In The Flying Tiger. Women Shamans and Storytellers of the Amur, Kira van Deusen mentions that the Tungus peoples of far eastern Siberia often refer to the past existence of "monkey" people in their region. One folk-tale describes how these "monkeys" once abducted a man:
So the older sister took the shaman's drum. She started to sing and then said, "Brother, when you go hunting in the taiga tomorrow, you're going to meet two people. Check out their breasts, and then marry them."
The next day, he woke up and set out to go hunting. He walked and walked and came to a hill, a mountain. There were big rocks. He looked up, and then went on. Suddenly he saw two people sitting there. He approached and at that time the ties on his skis broke.
He came up to those people and felt their breasts and they were women. And they took him along with them.
At home time went by. A day passed and another, and still he was gone. Many days went by. And then the younger sister said, "Sister, you made this happen. Now you bring him back. Those two monkeys in the mountain came and took him away and now they are keeping him in the mountains, sucking his blood. He's become just skin and bones."
… So the younger sister sang and drummed, flying to her spirits, but she couldn't get there. She tried a second time and still didn't have the strength. The third time she gathered all her strength and flew to those rocks. She took her brother and dragged him out of there. He flew, looking thin as a shirt. They got him back and healed him. And that's how the younger sister brought her brother back from those monkeys.
… So that's it about the monkeys. They lived in the rocks and when they rolled back and forth, they called, "Tsyoo, tsyoo, papandasyoo!!" (Deusen 2001:126-128)
Macaques inhabit East Asia and may once have existed as far north as the Amur, but none come close to human size, the males having a head and body length of about 41-70 cm. There is, however, another candidate: the last large non-human primate to inhabit the region—Neanderthal Man.
The Neanderthals inhabited Asia as far east as the Tien Shan mountains and Lake Baikal. Southern Siberia has several Mousterian sites, with some yielding Neanderthal bone fragments. The youngest site is dated to 28,000 BP (Goebel 1999). Recent mtDNA analysis has confirmed the Neanderthal identity of 30,000- to 38,000-year-old human fossils from Uzbekistan and the Atlai region of southern Siberia (Pennisi 2007).
When modern humans began to spread out of Africa, they quickly replaced Neanderthals throughout West Asia as far as the Aegean and Black Sea littoral. This wave of advance is attested by cranial remains of modern humans from Crete dated to 51,000 BP (Facchini and Giusberti 1992) and by early Aurignacian assemblages from Israel, Lebanon, and Bulgaria dated to 45,000-42,000 BP (Mellars 1992; Phillips 1987; Schwarcz et al. 1979; more). A secondary wave of advance seems to have spread out of eastern Africa through southern Arabia and into India c. 50,000 BP (Quintana-Murci et al. 1999).
The rapidity of this two-pronged advance should be no surprise, given the ecological similarities between the Middle East and northeastern Africa. The real "Out of Africa" event occurred further north, where modern humans entered environments with wide seasonal variations and different means of subsistence. On encountering boreal and alpine environments, the wave of advance would have slowed and shifted into a "hurry up and wait" mode, i.e., gradual adaptation in areas of ecological transition, followed by rapid penetration and colonization once sufficient adaptation had been achieved.
Modern humans penetrated the extensive alpine environments of central Asia fairly late, probably after the last ice age. It is also from this vast region that we have reports of large human-like creatures, notably the Yeti (commonly known as the Abominable Snowman). Like the "monkeys" of the Amur, the Yeti was believed to live in high rocky places (Yeti means "rocky place bear" in Tibetan).
Was Yeti an eastern Neanderthal? We may soon have an answer, thanks to the soon-to-be completed map of the Neanderthal genome and hair/skin samples that allegedly come from a Yeti.
References
Deusen, K.V. 2001. The Flying Tiger. Women Shamans and Storytellers of the Amur. Montreal: McGill-Queen's University Press.
Facchini, F., and Giusberti, G. 1992. Homo sapiens sapiens remains from the island of Crete. In Continuity or Replacement. Controversies in Homo Sapiens Evolution. G. Bräuer, and F.H. Smith (Eds.). Rotterdam: A.A. Balkema, pp. 189-208.
