The Accidental Species: Misunderstandings of Human Evolution

by Henry Gee

4 J. Conard, “Palaeolithic ivory sculptures from southwestern Germany and the origins of figurative art,” Nature 426 (2003): 830–832.

  5 Although the recent news story about a Jewish religious court that sentenced a dog to death by stoning was, apparently, a hoax. http://newsfeed.time.com/2011/06/18/shocking-sentence-jewish-court-condemns-dog-to-death-by-stoning/, accessed 6 November 2012.

  6 I first found this story in Felipe Fernández-Armesto, So You Think You’re Human? A Brief History of Humankind (Oxford: Oxford University Press, 2004).

  CHAPTER 7

  1 M. Srinivasan and A. Ruina, “Computer optimization of a minimal biped model discovers walking and running,” Nature 439 (2006): 72–75.

  2 W. E. H. Harcourt-Smith and L. C. Aiello, “Fossils, feet and the evolution of human bipedal locomotion,” Journal of Anatomy 204 (2004): 403–416; D. L. Gebo, “Climbing, brachiation, and terrestrial quadrupedalism: Historical precursors of hominid bipedalism,” American Journal of Physical Anthropology 101 (1996): 55–92; C. O. Lovejoy, “Evolution of human walking,” Scientific American, November 1988, 118–125.

  3 K. D. Hunt, “The evolution of human bipedality: Ecology and functional morphology,” Journal of Human Evolution 26 (1994): 183–202.

  4 P. E. Wheeler, “The thermoregulatory advantages of hominid bipedalism in open equatorial environments: The contribution of increased convective heat loss and cutaneous evaporative cooling,” Journal of Human Evolution 21 (1991): 107–115; P. E. Wheeler, “The evolution of bipedality and loss of functional body hair in hominids,” Journal of Human Evolution 13 (1984): 91–98.

  5 E. Morgan, The Aquatic Ape Hypothesis (London: Souvenir Press, 1997).

  6 Neil H. Shubin of the University of Chicago told me a story about a drive in Morocco, during which he and the other passengers noticed a tree in the distance that had been colonized by what looked like large birds. Vultures, maybe? As they got closer, it became clear that the birds were in fact a herd of goats that filled the entire tree from the trunk to the outermost twigs.

  7 J. Diamond, The Rise and Fall of the Third Chimpanzee (London: Random House, 1991); J. Diamond, Why Is Sex Fun? The Evolution of Human Sexuality (London: Weidenfeld and Nicolson, 1997).

  8 M. Andersson and Y. Iwasa, “Sexual selection,” Trends in Ecology and Evolution 11 (1996): 53–58; J. Maynard Smith, “Theories of sexual selection,” Trends in Ecology and Evolution 6 (1991): 146–151.

  9 W. D. Hamilton and M. Zuk, “Heritable true fitness and bright birds: A role for parasites?,” Science 218 (1982): 384–387.

  10 R. A. Fisher, The Genetical Theory of Natural Selection (Oxford: Clarendon Press, 1930).

  11 A. Zahavi, “Mate selection: A selection for a handicap,” Journal of Theoretical Biology 53 (1975): 205–214.

  12 At this point you will ask yourself why expensive sports cars are seen as sexy, whereas more inexpensive and practical station wagons are not. Or are they? Advertisers, as we have seen, are very good instinctive judges of human motivation—so how would a copywriter sell the idea of station wagons to men of a certain age and maturity who still hanker after that red sports car? One answer—I forget the particular campaign—went like this. A man was pictured alongside his beautiful girlfriend in a snappy red roadster. In the next panel, the same man was pictured next to the same beautiful woman, now his adoring wife, in a station wagon full of children and other appurtenances of middle-aged success—dogs, sports equipment, and so on. The caption went something like this: Sports cars are full of the empty show of youth. But now you’ve got the girl, fathered all these children, and achieved some status, you have obviously proved your virility. You will therefore need a suitable vehicle in which to display the fruits of your loins and your material acquisitions to males in sports cars, who have yet to achieve alpha-male dominance status.

  13 The following paper links sex with bipedality, though the thesis is much more complicated than mine: S. T. Parker, “A sexual selection model for hominid evolution,” Human Evolution 2 (1987): 235–253.

  14 F. Szalay and R. K. Costello, “Evolution of permanent estrus displays in hominids,” Journal of Human Evolution 20 (1991): 439–464.

  15 L. Benshoof and R. Thornhill, “The evolution of monogamy and concealed ovulation in humans,” Journal of Social and Biological Structures 2 (1979): 95–106.

