Evolution of childhood: Prolonged development helped Homo sapiens succeed

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There’s a misconception among a lot of us Homo sapiens that we and our direct ancestors are the only humans ever to have walked the planet. It turns out that the emergence of our kind isn’t nearly that simple. The whole story of human evolution is messy, and the more we look into the matter, the messier it becomes.

Paleoanthropologists have discovered as many as 27 different human species (the experts tend to debate where to draw the line between groups). These hominids diverged after our lineage split from a common ancestor we shared with chimpanzees 7 million years ago, give or take a few hundred millennia.

Many of these species crossed paths, competed, and mated. Populations ebbed and flowed in tight little tribes, at first on the expanding savannahs of Africa, later throughout Europe, Asia, and all the way to Indonesia. Just 100,000 years ago, there were several human species sharing the planet, possibly more: Neanderthals in Europe and West Asia, the mysterious Denisovan people of Siberia, the recently discovered Red Deer Cave people living in southern China, Homo floresiensis (the Hobbits of Indonesia), and other yet unknown descendants of Homo erectus who left indications that they were around (the DNA of specialized body lice, to be specific). And, of course, there was our kind, Homo sapiens sapiens (the wise, wise ones), still living in Africa, not yet having departed the mother continent. At most, each species consisted of a few tens of thousands of people hanging on by their battered fingernails. Somehow, out of all of these struggles, our particular brand of human emerged as the sole survivor and then went on, rather rapidly, to materially rearrange the world.

If there once were so many other human species wandering the planet, why are we alone still standing? After all, couldn’t another version or two have survived and coexisted with us on a world as large as ours? Lions and tigers coexist; so do jaguars and cheetahs. Gorillas, orangutans, bonobos, and chimpanzees do as well (though barely). Two kinds of elephants and multiple versions of dolphins, sharks, bears, birds, and beetles—countless beetles—inhabit the planet. Yet only one kind of human? Why?

Written By: Chip Walter
continue to source article at slate.com

9 COMMENTS

  1. If there once were so many other human species wandering the planet, why are we alone still standing?

    Probably because we killed or pushed the others out of their habitats – like we are doing with chimps, orangs and gorillas.

    Chimps like some humans also hunt, kill, and eat other monkeys – such as Colobus.

  2. I think we killed off the other human species at least the smaller populations, the way the American grey squirrel is killing off the red squirrel, we may have mated with others and we are possibly a hybrid of two or more species the way dogs are of mixed breeds today.

  3. In reply to #6 by Dublin-atheist:

    I think we killed off the other human species at least the smaller populations, the way the American grey squirrel is killing off the red squirrel, we may have mated with others and we are possibly a hybrid of two or more species the way dogs are of mixed breeds today.

    I agree with the jist of your post as a real possibility, however dogs are all the same species, I believe. I don’t necessarily think that we set out to exterminate other species though, as you calmly and Alan4discussion boldly suggest. That opinion comes across as merely bleeding-heart, hippie Liberal drivel, along the lines of saying “I think we cut down the Neanderthals rain forests and paved Walmart parking lots over their homes.” Unless there is supporting evidence to support such a claim, it’s just an unfounded guess with a heavy Leftward lean to it.

  4. Neotenous unwired brains give us the possibility of rich moderately stable cultures (but not so stable that we can’t change direction in a few generations.)

    For childhood to work at all we have to have good enough copying of cultural attributes by children from their parents and elders so that learned solutions to problems in rapidly changing environments, say, can be reliably enough passed on. Nor can cultural evolution work if the copying isn’t nearly perfect. If the attribute has been nearly mangled by the second generation copy there can be no progress.

    This is mid Feb’s posting early.

    Here is how copying became good enough in human children, thanks to a shed load more mirror neurons and a trust in authority before the evidence of their own eyes.

  5. Prolonged childhood is necessary to prepare the child for the successful survival in the modern day society that puts tremendous pressures on humans despite biological principles. Hypothetically, if a child is trained how to obtain food on their own from a very early age and let go, it will be doing so just like all other non-human animals.

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