A battle has been raging in biology for a few decades,
about the role of cooperation in evolution. Is evolution primarily driven by
competition or cooperation? Darwin posited his theory of evolution on the basis
that competition for life dominates in the natural world. He saw that far more
offspring of any given species are born than can survive in any given situation
and location, so there's an intense struggle for survival—which later came to
be dubbed “survival of the fittest.” (That’s not Darwin’s term, but was coined
by enthusiasts who followed him.) Those critters most fit will survive and
those less so will perish...it's that simple and that brutal.
Any tiny
advantage—any favorable minuscule genetic mutation that pops up—may offer a
critter a wee bit better chance of survival that its competitors. If the
critter does have a better chance of staying alive, it has a better chance of reproducing
and sending that advantage into the future. In contrast, a tiny disadvantage
in a genetic mutation may see the critter die early and fail to send its
genes into the future. It's the end of the line for that less favorable
mutation.
So far, what I have described is no cause for the disagreement
that prevails between the opposing biological camps. They both agree…thus far.
The debate enters when we come to consider what's called “inclusiveness
fitness”—when a critter sacrifices itself for others. Martyrdom prevents one's
genes from continuing on, and since the propagation of one's genes into the
future seems to be a driving factor, how can one explain the systematic
willingness of some members of a species to sacrifice themselves for others,
when that sacrifice terminates one's genes? If all critters are driven solely by
the urge to send their genes into the future, how does one account for those
who voluntarily give up that drive?
Richard Dawkins is a prominent leader of the camp that
considers our genes to be firmly in control—that we are “driven” by our “selfish
genes.” He writes that our behavior is literally determined by our self-seeking
genes, simply to transport them into the future. Dawkins’s camp insists that
inclusive fitness is the only way to explain
why some members of a species will sacrifice themselves. All members of a bee
colony, for example, share common genes (they are all sisters). Thus, if a sister
sacrifices itself, it's doing so to protect the family—the family's genes
will survive, even if the individual bee dies. Similarly, a human being may
sacrifice himself for a close family member. By doing so, his genes will get
terminated, but the family genes may go on.
That's all fine. There’s still no real argument among
biologists. The debate comes in because there are a few situations where
individuals will sacrifice themselves for others who are not family
members. What's going on here? How do you explain why someone would willingly
give up her chance to send her own genes into the future, just to help foreign
genes to survive? Does this not seem to violate the principle that we are
controlled by our selfish genes? This is the core of the disagreement between
the biology camps.
More on our capacity to cooperate next time…
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