In The Story of the Human Body Daniel Lieberman builds a strong case that making fully informed decisions about diet and lifestyle is only possible through the lens of evolutionary history. If you want to know where your body comes from, you need to understand its evolutionary history. Why do humans stand and walk on two legs? Why are we weak compared to other primates of comparable size? Why are our legs and feet shaped the way they are, with springy tendons and arched feet? Why does our spine have a special S-curve? The answer to these questions lies in the the evolutionary history of our species.
Now ask, why do people in modern societies suffer from “diseases of affluence” like obesity, type-2 diabetes, tooth decay, metabolic syndrome, flat feet, nearsightedness, lower back pain, and sleep disorders? Daniel Lieberman argues that these questions can only be fully answered by understanding the evolutionary history of our species. Lieberman argues these diseases are examples of “mismatch diseases” i.e. a disease that is primarily caused by our bodies not being sufficiently adapted to novel gene-environment contexts. We know they’re mismatch diseases primarily because they used to be rare, are largely preventable, and are almost unheard of in hunter-gatherer populations.
Lieberman argues that all of these diseases are in some sense a result of cultural evolution speeding ahead of natural evolution with the result that have humans manufactured a psychologically comfy and satisfying environment that is paradoxically unhealthy without fundamentally affecting our reproductive fitness. Lieberman calls this this paradoxical unhealthiness “dysevolution”. It turns out that surrounding ourselves with unlimited sources of cheap junk food is a bad idea because humans are genetically wired to crave food with dense amounts of fat, sugar, starch, and salt.
Lieberman is no luddite, and certainly doesn’t advocate a return to the caves and giving up on modern science and technology. His position is more nuanced than many of the extreme black and white positions out there, as befitting the complexity of gene-environment interaction. In many senses, the agricultural and industrial revolutions have propelled humans to new heights of health and longevity, with modern science curing diseases and fixing people better than ever before. At the same time, we are living longer but spending many of those years suffering from chronic, preventable diseases. The paradox of the modern world is reduced mortality but greater morbidity i.e. living longer, but spending more of those extra years with an illness of some sort. Lieberman argues that too often the incentives of modern medicine aim at fixing symptoms but not the underlying structural causes: the toxically comfortable environments we built for ourselves.
As Steven Pinker observes, the logic of loyalty is particularly clear in the domain of romantic relationships: You’re a great catch, but there is bound to be someone out there who’s got everything you’ve got plus a little more. Knowing that your partner might someday meet such a person, you’d be reassured by the knowledge that your partner isn’t going to leave you as soon as something better comes along. This would make you much more willing to settle down with your partner and start a family–a high-stakes cooperative endeavor if ever there was one. It’s wonderful that your partner fully appreciates your many marketable qualities, but that may not be enough to keep you together. What you really want is for your partner to have a deep, unshakable desire to be with you and you alone. In short, you want your partner to love you, to want you not only for your wonderful qualities but just because you’re you. Only love provides the kind of loyalty you need in order to take the parenting plunge. Thus, love appears to be more than just an intense form of caring. It’s a highly specialized piece of psychological machinery, an emotional straitjacket that enables cooperative parenting by assuring our parenting partners that they won’t be abandoned.
~Joshua Greene, Moral Tribes: Emotion, Reason, and the Gap Between Us and Them (2013), p. 42
A used copy of Stephen J. Gould’s book The Panda’s Thumb (1980) has been sitting on my shelf for a while, and I’m kicking myself for not reading it sooner. What a delightful little book of science essays! Each essay is an edited version of one of his monthly columns at Natural History magazine. Subsequently, the essays are intelligible to the general intelligent reader, but Gould does not thereby sacrifice an appreciation for hard facts and subtle reasoning. Gould makes science come alive with his anecdotes, wry humor, and gentle argumentation about topics ranging from the panda’s thumb to hopeful monsters and everything in between. Nothing is too big or small for Gould to think worthy of writing about. All in all, I highly recommend this book for any student of biology or lover of science.
Filed under Books, Science
Evolutionary biology, and its offspring, sociobiology, are not inherently sexist. The proportion of “sexists” among their proponents is probably no greater than the proportion among scientists generally. To be sure, contemporary analyses of mammalian breeding systems can cause even a committed Darwinian like myself to contemplate her gender with foreboding. Yet, it is all too easy to forget, while quaking, that sociobiology, if read as a prescription for life rather than a description of the way some creatures behave, makes it seem bad luck to be born either sex.
~Sarah Blaffer Hrdy, The Woman That Never Evolved, p. 14
I was driven to understand my past. For we are not ready-made out of somebody’s rib. We are composites of many different legacies, put together from leftovers in an evolutionary process that has been going on for billions of years. Even the endorphins that made my labor pains tolerable came from molecules that humans still share with earthworms.
~Sarah Blaffer Hrdy, Mother Nature: A History of Mothers, Infants, and Natural Selection