  16 H. Greiling and D. M. Buss, “Women’s sexual strategies: The hidden dimension of extra-pair mating,” Personality and Individual Differences 28 (2000): 929–963. In his book The Rise and Fall of the Third Chimpanzee, Jared Diamond relates an anecdote about the prevalence of extra-pair paternity related by an obstetrician. Basically, there’s very much more of it than people either claim or are prepared to admit, given that the social norm is the maintenance of overt monogamy.

  17 L. Bellamy and A. Pomiankowski, “Why promiscuity pays,” Nature 479 (2011): 184–186; C. K. Cornwallis et al., “Promiscuity and the evolutionary transition to complex societies,” Nature 466 (2010): 969–972; D. F. Westneat and I. R. Stewart, “Extra-pair paternity in birds: Causes, correlates, and conflict,” Annual Review of Ecology, Evolution and Systematics 34 (2003): 365–396; S. C. Griffith et al., “Extra-pair paternity in birds: A review of interspecific variation and adaptive function,” Molecular Ecology 11 (2002): 2195–2212; M. Petrie and B. Kempenaers, “Extra-pair paternity in birds: Explaining variation between species and populations,” Trends in Ecology and Evolution 13 (1998): 52–58.

  18 D. R. Rubenstein and I. J. Lovette, “Reproductive skew and selection on female ornamentation in social species,” Nature 462 (2009): 786–789.

  19 Nature, along with most other scientific journals these days, receives submissions online. It was not always so. I well remember the days when manuscripts arrived in the mail, and in quadruplicate, together with any supporting information, so that the office would have a copy, and there’d be one each for up to three potential referees. One day I received a huge parcel, containing a somewhat way-out manuscript on the origin of human secondary sexual characteristics. The author’s thesis was supported by a particularly lurid example of what used to be called “men’s magazines.” There were four copies of this, too. I swear that I sent all of them back to the author. If it’s in an archive somewhere, I’m not aware of it. Honest.

  20 A. S. Jackson et al., “The effect of sex, age and race on estimating percentage body fat from body mass index: The Heritage Family Study,” International Journal of Obesity 26 (2002): 789–796.

  21 P. Frost, Fair Women, Dark Men: The Forgotten Roots of Racial Prejudice (Christchurch, New Zealand: Cybereditions, 2005).

  22 D. W. Yu and G. H. Shepard, “Is beauty in the eye of the beholder?,” Nature 396 (1998): 321–322.

  23 D. R. Rubenstein and I. J. Lovette, “Reproductive skew and selection on female ornamentation in social species,” Nature 462 (2009): 786–789.

  24 F. D. Wyatt, “Fifty years of pheromones,” Nature 457 (2009): 262–263.

  25 Note that I didn’t write “nobody.” We humans can get turned on by the most peculiar things. For example, a friend of a friend reportedly sells rubber Wellington boots online to an eager market of fetishists; and it remains unknown, at least to me, why so many women of my acquaintance are so enraptured by, of all things, shoes.

  26 See for example S. Dagenais et al., “A systematic review of low back pain cost of illness studies in the United States and internationally,” Spine Journal 8 (2008): 8–20.

  27 K. K. Whitcome et al., “Fetal load and evolution of lumbar lordosis in bipedal hominins,” Nature 450 (2007): 1075–1078.

  28 For a review see D. Lieberman, The Evolution of the Human Head (Cambridge, MA: Harvard University Press, 2011).

  29 C. O. Lovejoy et al., “The pelvis and femur of Ardipithecus ramidus: The emergence of upright walking,” Science 326 (2009): 71, 71e1–71e6.

  30 C. V. Ward, “Interpreting the posture and locomotion of Australopithecus afarensis: Where do we stand?,” in “Yearbook of Physical Anthropology,”
supplement, American Journal of Physical Anthropology 119, suppl. 35 (2002): 185–215.

  31 D. M. Bramble and D. E. Lieberman, “Endurance running and the evolution of Homo,” Nature 432 (2004): 345–352.

  32 L. Rook et al., “Oreopithecus was a bipedal ape after all: Evidence from the iliac cancellous architecture,” Proceedings of the National Academy of Sciences of the USA 96 (1999): 8795–8799; S. Moyà-Solà et al., “Evidence of hominid-like precision grip capability in the hand of the Miocene ape Oreopithecus,” Proceedings of the National Academy of Sciences of the USA 96 (1999): 313–317.

  33 T. Harrison, “A reassessment of the phylogenetic relationships of Oreopithecus bambolii Gervais,” Journal of Human Evolution 15 (1986): 541–583.

  CHAPTER 8

  1 To use the argument on the illusion of complexity I presented in chapter 3, modern technology proceeds by the combination of parts that individually have become very simple. Yes, you probably could make something that had the processing power of an iPad from vacuum tubes—but it would be enormous, incredibly expensive, shockingly unreliable, and wildly inefficient.

