The Wild Life of Our Bodies: Predators, Parasites, and Partners That Shape Who We Are Today

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The Wild Life of Our Bodies: Predators, Parasites, and Partners That Shape Who We Are Today Page 27

by Rob Dunn


  Harry Greene, Lynne Isbell, Geerat Vermeij, Joel Weinstock, Philip Trexler, Sarah Tishkoff, Dickson Despommier, Mark Schaller, Corey Fincher, Randy Thornhill, and Markus Rantala all generously read the chapters relating to their research and added both insight and detail. They also contributed the research that in the first place helped me to see elements of who we were and are. Maurice Pollard, Philip Trexler, Joanna Lambert, and Piotr Naskrecki spent time talking me through some of their work and also their thoughts on the relationships between the rest of life and humans. William Parker read the entire book more than once and, in doing so, became immersed in even more of the mysteries of who we are than he was before. Read Dunn, Gregor Yanega, John Godwin, Nick Haddad, Diane Dunn, John Dunn, Liz Krachey, Matthew Krachey, Michael Gavin, Jen Solomon, Philip Carter, Piotr Naskrecki, Melissa Mchale, Will Wilson, Craig Sullivan, Robert Anholt, John Vandenberg, Bob Grossfeld, Nash Turley, Marc Johnson, Cherry Crayton, and Kevin Gross all read parts or in most cases all of the book and provided valuable comments and insight.

  I am thankful to Sean Menke, Benoit Guenard, Neil McCoy, Shannon Pelini, Mike Weiser, Nyeema Harris, Judith Canner, Sarah Diamond, Andrea Lucky, Jiri Hulcr, Magdalena Sorger, and other folks in my lab who know that when they knock at my door and no one answers, even when they hear typing, they should come back later. Damian Shea and Thurman Grove supported my writing as a form of an extension, another way to put, if not a person, some words out into each of the counties of North Carolina. I am especially grateful to Victoria Pryor, without whose help this book would be less rich and interesting and, in fact, might not exist at all. Elisabeth Dyssegaard and Bill Strachan edited this book into being. Thanks to my sister Jane, for spending a childhood with me out in the woods pretending to live as we all once lived, foraging for food and making our tools from what we found—at least for the few hours before our mom called us in.

  And, of course, thanks to Lula and Goose for being Lula and Goose and, in doing so, reminding me just how fortunate we are to have our one wild life.

  Thank you to Monica for saying yes in the back of a pickup truck near Esperanza in the Bolivian Amazon. What fun we’re having with this twisting jungle ride.

  Notes

  1: The Origins of Humans and the Control of Nature

  1. That first moment is muddied in a kind of anthropological Abbot and Costello routine about who was on first and what counts as discovery, but the very first tooth was actually found by Gen Suwa of the University of Tokyo.

  2. Older sets of bones had been found, including a 6-million-year-old skull from Chad, but none of them was more than small fragments of bodies and stories. There is only so much one can extrapolate from a single disembodied head.

  3. In fact, hominid fossils have been discovered from no fewer than fourteen different time intervals at or near Aramis.

  4. The paper, titled “Australopithecus ramidus, a New Species of Early Hominid from Aramis, Ethiopia” by Tim White along with Gen Suwa at the University of Tokyo and Berhane Asfaw in the Ministry of Culture and Sports Affairs in Ethiopia appeared in the scientific journal Nature (371: 306–308). In this paper, what we now know as Ardipithecus ramidus was called Australopithecus ramidus, in other words, a new species of an already known genus. The novelty of the find was not yet totally clear. The name ramidus comes from the local Afar language in which ramid means “root,” whether of a plant or a people.

  5. Shreeve, J. June, 2010. The Evolutionary Road. National Geographic. http://ngm.nationalgeographic.com/2010/07/middle-awash/shreeve-text/1.

  6. In part, the question of which find represents the “earliest” human ancestor relates more to the parsing of language than to science. The earliest ancestor of humans was a single-celled microbe. What White and others mean when they discuss the “earliest human ancestor” is the first species to be more human than ape.

