I am very much on board with this rant. Not every trait is adaptive. So, before you can come up with a convincing adaptive explanation for a given trait, you’re going to have to convince me that it is adaptive in the first place.
This sort of “this-gene” and “that-gene” thinking may have been all fine and well in the halcyon days of yore, before the human genome was actually mapped and we could speculate all day about just how many genes we actually had (and could thus afford the luxury of “one trait , one gene” thinking), but nowadays, it’s just silly. The human genome consists of some 20,000-25,000 genes. That’s just not enough to account for every possible morphological, physiological, psychological, and behavioral trait or subtrait. We are more than the sum of our genes, therefore it is a mistake to try to trace everything back to them. We cannot predict an individual’s genome, nor can we predict the individual from the genome at this point.
It would be nice if people could ask “Is x adaptive?” before proceeding directly to “Why is x adaptive?”.
Some days it seems like almost every GQ thread title that begins with the word “why” should be asking the question that results from leaving that word off.
Guh, it’s because Evolution intended us to have mammoth burgers when the cows go extinct.
Really, the more I think about it, these “what’s the evolutionary advantage to women shrieking like little girls when they get excited?” “it’s because women who screamed got saved and the ones who were silent died off when mammoths, T-rexes, and sabre toothed tigers picked them off” questions are like just so stories but with a thin veneer of Science!™.
This is true, however it doesn’t dispell genetic predisposition - just the “one gene, one trait” version. But couldn’t it be “one specific combination of X genes, and the complex interraction of what each of them does - one trait” ?
There’s really no such thing as a gene for a “trait”. What there really is are genes that produce proteins. Different versions of genes produce different proteins, and different proteins cause different phenotypes. Some phenotypes become more common and others become less common, and to the extent those phenotype differences were caused by different genes that coded for different proteins, some genes are going to be more common in the next generation and some will be less.
That doesn’t mean that a gene that results in a protein that results in curly hair is “for” curly hair or that another allele that results in straight hair is “for” straight hair.
Bah…we find the shoe gene and the power tool gene and we have it 90 percent covered. The liberal or conservative gene covers the next 9 percent. I am sure we can cover the other one percent with the 19,998 genes left
Well, true enough. Hypothesizing without testing isn’t science.*
I should maybe have left that tangent off. My post was saying that yeah, we pretty much are cavemen. I allow that there might be some minor differences (like testosterone level), but if I’m wrong about that, then ‘we are cavemen’ is absolutely true.
*Look, humans and chimpanzees have a common ancestor. Chimpanzee males who aren’t related can’t abide each other. Archaeology shows that humans, from 50,000 years ago when they left Africa, to about 5,000 years ago (maybe a little further back) lived in small groups. Did technological advancement lead to larger communities, or did a genetic change lead to larger communities, or both, or something else? Admittedly I don’t know. But we are cavemen.
Part of the problem is that some people misundstand genetic cause and effect. To take the “Lower testosterone = Complex society” example (I’m not saying it’s true, just a handy example), the thinking is “Males evolved with lower testosterone so males could work with other males and create a complex society.” But evolution doesn’t work like that; there’s no predetermined path. The equation is not X genetic change occurred in order to Y. IF the example happened to be true, it would be more like, “Complex society was one of the consequences of lower testosterone” or “Males with higher testosterone killed each other off before they could reproduce, leaving only males with lower testosterone to reproduce.”
I know I’m not explaning it very clearly, but see the difference? (I don’t have spell check at work, so I know I’ve misspelled testosterone about a dozen times)
I’m guessing it’s also partly the swinging of the pedulum between the theories of heredity and environment. It seems that one or the other of those is significantly more favored by the chatterati at any given time.
I do have a theory that in today’s society dying relatively young gives a reproductive advantage to your offspring. I know that in my case at least, were my children to inherit now, the financial pressures they are currently facing would certainly ease, and they would probably have children earlier, and possibly more of them.
Ideally for your children you should raise them to maturity and then die, leaving them a financial windfall. Live too long, and you spend down your assets and leave them stuck. Die too soon, and you don’t have time to acquire sufficient funds. It’s a narrow window.
The problem is that it’s more complicated than even “genetic predisposition”. A good chunk of phenotype is the result of developmental timing events, not dictated directly by the genome. Plus, complicated behaviors are more the result of complicated brain “wiring” (read: neural connections & assorted chemical balances) than having a certain gene or gene complex. That makes the whole “evolutionary advantage” thing even harder to pin down, since we can’t even determine with any precision how much of that wiring – much less the consequences thereof – is actually heritable.
There is a Klingon and a Kzin outside my door fighting over who gets to talk to you.
I know you’ve backed off of this a bit, but it typifies exactly what the OP correctly picks out. AFAIK, there is no evidence that men with higher testosterone levels fight more often, nor that men who fight more often have a more difficult time residing in/forming complex societies, nor that modern man has lower testosterone levels than earlier versions, nor anything about this argument. As just one example, it may surprise you to learn that environmental stress rewires the brain in ways that make living in a society difficult, and evidently has a much greater impact than any differences in testosterone.
You assume before the fact that lower testosterone implies less fighting, which implies ability to live in more complex societies, which implies more reproductive success for the lower testosterone male. Therefore, that is what must have happened. It doesn’t work that way. If I have more kids than you, my genes win.
