The Wild Life of Our Bodies: Predators, Parasites, and Partners That Shape Who We Are Today
Page 32
[*]A list that if mixed, produces nearly all of our favorite foods, from cookies to cakes to cereal, pizza, muffins, pretzels, ice cream, and nearly all the rest.
[*]I know, I said there were four kinds of evidence. The fourth form of evidence is the most equivocal, but also in a way the most interesting. Toxoplasmosis gondii is an incredibly common disease in modern humans. In most adults, it is benign, dormant even, but for the fetuses of pregnant women, it can be deadly. The funny thing about T. gondii is that it is a cat parasite. It cannot complete its life cycle unless it moves from a human (or whatever other temporary host) back into a cat. One wonders why T. gondii bothers infecting humans. Perhaps it is a mistake. Many of us live with cats now, and so pick up T. gondii accidentally, and it does not and has never gained from the interaction. But a second possibility exists, the one I prefer. It is possible that T. gondii moves into humans hoping that we will be eaten by a cat, so predictable was that fate in our long history. Maybe. Maybe not. It seems telling that T. gondii is not the only disease with this life history that infects us. There are several, all waiting for a tiger to eat their human, so that they can mature.
[*]One wonders whether we really had a choice. Could we have constructed another kind of house? Yes. For example, consider the houses of birds who build most of their nests with open tops. They go about, unworried by the rain. Some birds build coverings over nests or build nests in hollow chambers, but they are more the exception than the rule.
[*]Though some fear is hard to shake. Domestic hens, though they may still have things to fear, no longer face much threat from hawks. Yet when a plastic hawk is made to fly above tame chickens and wild fowl, both stop eating and walk alert, alarmed. They recognized the hawk. And so the chicken, like us, has apparently retained some of its specific fears even though in its most common modern condition (in cubicles free of predators and stocked with near infinite food), such fears are misplaced. They are more like us than we might admit, these chickens.
[*]I am reminded of the apparently true story of China’s Chairman Mao and the sparrows. Mao did not like the sparrows of China. They bothered him (as did three other “pests,” mosquitoes, flies, and rats). They shat on his porch and ate valuable seeds. So he did what other man-god rulers might have done; he had everyone in the country go outside into their backyards and beat pots and pans to make noise so that the sparrows would fly in fear. The banging continued for days as the birds hovered, unable to suppress their fear, until they fell dead by the millions, confirming the power of Mao relative to nature. But nature is politically neutral and so the next year, the locusts, once eaten by the sparrows were more abundant than they had ever been. A plague of such magnitude ensued that the fields were quiet except for the sound of chewing. Thousands of people starved. Trying to eradicate nature always bears consequences.
[*]This is true despite the fact that the ancestors of most modern Europeans and Asians had sex with Neanderthals; essentially all Europeans and Asians have Neanderthal genes.
[*]A hint of the course’s flavor may be discerned by a quick look at newspaper articles in which Despommier was mentioned or quoted during those years. “Diseases carried by mosquitoes are a leading cause of death.” “Rise in international travel helps viruses cross borders.” “Contaminated food makes millions ill despite advances.” “West Nile virus found in organ recipient.” You get the picture.
[*]The five were Doug Larson, Uta Matthes, Peter E. Kelly, Jeremy Lundholm, and John Gerrath.
[*]The list of species familiar to our everyday landscapes that originally lived on cliffsides or talus slopes is incredible and bears trotting out a little further—there are, on this list, tulips, geraniums, forsythias, dandelions, peonies, petunias, and then even goats, guinea pigs, and nearly all of our domestic crops, from capers and agaves to almonds, carrots, cucumbers, and even wheat.