  2: When Good Bodies Go Bad (and Why)

  1. Gumpert, M. March 22, 1953. We Can Live Longer—But for What? New York Times.

  2. Predicting and even measuring life expectancies is notoriously difficult, but at least some projections suggest declining life expectancies in Western countries in the years to come. See, for example, Olshansky, S. Jay; Passaro, Douglas J.; Hershow, Ronald C.; Layden, Jennifer; Carnes, Bruce A.; Brody, Jacob; Hayflick, Leonard; Butler, Robert N.; Allison, David B.; Ludwig, David S. 2005. A Potential Decline in Life Expectancy in the United States in the 21st Century. New England Journal of Medicine 352: 1138–1145.

  3. Regardless of whether or not there is something to Hugot’s theory, the idea that there is a specific suite of microbes that live in all our refrigerators and in refrigeration trucks and, more generally, in the connected world of cold spaces housing our food, is uncontested. They are there, dividing by the trillions each day and evolving to be a more and more prominent part of modern life, a kind of miniature Arctic, replete with food supplies. Although humans have been putting things on ice for thousands of years, the first refrigerator was not built in the United States until 1875. Rather suddenly, we shifted from eating our food relatively fresh to eating our food whenever it suited us. By 1930, millions of people in the United States owned refrigerators. Far from being “sterile,” our refrigerators are full of the particular kinds of life that in fact do well in cold. When the fridge light goes off, dozens of types of bacteria, fungi, and other kinds of life actually thrive. Among the bacteria are species of Listeria, a potentially deadly pathogen, but also many species about which essentially nothing is known. It is because of these cold-tolerant and even cold-loving species that there is a “best by” date on your milk. We are, as we change the world, creating all sorts of new habitats into which life is shifting, whether we like it or not, forming new species and living new ways.

  4. So firmly was this hypothesis believed that some patients were given frontal lobotomies. This happened horrifyingly recently. A study in 1956 reported the results of lobotomies on six patients who were suffering from both psychological problems and, independently, Crohn’s disease. The intestinal problems of three patients got better (chance would predict that three would get better and three worse). Two patients died. The experiment was viewed as a success.

  5. E-mail from J.V. Weinstock, May 18, 2009.

  6. Vaughan, T. A. 1986. Mammalogy. 3rd ed. New York: Harcourt Brace Jovanovich College Publishers.

  7. Bucky and other details of the Byerses’ lives and study of pronghorn come from e-mails from John Byers and his lovely book Built for Speed, a Year in the Life of Pronghorn. 2003. Cambridge, Mass.: Harvard University Press.

  8. Here he is quoting Willa Cather, who wrote, “Elsewhere the sky is the roof of the world; but here the earth was the floor of the sky,” in Death Comes for the Archbishop.

  9. For example, see Lindstedt, S. L.; Hokanson, J. F.; Wells, D. J.; Swain, S. D.; Hoppeler, H.; and Navarro, V. 1991. Running Energetics in the Pronghorn Antelope. Nature 353: 748–750.

  10. Mammal biologists love to catalogue deaths of their study organisms. For baby pronghorn, see Beale, D. M., and Smith, A. D. 1973. Mortality of Pronghorn Antelope Fawns in Western Utah. Journal of Wildlife Management 37: 343–352, in which about one in four fawns were eaten by bobcats.

  11. This “cheetah” is actually unrelated to the African cheetah. Research by Barnett and colleagues shows that the American cheetah is most closely related to the cougar. The American cheetah evolved traits similar to those of the African cheetah—including elongated limbs, enlarged nasal passages, and claws that do not retract—independently. These African and American cheetahs are an example of convergent evolution, wherein two species evolve similar traits in response to similar conditions. The conditions in this case were the expansion of grasslands and with them, the evolution of species like the pronghorn or its convergent African analogue, the antelope, both of which avoid predators by fleeing at high speeds. Barnett, R.; Phillips, M. J.; Martin, L. D.; Harington, R.; Leonard, J. A.; and Cooper, A. 2005. Evolution of the Extinct Sabretooths and
the American Cheetah-like Cat. Current Biology 15: R589–R590. doi:10.1016/j.cub.2005.07.052. http://linkinghub.elsevier.com/retrieve/pii/S0960982205008365. Retrieved 2007-06-04.