Goebel, T. 1999. Pleistocene human colonization of Siberia and peopling of the Americas: An ecological approach. Evolutionary Anthropology 8:208-227.
Mellars, P.A. 1992. Archaeology and the population-dispersal hypothesis of modern human origins in Europe. Philosophical Transactions of the Royal Society of London. Series B 337:225-234.
Pennisi E. 2007. No sex please, we're Neandertals. Science 316:967. doi:10.1126/science.316.5827.967a
Phillips, J.L. 1987. Upper Paleolithic hunter-gatherers in the Wadi Feiran, southern Sinai. In The Pleistocene Old World. O. Soffer (Ed.). New York: Plenum Press, pp. 169-182.
Quintana-Murci, L., Semino, O., Bandelt, H.-J., Passarino, G., McElreavey, K., and Santachiara-Benerecetti, A.S. 1999. Genetic evidence of an early exit of Homo Sapiens sapiens from Africa through eastern Africa. Nature Genetics 23:437-441.
Schwarcz, H.P., Blackwell, B., Goldberg, P., and Marks, A.E. 1979. Uranium series dating of travertine from archaeological sites, Nahal Zin, Israel. Nature 277:558-560.
Saturday, April 21, 2007
Sunday, April 1, 2007
Parental Selection, Human Hairlessness, and Skin Color
Judith Rich Harris, known for her writings on child psychology (No Two Alike: Human Nature and Human Individuality), has just published an article on the evolution of hairlessness and lighter skin color in humans through "parental selection." She begins with the words of a !Kung woman who decides against killing her newborn daughter: “I don't want to kill her. This little girl is too beautiful. See how lovely and fair her skin is?”
Infanticide is common among the !Kung, especially if the youngest child has not been weaned yet, but the decision is never made lightly and arbitrary factors—such as a cute physical appearance—can make the difference between life and death. This is what Harris calls "parental selection." The decision to kill or not to kill often lies at a tipping point where extraneous factors can push the balance one way or the other. Over time, especially given the prevalence of infanticide in most human cultures, such factors may have eventually altered the appearance of children and even adults, making our skin less hairy, smoother, and fairer in color.
There remains, of course, the question as to why less hairy, smoother, and fairer skin is cute. Harris attributes the reason to culture: "Once the notion that “hairlessness is us, hairiness is them” became part of the culture of a group of hominids, then sexual selection plus parental selection could have eliminated hairiness very quickly. Any infant born too hairy would have elicited an “ugh” response; in all likelihood, it would have been killed or abandoned at birth."
Fine. But is the "ugh" response something we learn from our culture? Doesn't it exist in other animals? Animals that don't have culture? And why would culture predispose us to reject hairy, rough, and dark skin? Because such skin is "ugh"?
This sounds like a circular argument. Yes, culture may strengthen the "ugh" response by telling us whether others feel the same way, either directly through conversation or indirectly through songs, tales, and the very words we use—all of which continually remind us what is "ugh" and what isn't. But the response itself needs neither words nor a human mind. It exists in other animals. Birds do it, bees do it.
This differentiation between "ugh!" and "cute!" has been shown in non-human primates, particularly when they judge the physical appearance of infants. Jay (1962:472-473) notes:
The coat color of the newborn infant of all species of Old World monkeys for which information is available is different from that of an adult of the same species. Often this difference is extremely striking, as in the dark-brown fur of the newborn langur. Skin color of the infant langur, baboon, and macaque is pink, in contrast to the almost black skin of the older infant or adult. The infant’s pink face, hands, and feet and its large pink ears are in sharp contrast to its dark brown fur. The natal coat color is present during the first two or three months of life, when the infant most needs protection and nourishment from its mother and older monkeys. … As the infant’s coat changes to white and it becomes more and more independent of its mother, the interest of adult females decreases and they no longer seek out the infant to hold and groom it as often as they did when it was smaller, younger, and brown.
