After watching a BBC documentary about wild silver foxes that were bred for "tameness" and subsequently started exhibiting the entire suite of changes associated with domesticated dogs (raised tails, various hair types/colors, submissiveness, etc.) I began thinking about whether or not this process happened in humans.
Evolutionary biology, anthropology, etc. all seem to agree that the great "advances" of human society were the result of greater cooperation. Language, pair bonds, religion, the written word, all allowed us to "work together", but what if this simply means that we have "tamed" ourselves?
As in the case of the silver fox, many uniquely "human" traits may be the result of selecting for tameness.
For example, when comparing infant apes to infant humans, they both show striking similarity. What we then see in the adult ape (a Capuchin monkey in the picture) is a maturation into an adult form that is truncated in human beings.
If this is indeed the case (and it seems very likely) many other developments such as the use of other animals skins/pelts, weapons, etc. could be compensatory for our own loss of innate weaponry (i.e. canine teeth).
Paleontologist and writer Stephen Jay Gould has said that the "evolutionary story" of humans is based on "retaining to adulthood the originally juvenile features of our ancestors."
What are your thoughts?
(If you are interested, I delved a little deeper into this idea in a blog post titled "The Domestication of Man")
I definitely see this happening. When I look at skulls from Europeans even as recent as the 1600s they are much more robust and threatening. A lot of British men back then had these impressive, but kind of scary, thick brow ridges like an Neanderthal.
It seems to be acting differently in different groups of humans. Some humans are evolving towards long childhoods and late childbearing, whereas there is strong evidence that other poorer groups of people are menstruating and bearing children at younger and younger ages.
Generally speaking we are basically tamed & domesticated versions of our ancient selves, we are Zoo Humans. The majority of us live in a cage, follow the same routine usually dictated or influenced by our zoo keepers (managers, banks, morning traffic, etc), we consume 'food' that has been prepared for us, every aspect of our lives is dictated to us one way or another. The strongest chains that bind us are the invisible ones. We are given an illusion of 'choice' by our captors.
If we were suddenly transported to the wild and forced to survive or die, most of us would die. Epigenetics is becoming a major factor in our evolution.
Retaining juvenile traits into adulthood is called Neoteny, and we've got alot of that going on, it seems to be mostly about sexual selection. We like girls with a 'cute' little nose, and eyes that are big compaired with the eye to head ratio of adults, and a whole list of other features that are present in infants. Thats why everyone thinks puppys are cute, big eyes, little snouts, that look where they tilt their little heads over sideways, mammals are programed to resopond to those visual cues in a protective manner. The "I'll take care of you little guy, poor thing cant even keep its head on striaght" response. But humans, mostly girls, will do that same head to the side, big eyes look when flirting or begging dad for the car keys, and it works on dad better than on mom because he is programmed to respond to cues like that and mom knows what game is being played and is harder to fool. Since humans have the longest juvenile stage of any animal in the world, it makes sense that we may have a double dose of neotenic features in adults. And I dont mean to pick on the girls, but those are the first examples that jump to mind when i think of juvenile features held to adulthood. But as for selecting for tameness, I'm not so sure thats really what we do. Some of the first, and from a repoductive standpoint, most successful 'working together' attmepts were made be men killing and raping people. I'm thinking Genhis Khan on this one, 1 in 20 men in Asia are his desendants. He was a first class jackass but natural selection rewarded his efforts with more kids than anyone else has probably ever had. We see the same 'working together' in gangs of male chimps when they hunt and kill and eat their chimp neighbors. Its not a very nice thing to do, but they get a good meal of protein and fat and those things in large doses over time are probably what enabled us to grow such giant brains. It doesn't always pay to be a nice 'tame' guy. And usually the age at which women give birth is direclty related to the avilability of birth control, folk in really poor countries get on the nest earlier because the have little or no access to birthcontrol. More education and birthcontrol have always led to fewer children per year and the first child being born a bit later in the womans life. As far as I know.
I once spent a lot of time thinking about this question, the domestication part (the neotany thing is just another form of mutation in evolution's toolkit, so it doesnt interest me). I even thought thought up a nice name for it. I called human beings "self-cultivating cultivars".
But then, one day, watching a nature show on PBS, I saw how strongly the evolved behaviors of horses was guided by the social interactions between the mares (the stallions are less social and not as sophisticated). I forget the details now, but it became glaringly obvious that horses are also self-cultivating cultivars, despite brains the size of walnuts. Not just behaviorally, but also physically, via behaviors. So, this doesn't fascinate me anymore either.
What IS uniquely human is simply our upright posture, which allows us to maintain hunting stamina in the midday sun, a time during which horizontal four-legged animals are so exposed to solar radiation, they have to take a siesta. When you realize what that means, our earliest upright ancestors having the world to themselves every day at midday, you can derive all the rest of our evolution from that. Neotany or no. Self-cultivation or no. Those are just small matters.
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