  12. A recent study by J. J. Dennehey has shown that low-ranking females tend to be forced to the margins of the herd to forage on their own. They are shunned and solitary. Historically, such individuals would have been the most likely to have been eaten, the bad luck of being low on the totem pole. But today, with little threat of predation, those low-ranked individuals actually obtain better quality food than those at the middle of the hierarchy who are safe from nonexistent predation but have to fight for food alongside the very highest ranked individuals. It is conceivable that these realities will, in the long term, affect the evolution of pronghorn social structure and with it, their speed. 2001. Influence of Social Dominance Rank on Diet Quality of Pronghorn Females. Behavioral Ecology 12:177–181.

  13. And slightly adulterate . . . Martin was referring specifically to North America, but the sentiment seems to generalize.

  14. More about the anachronistic fruits in particular is detailed in Connie Barlow’s book The Ghosts of Evolution, Nonsensical Fruit, Missing Partners, and other Ecological Anachronisms. (New York: Basic Books, 2000).

  3: The Pronghorn Principle and What Our Guts Flee

  1. The taboos of conservative science are not necessarily bad. Science is slow to accept new ideas and initially regards radical new ideas as taboo, but with good reason. For every brilliant idea that seems ridiculous there are a thousand ridiculous ideas that look and are ridiculous. What separates science from nonscience is in part the stringent filters that winnow away the ridiculous and in the process occasionally also toss a revolutionarily good idea or two.

  2. Hunter was writing about mammoths and mastodons, but his sentiment seems more general.

  3. Hansen, D. M.; Kaiser, C. N.; and Müller, C. B. 2008. Seed Dispersal and Establishment of Endangered Plants on Oceanic Islands: The Janzen-Connell Model, and the Use of Ecological Analogues. PLoS ONE E222 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0002111.

  4. Summers, R. W.; Elliot, D. E.; Urban, J. F.; Thompson, R.; and Weinstock, J. V. 2005. Trichuris suis Therapy in Crohn’s Disease. Gut 54: 87–90.

  5. Five of those patients had gone into remission and the sixth improved. Hopeful, but very preliminary results were presented at the American Gastroenterological Association meetings in May 1999. According to a statement made by Weinstock in an article in the New York Times, the patients were begging to get more worms after the trial.

  6. Because of doctor-patient confidentiality, there is no way to know whether some, all, or none of these patients are still doing better.

  7. Saunders, K. A.; Raine, T.; Cooke, A.; and Lawrence, C. E. 2007. Inhibition of Autoimmune Type 1 Diabetes by Gastrointestinal Helminth Infection. Infection and Immunity 75: 397–407.

  4: The Dirty Realities of What to Do When You Are Sick and Missing Your Worms

  1. These symptoms were apparently the result of magnesium depletion, but why the magnesium depletion occurred in the first place is unclear.

  2. Incan skull surgeries were, in the later years in which they were practiced, actually quite successful. But this was only after a few hundred years of trial and error, the error in this case leading to a very bad day.

  5: Several Things the Gut Knows and the Brain Ignores

  1. Such as the fox and coyote and other animals that biologists tend to call “meso-predators” where meso means intermediate. When meso-predators do better in the absence of bigger, badder predators it is referred to as meso-predator release.

  2. Survey carried out in 2000 by the European Federation of Animal Health (FEDESA).

  3. In 1928, Howard Walter Florey and Ernst Borish Chain shared the prize with Fleming. Fleming, who was a brilliant bacteriologist but kept a sloppy lab, had left a stack of petri dishes growing Staphylococcus bacteria in a pile in the corner while he went on vacation with his family. When he came back from a trip, he noticed that some of the dishes had grown over with fungi. The fungi had apparently killed some of the Staphylococcus in the petri dishes into which it had invaded. Fleming began to eagerly study this fungus, which he referred to as “fungus juice” (later to be named penicillin). In doing so, he would learn more about it, including that it was difficult to isolate, as were its active components. Fleming was able to show that penicillin could kill many kinds of bacteria, but he had less success making it useful as a treatment. He needed help from a chemist to isolate the active component in penicillin, but no one would help and so, in essence, he worked on the project for twenty years before abandoning it. It was then that Florey and Chain, unaware that Fleming was even still alive, took up the challenge of isolating penicillin. To this strange story, we owe penicillin and millions of human lives.