Infant fur is the primary releaser of these positive adult responses, apparently because it covers most of the body surface. Infant skin (in particular its pink color) seems to be a secondary releaser (Jay 1962:472-473; Alley 1980:418-419). As juvenile dependence progressively lengthened in ancestral humans, infant skin might have proved more effective than infant fur in stimulating adult care after weaning. For whatever reason, if skin had edged out fur in the child's struggle for adult attention, there would have been selection to project this visual cue more effectively, i.e., by increasing the hair-free portion of the body surface. This in turn would have increased its visual importance. Result: runaway selection for more and more naked skin.
Parental and sexual selection might then have extended the denuding process to adults. Or maybe not. Any selection for infants and juveniles with hair-free skin would inevitably have spilled over onto older age groups … unless there was selection for adults with hairy skin. Perhaps no such balancing selection existed. Or perhaps it wasn't strong enough.
On this subject, Judith Harris raises an interesting point: human hairlessness appeared very late in human evolution. Neanderthals seem to have adapted very well to subzero climates without the benefit of tailored clothing. Both needles and the human body louse (which lives in clothing) seem to date back no earlier than 50,000 years ago, i.e. the transition from Neanderthals to modern humans. Conclusion: body fur must have persisted until this transition, as probably did many other ape-like traits. Even the Neanderthal brain was much more ape than human. It was big, but only because it had to stockpile so many problem-specific and situation-specific algorithms. The quantum leap to general intelligence had not been made. Not yet.
If you could meet a Neanderthal face to face, you wouldn't think it was human. It would look like a big ape. Nor would its behavior change your initial impression.
This conclusion may seem startling. As Mrs. Harris points out: "Paintings and exhibits on human evolution often feature a line-up of increasingly humanlike creatures, starting from some apish ancestor, progressing through Homo habilis and Homo erectus, and ending up triumphantly at Homo sapiens." In fact, human evolution was not a straight line running from early hominids to modern humans. It was more like a logarithmic curve, with most of the big changes taking place recently … in the past 200,000 years. Our hominid ancestors were not man-apes. They were simply apes who stood a bit more erect and handled tools a bit better than do today's apes. Only hindsight makes us see their evolutionary potential.
This leads to an even more startling conclusion: the appearance of Homo sapiens was not a culmination of human evolution. It was a beginning. Such a view has recently gained support from a presentation by Gregory Cochran and John Hawks to the American Association of Physical Anthropologists. The two authors argue that "the origin of modern humans was a minor event compared to more recent evolutionary changes." The pace of evolution actually seems to have accelerated after the transition to modern humans.
References
Alley, T.R. (1980). “Infantile colouration as an elicitor of caretaking behaviour in Old World primates,” Primates 21:416-429.
Harris, J. R. (2006). Parental selection: A third selection process in the evolution of human hairlessness and skin color. Medical Hypotheses, 66: 1053-1059.
Harris, J. R. (2006). No Two Alike: Human Nature and Human Individuality. W.W. Norton, ISBN 978-0-393-05948-9
Jay, P.C. (1962). “Aspects of maternal behavior among langurs,” Annals of the New York Academy of Sciences 102:468-476.
Infanticide is common among the !Kung, especially if the youngest child has not been weaned yet, but the decision is never made lightly and arbitrary factors—such as a cute physical appearance—can make the difference between life and death. This is what Harris calls "parental selection." The decision to kill or not to kill often lies at a tipping point where extraneous factors can push the balance one way or the other. Over time, especially given the prevalence of infanticide in most human cultures, such factors may have eventually altered the appearance of children and even adults, making our skin less hairy, smoother, and fairer in color.
There remains, of course, the question as to why less hairy, smoother, and fairer skin is cute. Harris attributes the reason to culture: "Once the notion that “hairlessness is us, hairiness is them” became part of the culture of a group of hominids, then sexual selection plus parental selection could have eliminated hairiness very quickly. Any infant born too hairy would have elicited an “ugh” response; in all likelihood, it would have been killed or abandoned at birth."
Fine. But is the "ugh" response something we learn from our culture? Doesn't it exist in other animals? Animals that don't have culture? And why would culture predispose us to reject hairy, rough, and dark skin? Because such skin is "ugh"?
This sounds like a circular argument. Yes, culture may strengthen the "ugh" response by telling us whether others feel the same way, either directly through conversation or indirectly through songs, tales, and the very words we use—all of which continually remind us what is "ugh" and what isn't. But the response itself needs neither words nor a human mind. It exists in other animals. Birds do it, bees do it.
