I’ve just realized I read more than I needed to in Wild Life of Our Bodies. Three days out of state for my interview threw off my schedule, so I apologize. I’ll keep this post here and write a new one for class.
I’ll stick to my usual theme and focus on one element of the reading and leave the rest for discussion in class.
Broadly, I agree with the proposition that a lack of worms in our guts may result in a disequilibrium and subsequently in disease. The interdependence of life on Earth is an indisputable but often overlooked reality because so much of that reality is not visible (e.g., the insides of our stomachs). I’ve been told there are ten times more bacterial cells in and on our bodies than there are eukaryotic cells that make up our bodies (Interestingly, there are also more viruses on Earth than there are cells.). If our bodies did in fact evolve with a multitude of worms and other organisms living and our guts, it is reasonable to assume that our bodies evolved with them and developed an equilibrium in their presence so long as they weren’t life threatening.
So, Dunn’s “math” seems correct. If human gut + worms = stability, then human gut – worms = instability. Unfortunately, he again seems to travel along these tracks of assumptions that don’t hold up, making too many logical leaps in the process. While Dr. Nelson was right that the theme of the chapter on snakes and vision was not “The evolution of human vision” or “How we got our large brains,” I can’t up but begin to recognize a pattern in Dunn’s thinking, where he draws premature connections between dots that are fuzzy. I do give him credit for admitting most of the time when his positions are plausible but not proven.
For instance, he writes on page 43: “…the broader reality is that our immune systems appear to have evolved in a such a way as to function ‘normally’ only when worms are present.” With this statement, Dunn is ignoring the absurd prevalence of disease prior to the invention of sanitation, antiseptics, and antibiotics (while he does admit to their usefulness in subsequent chapters). He ignores that, in developed countries, infectious diseases (I assume) are much less of a problem than in developing countries. Ever since I started taking zinc supplements and drinking green tea several times a day, I can’t remember the last time I had a cold. My immune system, and those of most of the developed world, seem fine–if not quite healthy–so I can’t help but be alarmed by the sentence I quoted. For Crohn’s disease, his argument seems quite sound, but a 1 in 500 prevalence of a single disease is not nearly enough to make such a claim. We also cannot ignore the possibility that these same worms were also frequent carriers of other agents that may have caused more disease than they prevented.
I like the ideas Dunn explores. The bit about the pronghorns was a very interesting digression to make a compelling argument (Though, I will say that I don’t agree it matters that pronghorn waste energy running from everything, so long as they are able to reproduce.) However, he does not seem to have enough of a complete picture of the science he is attempting to explore. Either he is translating complex processes into simple language for the average reader, or he is below the level of “expert” in some of these areas and is connecting dots on a map he does not know enough about.
Despite my complains, Dunn does recognize an important overarching theme in human development in the last century: we began with a “Kill them all now and ask questions later” approach to our problems. We had problems, and in response we produced blunt and excessive solutions that ignore the nuances and complexity of our biology and the world in general.