Tuesday, March 6, 2012

Altruism -- can we do good just for the sake of it, after all?

Ant colony; Wikimedia Commons
Altruism, organisms being good to others even at their own risk, has perplexed true Darwinists for 150 years.  It even perplexed Darwin, who brilliantly anticipated numerous potential challenges to his theory, including the possibility that the existence of altruism, in a world he painted as red in tooth and claw, could destroy it.

The March 5 issue of The New Yorker addresses the issue in a piece (subscription required) by Jonah Lehrer, "Kin and Kind."
According to legend, the biologist J.B.S. Haldane was several pints into the evening when he was asked how far he would go to save the life of another person.  Haldane thought of a moment, and then started scribbling on the back of a napkin.  "I would would jump into a river to save eight cousins, but not seven."  His drunken answer summarized a powerful scientific idea.  Because individuals share much of their genome with close relatives, a trait will also persist if it leads to the survival of their kin.  According to Haldane's moral arithmetic, making a sacrifice for a family member is just another way of promoting our own DNA.
That settled it.  Altruism is selfish after all.  Evolutionary biologist, William Hamilton, formalized the idea in an equation published in 1975, in what came to be called inclusive fitness:

      rb > c
      is "degree of relatedness",
      is the reproductive benefit to the recipient of the altruistic behavior, and
      is the reproductive cost to the altruist.

In very basic terms, you and your sib, parent, or child share half your genes.  This is on average and it's statistical.  You can't say in advance which genetic variants you'll share, just that overall it'll be half of them.  That's because everyone gets half their genes from their father, half from their mother.   So, if you do something for your sib that puts you at risk, say, of having one of your own children, but your assistance leads your sib to have at least 2 children s/he that wouldn't have had without your help, then the genetic variants you carry will, on average, proliferate--via your sib's children who will carry those variants.

Under these conditions, if a variant in question leads you to this helpful rescuing behavior, the variant will (statistically) proliferate, because helping your sib to have more children than you give up will increase the frequency of those helping-variants in the next generation.  Likewise, you share 1/8 of your variants with your cousins, so to give up a child of your own by helping your cousin, that cousin would have to have at least 8 more children than without your help.  That's what Haldane meant.  This may make little sense in slow reproducers like humans, but could actually work, in principle at least, in fast reproducers who produce hundreds or thousands of offspring--like ants.

So, Hamilton's rule seemed to explain why vampire bats feed each other, why bees will sting, and die, to defend the hive, and why Ken dove into a pool to save a drowning stranger years ago.  It even came to explain things that had nothing to do with altruism, such as homosexuality, which could evolve because homosexuals cared for the offspring of their kin, thus perpetuating their own genes even if they themselves didn't reproduce.

This would seem to show clearly that, by itself, Hamilton's rule simply cannot explain human (or even primate) sociality.  In all human societies people routinely help their cousins and other more lineally distant relatives.  But primates simply cannot have 8 or more additional children as a result of being helped.  So those who have thought about this have had to devise various escape-value explanations to preserve the essence of Hamilton's rule; one is 'generalized reciprocity' the idea that I may help you because some day you may return the favor.  But with such escape valves, and the complexity of society, it should long ago have been clear that all bets are off.

And, the entomologist, E.O. Wilson, became enchanted with the idea, and used it to explain ant behavior, as well as human, in his book that got Sociobiology -- the idea, essentially, that behavior can be explained genetically -- up and running. His last chapter, which anthropologists knew at the time was very ill-advised if not downright naive, applied all of this to humans, in very superficial ways.  But he started a fad -- or ideology, or even a cult of sociobiology that was nowhere so fervently applied as it was to humans.

But now Wilson has changed his mind, and thinks inclusive fitness doesn't explain altruism, or much else, after all.  And this is making a big splash in the field of evolutionary biology and even in the popular press, as the Lehrer piece shows. This is part of the cult of the celebrity science, and the good fodder it makes for the popular media.  It's interesting that we were supposed to believe Wilson when he was a Hamilton devoté, and now again when he's decidedly not.  It's like Francis Fukuyama, who wrote The End of History in 1992, arguing that liberal democracies were the final stage in the development of governmental form, and then changed his mind.  He was also a leading neocon, until he wasn't.  And he's still a media darling.  Why do those who were anointed shepherd remain shepherds forever, no matter what they do to destroy their own credibility, and the rest of us are sheep forever?

In any case, the signal, and among the strongest, theoretical examples of the way that what appears to be nice can be shown to be calculatedly nasty,  that was the particular genetic relationships among the different classes of members of a hive in many ant species, simply isn't right.  It doesn't explain what it was held, fervidly and combatively, to show.

Haplodiploidy in bees; Encycl. Britannica
In the supposed canonical case of ants, this had to do with what is called 'haplodiploidy', too much to go into here unless we're requested to do that, but can easily be found in sources like Wikipedia.  The gist is that there are genetically sterile castes....and how could that happen?  What genetic variation, that led to your being sterile, could possibly proliferate in the presence of more 'selfish' variation?  The answer is that the sterile caste members are related to the Queen for whom they sacrifice their own chances at reproduction.

