Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live by Marlene Zuk Read Free Book Online Page A

disturbingly, or at least oddly, the former rocker Ozzy Osbourne attributes his survival of past excesses, such as drinking “up to four bottles of Cognac a day,” according to the Daily Mail , to having Neandertal genes, a discovery he purportedly made with the help of a private genetics company. 29 )
    Since the Neandertals themselves, along with other now-extinct forms of humans in our direct lineage, are no longer around to tell us what they were like, we have to use what they left behind, in the form of tools, the remains of the animals they ate, and their own bodies, to understand the lives of our ancestors. How much can we conclude from these traces of bone and rock, and what do they tell us about where we came from?
    Even just a fragment of skull can provide enormous amounts of information about the brain and body it was once part of. Any fan of the television show CSI knows that approximate age, height, and sex can be extrapolated from part of a skeleton, but modern anthropologists can easily outdo such fiction in their detective abilities. For example, the Neandertal brain, while about as large as that of a modern-day human, is shaped differently: it is more elongated and lacks the front bulge apparent in humans. Researchers at the Max Planck Institute for Evolutionary Anthropology in Germany closely examined the skulls of a Neandertal newborn baby and one older infant. The younger skull had a somewhat elongated braincase, like that of a human newborn, but the older Neandertal baby skull had not begun rounding in the areas at the top and base—the feature that gives human skulls their distinctive appearance. The researchers concluded that the Neandertals, even with their big brains, had a different trajectory of brain development than modern humans have, which could mean that our unique capabilities are a product of very early developmental processes. 30 In other words, it’s not just the parts you have, but how they came to be, that determines your behavior. Other scientists are not convinced, given the scanty set of bones used for analysis, but regardless of the claim itself, the studies point to the amazingly detailed reconstructions that can be made using just a few bits of bone.
    Teeth have long been used to draw inferences about diet, but recent developments in the analysis of dental enamel itself are providing an exciting new way to determine what our ancestors’ diets were like. It’s a rather more benign version of the idea that, when you have sex, you’re also having sex with all of your partner’s previous partners. When it comes to food, your teeth reflect not only the types of plants you eat, but the plants that the animals you eat ate themselves. Different kinds of plants use different kinds of carbon in their transformation of sunlight into energy, and those carbon variants can be tracked in the tooth enamel of animals, with trees and shrubs having a different chemical signature than grasses and sedges have. Anthropologists Matt Sponheimer and Julia Lee-Thorp examined the teeth of Australopithecus africanus and found evidence of appreciable amounts of the grass and sedge type of carbon, suggesting that these hominins ate seeds, roots, and tubers, and also could have eaten grazing animals. 31 They did not necessarily hunt big game; scavenging or eating insects like beetle larvae could have had the same result. Nonetheless, the study illustrates how much data can be gleaned from indirect sources.
    What about reconstructing not brain growth or other aspects of anatomical evolution, but ancestral behavior? Here, too, fossils have played a role, but the extrapolation is a bit riskier.
    “Neanderthals Really Were Sex-Obsessed Thugs,” blared a 2010 headline from the UK newspaper the Telegraph , 32 and others were quick to follow, with AFP cheerfully noting, “Neanderthals Had a Naughty Sex Life, Unusual Study Suggests.” 33 Neandertals were not the only subject of the study in question, but as I