  2 R. Wrangham, Catching Fire: How Cooking Made Us Human (London: Profile Books, 2009); L. C. Aiello and P. Wheeler, “The expensive-tissue hypothesis: The brain and the digestive system in human and primate evolution,” Current Anthropology 36 (1995): 199–221.

  3 A well-known phenomenon is the social facilitation of eating, in which people tend to eat more when in company than when dining alone. See for example V. I. Clendenen et al., “Social facilitation of eating among friends and strangers,” Appetite 23 (1994): 1–13. Many years ago I wrote an account of this paper, or one very like it, as an excuse to tell a favorite joke. “Have another bagel, rabbi,” says the hostess. “I couldn’t possibly,” says the rabbi, “I’ve already had three.” “You’ve had four,” the hostess replies, “but who’s counting?”

  4 T. Taylor, The Artificial Ape: How Technology Changed the Course of Human Evolution (New York: Palgrave Macmillan, 2010).

  5 W. B. Arthur, The Nature of Technology: What It Is and How It Evolves (London: Allen Lane, 2009).

  6 J. Bradshaw, In Defence of Dogs: Why Dogs Need Our Understanding (London: Allen Lane, 2011); P. Shipman, The Animal Connection: A New Perspective on What Makes Us Human (New York: W. W. Norton, 2011).

  7 J. Diamond, “The double puzzle of diabetes,” Nature 423 (2003): 599–602.

  8 S. Semaw et al., “2.5-million-year-old stone tools from Gona, Ethiopia,” Nature 385 (1997): 333–336; S. P. McPherron et al., “Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia,” Nature 466 (2010): 857–860.

  9 See for example G. R. Hunt, “Manufacture and use of hook-tools by New Caledonian crows,” Nature 379 (1996): 249–251.

  10 A. Whiten, “The second inheritance system of chimpanzees and humans,” Nature 437 (2005): 52–55.

  11 M. Haslam et al., “Primate archaeology,” Nature 460 (2009): 339–344.

  12 This discussion throws a whole new light on the words to that otherwise utterly infuriating song “There’s a Hole in My Bucket, Dear Henry.”

  13 See for example A. H. Taylor et al., “Do New Caledonian crows solve physical problems through causal reasoning?,” Proceedings of the Royal Society of London B 276 (2009): 247–254; A. H. Taylor et al., “Complex cognition and behavioural innovation in New Caledonian crows,” Proceedings of the Royal Society of London B 277 (2010): 2637–2643; A. H. Taylor et al., “Context-dependent tool use in New Caledonian crows,” Biology Letters (2011), doi:10.1098/rsbi.2011.0782.

  14 The New Caledonian crow, for example, has a large brain relative to its size, even compared with other crow species. See J. Cnotka et al., “Extraordinary large brains in tool-using New Caledonian crows (Corvus moneduloides),” Neuroscience Letters 433 (2008): 241–245; J. Mehlhorn et al., “Tool-making New Caledonian crows have large associative brain areas,” Brain, Behaviour and Evolution 75 (2010): 63–70.

  15 C. J. Lepre et al., “An earlier origin for the Acheulian,” Nature 477 (2011): 82–85.

  16 G. Sharon, “Acheulian giant-core technology: A worldwide perspective,” Current Anthropology 50 (2009): 335–367; S. J. Lycett et al., “Acheulean variability and hominin dispersals: A model-bound approach,” Journal of Archaeological Science 35 (2008): 553–562.

  17 T. Wynn, “Handaxe enigmas,” World Archaeology 27 (1995): 10–24; J. C. Whittaker and G. McCall, “Handaxe-hurling hominids: An unlikely story,” Current Anthropology 42 (2001): 566–572.

  18 S. Mithen, “Handaxes: The first aesthetic artefacts,” in E. Voland and K. Grammer, eds., Evolutionary Aesthetics (Berlin: Springer-Verlag, 2003), 261–274; A. J. Machin et al., “Why are some handaxes symmetrical? Testing the influence of handaxe morphology on butchery effectiveness,” Journal of Archaeological Science 34 (2007): 883–893.

  19 A. Kohn and S. Mithen, “Handaxes: Products of sexual selection?,” Antiquity 73 (1999): 518–526. See also the counterargument—A. Nowell and M. L. Chang, “The case against sexual selection as an explanation for handaxe morphology,” PaleoAnthropology (2009): 77–88.

  20 F. Berna et al., “Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa,” Proceedings of the National Academy of Sciences of the USA 109 (2012): 7593–7594.

  21 A. Brumm et al., “Hominins on Flores, Indonesia, by one million years ago,” Nature 464 (2010): 748–752.

  22 C. Dean et al., “Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins,” Nature 414 (2001): 628–631; H. Coqueugniot et al., “Early brain growth in Homo erectus and implications for cognitive ability,” Nature 431 (2004): 299–302.