However, this genetic situation simply is not closely associated with sociality even among insects: some have haplodiploidy but don't live in social hives, some in social hives don't have haplodiploidy.  Many behavioral-evolutionary anthropologists seem to be  unaware of any of these unsupportive facts -- clear and repeated exceptions. It is these facts that led E.O. Wilson to abandon his prior strong advocacy of inclusive fitness and, indeed, his coined field of Sociobiology.  But Wilson, now in his dotage, is as simplistic in his new statements as he was in his strong advocacy of sociobiology.

Why is the demise of Hamilton's rule as Gospel such a big deal?  Because it shouldn't have been a Big Deal in the first place.  And yet why should we care what Wilson says this time around anyway?

The problem with all of this is the desire or even deep hunger, to find some precise, competition-centered pat explanation for observations about life. Anything that looks organized is assumed to be due to systematic, force-like Darwinian competition.  Even group selection, which Wilson is now advocating, is a simplistic notion, that orthodox Darwinians cannot accept because it doesn't work strictly at the level of the individual which they insist, for some good reasons, it must, since it is only individuals who carry genes and either do or don't reproduce.  From that point of view, everything that looks cooperative simply must have arisen and/or work strictly to the advantage of the individual.  Or, to be even more precise, it has to work at the level of individual genes.  It has to, to seem like real science!

This is a reverse kind of logic.  If you view the world as horribly selfish and cruel, then of course anything can be explained by selfishness.  On the other hand, if you see cooperation as being important, you can argue that things good for a group advance even if genetically they arise only in one member of the group.  You can argue that over time, the kindliness genes will spread and advance: each kindliness mutation will add to the group's success.  Even those without kindliness variants will do well, but they won't out-do their nicer peers.  Arch Darwinists who seem to be convinced the world is full of cheaters (does this imply that they know they're cheaters themselves, and is some sort of tacit confession?), will always devise (again post hoc) reasons why kindness for unselfish reasons will never win.  Or they will always be able to find reasons why kindness is just competition in disguise.

Cooperation, and we wrote our book Mermaid's Tale largely about it, is pervasive and ubiquitous.  Life is about molecules interacting, cell compartments interacting, cells, organs, and organisms interacting.  Cooperation means co-operation, and only in some social animal contexts is it about cozy kindly interactions including the sort of interactions referred to as 'altruism'.  If an enzyme and its substrate interact to bring about a reaction, that is cooperation.  If one component has the wrong structure or isn't present when the other is, the interaction doesn't occur.  One can't just evolve by out-competing the other.  Things may arise individually, but in various ways must advance in prevalence by successful interactions.  If this is extended to the thousands of interactions in a cell, and among cells in an organism, then why not among organisms in a population?

Sometimes inter-individual competition does certainly occur and sometimes this seems clearly to be related to genetic differences.  And even if there may be some elements of competition -- in the restricted sense simply of some things proliferating faster than others, that fact doesn't gainsay the predominance of cooperation as a fundamental part of the road to success.  Much more of the time what goes on in life is about successful interactions.  Why we resist that recognition is unclear, unless it has to do with the legacy of capitalism and colonialism, and things like that, as some historians and sociologists of science, or opponents of religion, have argued.

Well, the big debate is merely scientists' egos and tribalism speaking.  The obvious truth is that there aren't rules of this simple form for life.  Instead, life by its very nature only has to do what it does.  So if local groups are made of close relatives because individuals are born, live, and die in a general local area, then all one has to have is some sense of parental feeling to be easily extended to sociality.  This is so widespread that in a sense it doesn't require any special explanation or theory at all.  It doesn't require rigid, ubiquitous, or formalized theory--no matter how urgently mathematical biologists want it to be.  And mathematical models are by their own very nature law-like, rigid types of relationship that are far from fitting the realities of Nature--even if those models show how Nature would work to the extent the circumstances resemble the model.  Just as Hamilton's rule, taken properly as a generic guide, is informative.

The idea that if you help kin to an extent as predicted by Hamilton's principles, you'll statistically advance copies of your genes is simply a fact.  But it's also a huge 'if', and the many subtleties and nuances and other sources of variation are so great that, as with  most things in evolution, the theory can't be expected to apply rigidly or always.  Most things drift in or out of populations with little, or perhaps only occasional, help from classical natural selection.  We've discussed this in many posts on MT.  The essential cooperativity is entailed, among other things, by the nature of life as being organized around polymers (DNA and proteins) as we described in a series of recent posts, too.  Again, just because something is plausible and mathematically sound, doesn't mean it happens in real life.

In this sense, which we think is truly profound, life is not like physics and is not a science that requires the kind of rigidity or formal rigor that physical sciences do.  The reason, in a sense, is that life is by its very nature all about differences!  Differences are what enable evolution.

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