I’m taking animal physiology this semester. I’ve reached a stage of life where learning is purely for enjoyment. I’m not working towards a degree. I’m not going to be going to grad school. I don’t need a PhD.
One of my undergraduate degrees is in biology (the other in journalism) and most of my work was with plants or microbiology. I graduated 37 years ago and there have been a couple advances since then. There are a few more women biology professors. They are addressed as Dr. rather than Mrs. In my class, the professor is a woman, there are 7 female students and 17 male students. This is an improvement. When I worked towards my biology degree, I don’t recall an upper division class with more than 5 female students.
Something else has changed. Working towards my degree, I fought against the notion of evolution. I could not and still cannot comprehend a big bang accidently leading to a single cell and then accidently morphing up the phylogeny tree to eventually create a human with not only an opposable thumb, but also the capacity to think, create, and have a sense of right and wrong. Life is far too organized and far too complicated to be nothing more than an accident. This belief caused much consternation between myself and my professors.
I did, and still do, believe in natural selection. With natural selection, you don’t end up with something you didn’t have before; but the population of what you had before is now a bit different. Consider the tomato and tobacco mosaic virus. There is a natural resistance to TMV, but it’s not a complete resistance. In the lab, tomatoes are grown and TMV is introduced. This kills almost all of the plants which had no resistance. Then, the temperature is raised and TMV is introduced again. This time, almost all of the plants with only one resistant gene died and the plants with two resistant genes lived. You still have tomatoes, but more of the tomatoes are resistant to TMV than before “naturally” selecting for the resistant varieties.
Physiology includes change over time. As the environment of a given animal changes – hotter or cooler ambient temperature, more or less participation, change in the abundance of preferred food – those animals in the population that have the genetic ability to adapt will live and reproduce. Those without that genetic ability die off. There’s no accident here – merely cause, effect and natural selection. The complexity and amazing organization of life remains.
And that’s what I learned in my animal physiology class.