  4. The four treatments were “(no antibiotics), streptomycin (0.5 g/250 ml drinking water), streptomycin-bacitracin (0.5 g of each/250 ml drinking water), and vancomycin (0.125 g)-neomycin (0.25 g)-metronidazole (0.25 g)-ampicillin (0.25 g, combined in 250 ml water).”

  5. Some microbiologists now argue that the distinction between “bad” and “good” bacteria is a false one. Whether they are bad or good depends more on where they are than who they are. E. coli in the gut at low densities is all right, but at high densities or inside the body cavity it can be deadly.

  6. Thone, F. 1937. Germ-free Guinea Pigs. Science News Letter 31: 186–188.

  7. This is what Reyniers believed. The truth was more complicated, as it often is. In the late 1800s, two Germans, George Nuttal and H. Thierfelder tried an approach very similar to the one Reyniers was about to undertake. Simultaneous with Reyniers’s work (and also apparently unknown to him), a group in Sweden led by Bengt Gustafsson and his professor, Gusta Glimstedt, was attempting to establish germ-free rats. The history of these other attempts at germ-free life is well chronicled by Philip B. Carter and Henry L. Forster in their chapter Gnotobiotics in the now classic (and fascinating, I promise) book, The Laboratory Rat by M. A. Suckow, S. Weisbroth, and C. L. Franklin, the 2nd edition of which was published in 2007 by CRC Press in Boca Raton, Fla.

  8. From an interview with Philip Trexler on June 11, 2010, when he was ninety-eight years old. Trexler was to become a man behind the scenes at the Lund Institute, where he initially helped Reyniers and then eventually took over much of the work of innovating new technologies. Trexler would be key, in particular, in developing technologies to be used during human surgeries to create miniature germ-free environments on humans, though only for a moment.

  9. http://www.time.com/time/magazine/article/0,9171,883334,00.html.

  10. By 1937, he was to be the sole faculty member in charge of a 5,000-square-foot facility dedicated solely to the study of germ-free animals. It was a building of germ-free life. In it, by 1950 he was in charge of even more space and people as well as an individual chamber large enough to house 1,000 animals including chickens, guinea pigs, and rats, but by then also monkeys. Scientists had to dive through a vat of antibiotics in order to get into the large chambers, as though passing into a brave new world. Germ-Free Animal Colony Begun in Notre Dame Tank. New York Times, June 22, 1950.

  11. Experiments done by Dr. J. R. Blayney in Reyniers’s group would be the first to show that bacteria were responsible for tooth decay.

  12. Gordon, H. A., and L. Pesti. 1971. The Gnotobiotic Animal as a Tool in the Study of Host Microbial Relationships. Bacteriological Reviews 35: 390–429.

  13. Though he would commit some follies because of hubris. It was one of those follies that would get him fired from Lobund, fired for what the chancellor at the time referred to as “financial flim flam.” It was also that hubris that caused Reyniers to continue to favor the production, sales, and advocacy of metal germ-free chambers that cost thousands of dollars even when Philip Trexler had figured out how to produce plastic chambers at a cost of a few hundred dollars. The metal chambers made Reyniers’s fami
ly machine-shop money. The plastic chambers would not.

  14. Rukhmi, V.; Bhat, C.; and Deshmukh, T. 2003. A Study of Vitamin K Status in Children on Prolonged Antibiotic Therapy. Indian Pediatrics 40:36–40.

  15. For a review of this exciting new area of research, see F. Bäckhed. 2009. Addressing the Gut Microbiome and Implications for Obesity. International Dairy Journal 20: 259–261. Yes, this means there is, in fact, a dairy journal.

  16. There are actually, I believe, two times in the history of biology when science threatened to dissolve as a consequence of individuals speaking many languages. In the first case, one I write about in Every Living Thing, individual scientists were naming plants and animals with different names in different countries (and even within the same country). There was no common language for naming life, and for a while it wasn’t clear that one would emerge. The second occasion is, I believe, the situation in which we currently find ourselves, when different fields of science in general, but biology in particular, are so mutually unintelligible that scientists in one field tend to turn to popular (rather than scholarly) accounts of other fields to understand them.

 

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