  23 P. Mellars, “Neanderthals and the modern human colonization of Europe,” Nature 432 (2004): 461–465.

  24 B. Wood, “Origin and evolution of the genus Homo,” Nature 355 (1992): 783–790; H. M. McHenry and K. Coffing, “Australopithecus to Homo: Transformations in body and mind,” Annual Review of Anthropology 29 (2000): 125–146.

  25 B. Wood and M. Collard, “The human genus,” Science 284 (1999): 65–71.

  26 B. Asfaw et al., “Australopithecus garhi: A new species of early hominid from Ethiopia,” Science 284 (1999): 629–635; L. Berger et al., “Australopithecus sediba: A new species of Homo-like australopith from South Africa,” Science 328 (2010): 195–204.

  CHAPTER 9

  1 University of Cambridge, Research News, http://www.cam.ac.uk/research/news/the-bird-tango-cambridge-academic-fuses-love-of-birds-and-dance/, accessed 12 April 2012.

  2 For example, this clip narrated by David Attenborough, from BBC Worldwide, http://www.youtube.com/watch?v=BGPGknpq3e0, accessed 12 April 2012.

  3 J. M. Dally et al., “Food-caching western scrub-jays keep track of who was watching when,” Science 312 (2006): 1662–1665; C. R. Raby et al., “Planning for the future by western scrub-jays,” Nature 445 (2007): 919–992; N. J. Emery and N. S. Clayton, “Effects of experience and social context on prospective caching strategies by scrub jays,” Nature 414 (2001): 443–446.

  4 N. J. Emery and N. S. Clayton, “Comparing the complex cognition of birds and primates,” in L. J. Rogers and G. Kaplan, eds., Comparative Vertebrate Cognition: Are Primates Superior to Non-Primates? (New York: Kluwer Academic/Plenum, 2004), 3–56.

  5 N. J. Emery, “Cognitive ornithology: The evolution of avian intelligence,” Philosophical Transactions of the Royal Society B 361 (2006): 23–43; S. Shultz and R. I. M. Dunbar, “Social bonds in birds are associated with brain size and contingent on the correlated evolution of life-history and increased parental investment,” Biological Journal of the Linnean Society 100 (2010): 111–123; M. J. Burish et al., “Brain architecture and social complexity in modern and ancient birds,” Brain, Behavior and Evolution 63 (2004): 107–124.

  6 H. J. Jerison, “The theory of encephalization,” Annals of the New York Academy of Sciences 299 (1977): 146
–160; H. J. Jerison and H. B. Barlow, “Animal intelligence as encephalization,” Philosophical Transactions of the Royal Society of London B 308 (1985): 21–35.

  7 With the possible exception, I like to think, of the gluteus maximus—the major muscle that forms the mass of the buttocks, essential to our bipedal stance. You may draw whatever conclusion you will from this comparison.

  8 G. P. Rightmire, “Brain size and encephalization in early to mid-Pleistocene Homo,” American Journal of Physical Anthropology 124 (2004): 109–123.

  9 C. B. Ruff et al., “Body mass and encephalization in Pleistocene Homo,” Nature 387 (1997): 173–176.

  10 G. P. Rightmire, “Human evolution in the Middle Pleistocene: The role of Homo heidelbergensis,” Evolutionary Anthropology 6 (1998): 218–227.

  11 H. Thieme, “Lower Palaeolithic hunting spears from Germany,” Nature 385 (1997): 807–810.

  12 R. N. Carmody and R. W. Wrangham, “The energetic significance of cooking,” Journal of Human Evolution 57 (2009): 379–391.

  13 L. C. Aiello and P. Wheeler, “The expensive-tissue hypothesis: The brain and the digestive system in human and primate evolution,” Current Anthropology 36 (1995): 199–221.

  14 A. Navarrete et al., “Energetics and the evolution of human brain size,” Nature 480 (2011): 91–93.

  15 R. Wrangham, Catching Fire: How Cooking Made Us Human (London: Profile Books, 2009).

  16 H. H. Stedman et al., “Myosin gene mutation correlates with anatomical changes in the human lineage,” Nature 428 (2004): 415–418.

  17 D. Lieberman, The Evolution of the Human Head (Cambridge, MA: Harvard University Press, 2011).

  18 K. Hawkes et al., “Grandmothering, menopause, and the evolution of human life histories,” Proceedings of the National Academy of Sciences of the USA 95 (1998): 1336–1339.

  19 P. S. Kim et al., “Increased longevity evolves from grandmothering,” Proceedings of the Royal Society of London B 279 (2012): 4880–4884.

  20 R. Mace and A. Alvergne, “Female reproductive competition within families in rural Gambia,” Proceedings of the Royal Society of London B 279 (2012): 2219–2227.