Chapter 5.                     Part B                                                                                       

Doberman Pinscher

     

In a more scientific example, I will also mention our Doberman Pinscher-cross pup. Rex was basically a good dog, but he was a mutt, a Doberman cross that we obtained because one of my aunts could not keep him. People often remarked that he looked like a Doberman, but his tail was not bobbed. This got me curious. When I found out that Dobermans had almost all had their tails bobbed for many generations, I wondered why the tails, after so many generations of bobbing, had not simply become shortened at birth. I asked a Biology teacher at my high school, but his answer only confused me. Actually, I don’t think he understood the crucial features of Darwinian evolution theory himself.

                

                                                 Jean-Batiste Lamarck 

Once I got to university, several of the courses I took were in Biology. Gradually, at first, and then in a breakthrough of understanding, I came to realize that I had been thinking in terms of the model of evolution called “Lamarckism”. I did not, at first, want to let go of this cherished opinion of mine. I had thought of myself as progressive, modern, scientific; I did not believe in creationism. I had thought that I knew how evolution worked and that I was using an accurate understanding of it in all of my thinking. It was only after I had read more and seen by experience that bobbing dogs’ tails did not make their pups’ tails get any shorter, that I, gradually at first, and then in a mental leap, came to a full understanding of Darwinian evolution. 

Evolution for all species proceeds by the combined processes of genetic variation and natural selection. It doesn’t matter how often the anatomies of already existing members of a species are altered; if their gene pool doesn’t change, the next generation will, at birth, basically look pretty much like their parents did at birth. Chopping off a dog’s tail doesn’t change the genes that he or she carries in the sex cells that will govern how long her/his pups’ tails will be.

In nature, of course, some individuals no longer being well camouflaged in their changing environment, and so being easy prey, or their being unable to adapt to a changing climate, etc. causes some individual members of the species to die young or to reproduce less efficiently, while their stronger, smarter, or better camouflaged cousins flourish. 

Then, over generations, the actual gene pool of the local community of that species does change. It contains more genes for short, climbing legs or long running legs or short tails or long tails or whatever the local environment is now paying a premium for. Gradually, the anatomy of the average species member changes. If short-tailed members have been surviving better for the last sixty generations, and long-tailed members have been dying young, before they could reproduce, this changes the gene pool. Eventually, as a consequence, there will be many more individuals with the shorter tail which has now become a normal trait of the species.  

Pondering Rex’s case helped me to absorb Darwinism. My understanding grew and then, one day, through a mental leap, I suddenly "got" the newer, better model. A model that I hadn’t understood suddenly became clear, and it gave a deeper coherence to all of my ideas and observations about living things. For me, Lamarckism then became an interesting footnote in the history of Science, sometimes still useful because it showed me one way in which my thinking, and that of others, could go wrong.