension of the "empathic circle" beyond the close-knit kin group. Civilization also encompasses cooperation (division of labour is a form of cooperation) and in particular protection. One of the distinguishing features of a civilization is, in my view, its anti-Darwinian tendencies: to protect from elimination those that can't protect themselves. I believe that if there is any nobility in humankind it is that: empathy for fellow humans we are only distantly related to; to care for people without asking for a return, simply because it is the human thing to do. 

I also understand that not everybody shares my views concerning the value of civilization. I realize that there are fellow humans that think we ought to return to a more Darwinian society where the strong rule the weak, and where the meek (by virtue of having "chosen" to be meek) should reap the genetic consequences of defeat. In this view of life, there is no place for losers.

But, may I offer a counterargument to this, shall I call it: "The Tea Party reads Darwin for the First Time" view?  

What follows may become a bit technical, so I'm afraid I may lose some of my Tea Party readers. But I do encourage you all to hang on.

"Nature, red in tooth and claw" emphasizes the strength and brutality of selection, but by itself selection cannot create progress. Progress, defined here as "increasing the fit" of an organism to its environment, requires variation. You immediately see that this is true: if all organism are identical (genetically and phenotypically, that is, in their appearance), then no amount of selection will help you if the environment changes, for example. We would all be doomed (identically so) if the new world is inhospitable to us. Because we would all be screwed in the same manner. Progress, in the light of a changing environment, can only come about if there is diversity. What if you and I are different enough so that I cannot cope with the changed environment, but you—as it turns out—can? Then you will found the lineage that will inherit the Earth. Because you were different. And I was not.

That this diversity—or variation as it is more properly called within the field of population genetics (the mathematical formulation of Darwinism)—is important for adaptation is an old hat (so to speak), commonly going by the moniker "Fisher's Fundamental Theorem" of evolution. What is less well-known is how populations go about maintaining the necessary variation in populations to assure that they can adapt when times are a-changin'. Because here it is: if what makes us who we are is determined largely by our genes, then maintaining diversity requires maintaining a diversity of genes. But what if an individual possesses a gene that is just one change away from fantastic, but in the absence of that change is rather dull, or worse, inferior? This individual, one change away from greatness (and founding the other lineage that will inherit the Earth) is vulnerable. It is meek. It is unprotected. The tooth and the claw will likely eliminate it so that its (potential) greatness will never be revealed. Darwinian dynamics is cruel for sure, but also sometimes shortsighted. Couldn't we do better? Is it possible that by protecting the weak we actually foster the type of "valley-crossing" events that Darwinian evolution has a hard time to effect, but relies on for the occasional fundamental change?  

Perhaps the answer is "Yes, we can". But, what is the cost of keeping around the meek? There is a cost, for sure. The meek are plentiful, because there are more ways to diminish genes than there are to improve them. The potential, however, is boundless. Within the field of evolutionary biology, we practitioners spend countless hours to understand the mechanisms that molecular biology uses to increase and maintain variation: recombination, negative frequency-dependent selection, increased mutation rate, linkage, and much more. But we compassionate humans can transcend molecular mechanisms: we can maintain diversity simply because we believe in giving people a chance, that every person on Earth has the right to attempt to realize their dreams and passions, to "live a healthy and productive life". And just perhaps, keeping around the "tired, the poor, the huddled masses yearning to breathe free" may be the thing to ensure the survival of the truly evolved species, one that understands that the "wretched refuse of your teeming shores" may very well constitute the genetic key to survival in tomorrow's changed world. 

So, could it be that a compassionate and altruistic civilization could actually transcend Darwinian dynamics by outwitting the demon of selection, so as to allow an unheard-of level of valley crossings? It would be fitting, wouldn't it, given that the segment of the (U.S.) population that most argues for promoting the survival of only the fittest in human civilization, is precisely the one that has the most problems with the science of evolution. 

Disclaimer: This blog post may or may not have been influenced by the Adami Lab's emphasis on understanding the features of fitness landscapes that make valley crossings a fundamental feature of Darwinian adaptation. 



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