This differentiation between "ugh!" and "cute!" has been shown in non-human primates, particularly when they judge the physical appearance of infants. Jay (1962:472-473) notes:
The coat color of the newborn infant of all species of Old World monkeys for which information is available is different from that of an adult of the same species. Often this difference is extremely striking, as in the dark-brown fur of the newborn langur. Skin color of the infant langur, baboon, and macaque is pink, in contrast to the almost black skin of the older infant or adult. The infant’s pink face, hands, and feet and its large pink ears are in sharp contrast to its dark brown fur. The natal coat color is present during the first two or three months of life, when the infant most needs protection and nourishment from its mother and older monkeys. … As the infant’s coat changes to white and it becomes more and more independent of its mother, the interest of adult females decreases and they no longer seek out the infant to hold and groom it as often as they did when it was smaller, younger, and brown.
Infant fur is the primary releaser of these positive adult responses, apparently because it covers most of the body surface. Infant skin (in particular its pink color) seems to be a secondary releaser (Jay 1962:472-473; Alley 1980:418-419). As juvenile dependence progressively lengthened in ancestral humans, infant skin might have proved more effective than infant fur in stimulating adult care after weaning. For whatever reason, if skin had edged out fur in the child's struggle for adult attention, there would have been selection to project this visual cue more effectively, i.e., by increasing the hair-free portion of the body surface. This in turn would have increased its visual importance. Result: runaway selection for more and more naked skin.
Parental and sexual selection might then have extended the denuding process to adults. Or maybe not. Any selection for infants and juveniles with hair-free skin would inevitably have spilled over onto older age groups … unless there was selection for adults with hairy skin. Perhaps no such balancing selection existed. Or perhaps it wasn't strong enough.
On this subject, Judith Harris raises an interesting point: human hairlessness appeared very late in human evolution. Neanderthals seem to have adapted very well to subzero climates without the benefit of tailored clothing. Both needles and the human body louse (which lives in clothing) seem to date back no earlier than 50,000 years ago, i.e. the transition from Neanderthals to modern humans. Conclusion: body fur must have persisted until this transition, as probably did many other ape-like traits. Even the Neanderthal brain was much more ape than human. It was big, but only because it had to stockpile so many problem-specific and situation-specific algorithms. The quantum leap to general intelligence had not been made. Not yet.
If you could meet a Neanderthal face to face, you wouldn't think it was human. It would look like a big ape. Nor would its behavior change your initial impression.
This conclusion may seem startling. As Mrs. Harris points out: "Paintings and exhibits on human evolution often feature a line-up of increasingly humanlike creatures, starting from some apish ancestor, progressing through Homo habilis and Homo erectus, and ending up triumphantly at Homo sapiens." In fact, human evolution was not a straight line running from early hominids to modern humans. It was more like a logarithmic curve, with most of the big changes taking place recently … in the past 200,000 years. Our hominid ancestors were not man-apes. They were simply apes who stood a bit more erect and handled tools a bit better than do today's apes. Only hindsight makes us see their evolutionary potential.
This leads to an even more startling conclusion: the appearance of Homo sapiens was not a culmination of human evolution. It was a beginning. Such a view has recently gained support from a presentation by Gregory Cochran and John Hawks to the American Association of Physical Anthropologists. The two authors argue that "the origin of modern humans was a minor event compared to more recent evolutionary changes." The pace of evolution actually seems to have accelerated after the transition to modern humans.
References
Alley, T.R. (1980). “Infantile colouration as an elicitor of caretaking behaviour in Old World primates,” Primates 21:416-429.
Harris, J. R. (2006). Parental selection: A third selection process in the evolution of human hairlessness and skin color. Medical Hypotheses, 66: 1053-1059.
Harris, J. R. (2006). No Two Alike: Human Nature and Human Individuality. W.W. Norton, ISBN 978-0-393-05948-9
Jay, P.C. (1962). “Aspects of maternal behavior among langurs,” Annals of the New York Academy of Sciences 102:468-476.
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