Sunday, May 25, 2008

Blog 3: The Genetic Stalemate

In Mad Comics there was a feature called "Spy vs. Spy" in which two cloaked crows, one white and one black, constantly tried to outwit each other. The message I got is that the attempt to outdo another by sneaky means is never completely successful and we end up in a stalemate. I often think of that when we use antibiotics against bacteria, herbicides against weeds, and pesticides against insects. If the agents are not used properly (and many humans are imperfect in their understanding, motivation, or behavior when using such agents) the pests come back resistant to these agents. Thus we have to seek new antibiotics, new herbicides, and new pesticides. In turn these will encounter more resistant mutant strains and again bring back the pests that imperil our health, foods, or lawns. I would much prefer a limited usage of these agents because some of them could be carcinogens or damage human health in other ways. We don’t always test for the unforeseen. Routine use of antibiotics to increase the weight of livestock is not a good idea because of the likelihood of generating resistant strains. Individual use of antibiotics for those individuals who are sick is a good idea because it can save a life. Use of antibiotics to prevent a bacterial infection a person doesn’t have seems less desirable (unless a person has a compromised immune system). Perhaps the medicine and public health of the future will vastly increase the number of microbes for which immunization for life is possible and thus reduce the need for those antibiotics. Developing genetic strains resistant to rotting, worms, insects, and the like might also be a better way of dealing with pests than chemical herbicides and pesticides.

Blog 2: You Look Just Like...

In genealogy we can determine who are grandparents and earlier ancestors were even if they died before we were born and we know little or nothing about them. We do, however, share a measure of their genes and that can be determined by today’s technology. I once heard a grandnephew of Herbert Hoover speak at Stony Brook’s medical school and he looked remarkably like our former president. I also once knew a lady my wife and I visited who had an oil painting of one of her direct ancestors that was painted in Germany in the eighteenth century. Once again there was a remarkable similarity in appearance. But I have also gone to weddings where biological siblings are so different they would be taken for strangers. As a geneticist this makes sense because some genes are passed on and others get shuffled and are not passed on to a descendant. We actually have few experimental or scientific studies of the passing on of facial features – like shape of ears, nose, lips, and other characteristics that are often familial. Part of that paucity comes from an unfortunate use of human pedigrees in the 1920s and 1930s when it was used to justify a spurious belief in the heredity of social failures. After World War II ended and eugenics effectively died, so too did attempts to publish essentially normal human traits. Would a new attention to such normal features risk a return to “social traits” associated with failure and thus resurrect the biases of the old eugenics?

Blog 1: Lunch with C.N. Yang

I once had lunch with C. N. Yang, the Nobel physicist at Stony Brook University. He told me that the major difference between physics and biology was reflected by what each department taught. In the physics department, he told me, any physics professor can teach any course in physics, but in a biology department a geneticist can’t teach ecology, a botanist can’t teach zoology, an endocrinologist can’t teach entomology. I often thought about his remark. It implies that the world of physics is much more connected than the world of biology. In physics almost all laws can be determined from the behavior of atoms, molecules, larger objects on earth, and astronomical objects. This is why a “theory of everything” is at least a plausible theory to pursue for a physicist. But biology is filled with diversity because of the evolution of life and its millions of species and specialized niches for life to live and the interplay of living things in communities and the interplay of molecules in cellular systems. The closest thing to holding all of biology together is evolution by natural selection, but unlike physical laws there are no biological laws that distinguish an animal from a plant or a bacterium unless one gets down to the molecular level where genes and metabolism seem to have universal attributes that cut across all forms of life. For those who seek the mystical, living stuff is irreducible. For reductionists or materialists (in the sense of scientists who refuse to invoke supernatural processes) it is a matter of complexity.