The Genetics of Altruism
I've just had the week from hell. It started with getting slammed by some
flu mutation that found me deliriously walking into walls. Fever, aches, etc.
I slept on the floor in the other room to make sure my wife got some good
sleep (and didn't want to expose her too much). I woke up with a stiff and
I didn't feel like doing my morning yoga routine, but wish I had when a
coughing fit threw out my back. I then spent the next couple of days in bed, and
moping around the house like Frankenstein's monster.
It is weeks like this that really demonstrate evolution.
Why? Well, first of all, I've had the flu before… couple of times, for sure.
Why do I keep getting it? It evolves and mutates its chemical signature so that
my antibodies don't register it as the same thing I got last year.
Second, sprained backs. Think about it. The first adaptation from our common-chimpanzee-ancestor
was our knees. We stood upright before our heads swelled to hold our bulbous
brains. The back adapted, but not very well. It connects to the pelvis at the
wrong angle, and so our muscles compensate. This is why we have this curve at
the bottom of our backs.
This works well enough until our thirties, for when we are young, our muscles
are typically strong enough to hold everything together, but then they wear
out and give out. But by then, the evolutionary damage has been done… we've
already passed these faulty back genes on to the next generation.
So if I had lived to forty, I probably wouldn't have lasted much longer, for
it is difficult to outrun a smilodon with a sprained back.
So, while flat on my back reading Stephen Jay Gould's Bully For Brontosaurus,
I've tried to find solace in my misery… and tried not to think of the
smilodons in my closet.
I've also been thinking about the altruism gene. For you know, if natural
selection is true, then we must have some gene in us that makes behave nicely
to each other. Of course, this gene must be recessive next to
the mean and cruel gene.
Of course, while biologists are looking for this gene, Gould explains it very
well in the last chapter of his first book, Ever Since Darwin. Let me briefly
explain the concept that essentially started when J.B.S. Haldane famously
said in a pub one time that, "I'd lay down my life for two brothers or eight cousins".
What he meant was that since we get half of our genes from our mother and the
other half from our father, each of our siblings would statistically share
half of our genes. So, if you are walking through the woods with your three
brothers and a bear steps out, you can sacrifice yourself to save your three
brothers, since all of your genes will flee with them. (see this article
for more on the concept of Kin Selection).
Once we start changing our thinking from "survival of the fittest" to the more
accurate idea of "propagation of genes" (that's right, it's all about the sex),
we clearly understand how and why one can
pass on one's genes without direct reproduction. Think of a wolf pack. Only
the dominate pair actually mate and have puppies. The other adult wolves
help to raise them, since being in a family, the puppies are probably cousins,
and so a collection of eight puppies will contain each of the adult's genes.
I've heard people talk about how homosexuality doesn't make evolutionary sense,
since someone who prefers the same gender wouldn't have offspring, and therefore,
wouldn't pass on their genes, and therefore those genes would die off relatively
But humans, like wolves, are pack animals, and our survival for thousands and
thousands of years have been based on small, closely-related tribes… packs.
And having homosexuals around to help raise children because they contain their genes
may have helped to maintain early human social structures. That's right, it
may have been homosexuals that strengthened the family.
My point to all of this rambling? Nothing really, other than I'm just really
fascinated by how well evolution predicts and explains the world.
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