Saturday, February 12, 2005

My Cousin Vinny, The Variation of Animals and Plants Under Domestication, and "Bitch-Slapping" Behe

I just finished watching "My Cousin Vinny" wherein we learn such anthropological tidbits as what "utes" are (that's an anthropology joke for those of you unacquainted with native american tribes).
But what I really want to blog about is Charles Darwin. Today is his birthday. In terms of anthropology, his most important book (next to the Origin of Species) is "The Descent of Man". In it Darwin analyze the variabilty and distribution of the primates and concludes that humans evolved in Africa. A prediction that turned out to be correct.
"The Variation of Animals and Plants Under Domestication" is less well know than either of the two books mentioned above, but is in someways more interesting. I have the two volume edition put out by Johns Hopkins University Press. In the foreword the editor (Harriet Ritvo) says the following:
"As a graduate student from the People's Republic of China told me several years ago, after having participated in a seminar that read excerpts from Variation and the Expression of Emotions, if the leaders of his government knew that Darwin had written such books, he would not be officially admired."

Leaving aside the similarities of the above qoute to some of the stories the creationist tell about Darwin, the forward is similarly derogatory in nature. I think this symptomatic of the way the work is viewed. I, on the other hand, think the book is under appreciated. Bearing in mind that I have justed started on chapter 20, here is a synopsis of the book. The first eleven chapters discuss variability in animals and plants that have been domesticated by humans. Throughout we see Darwin trying to apply the ideas he ennuciated in "the Origin of Species" -namely selection and desent with modification- to the problem of variability in domesticated animals. For example, he tries to determine the the ancestors of most of the species he discusses. For some species, such as dogs, he identifies several ancestors (in modern parlance, they would be considered polyphyletic groupings). For others, such as the chicken and pidgeon he identifies a single ancestor (Gallus bankiva for the former, Columba livia for the later). Darwin then uses selection to explain how, say, Gallus bankiva could have evolved into modern varieties of chickens. Along the way, he draws on osteological traits, coloration, behavior and the results of crossbreeding. Two more examples will suffice to show his approach to explaining variation in domesticated animals. First, he discusses dogs and cats in the same chapter. For dogs he points out that selection for a wide variety of traits led to a proliferation of different "types" of dogs. Cats, on the other hand, didn't appear to exhibit the same variation. Mummified cats from Egypt looked much like their Victorian counterparts. What could explain this difference? He points out that for dogs, with breeders emphasizing pedigree, breeding was highly controlled. Whereas for cats breeding was pretty much at random, due to their behavior - at that of their owners. Using modern terminology, dogs were split into a large number of local populations with little opportunity for gene flow between the populations. Cats, on the other hand pretty much roam freely and have a larger effective breeding population - hence there was a lot of gene flow. Second, one of the more interesting aspects of these chapters is the way he uses skeletal material. For example, when discussing rabbits he collected measuremnts on several different species of rabbits and then scaled those measurements to those of wild rabbits. By that I mean that the wild rabbit is used as the standard of comparison and measurements are expressed relative to that standard. In some cases the discussion approaches modern conceptions of allometry.
The next nine chapters are devoted to inheritance (although we don't get to pangenesis until several chapters before the end), hybridism, crossbreeding,and inbreeding. These, to me, are the most fascinating chapters. In them we see Darwin struggling to make sense of a wide variety of data, and outmoded and flatly wrong concepts (reversion, atavism, effects of previous sire, etc.). Two issues were causing Darwin problems. First, the sheer mass of data, often conflicting, which obscured patterns of variation. Second, it seems to me that there was not a adequate "language" for discussing variability and Darwin was clearly struggling. I think what appeals to me the most about the book is that it is an intellectually honest survey on the nature of variation and I have the impression that Darwin was never satisfied with his conclusion.

On that note, Evolutionblog was the first to report on Bruce Albert's response to Behe's Op-Ed piece in the New York Times. But first, a little history. In "Darwins Black Box" Behe takes several shots at Alberts. On page 115 Behe dismises Alberts' textbook (Molecular Biology of the Cell) as irrelevant to molecular evolution (mainly in the context of the evolution of vesicular transport). Then on page 152 he takes another shot regarding the discussion of metabolic pathways in Alberts' book. I don't know if Alberts' ever responded to Behe on that issue, but clearly Alberts' was angry at the misleading and intellectually dishonest was Behe quoted him in his Times Op=Ed. Pardon my terminolgy but Alberts' applies a gentle "Bitch-slapping" to Behe.

In one scence, early, in "My Cousin Vinny" Ralph Macchio's character is about to fire Vinny. Vinny pleads for one chance to question a witness. The prosecution's case, he says, is like a brick wall. First a foundation is laid and then new layers are added, each supporting the next. The dimensions fit, he says running his fingers along the length and width of a playing card. However, with a change of perspective (and here he turns the card flat) the bricks are really thin. This is a good description of ID. The dimensions of the the bricks fit and the wall they build seems solid, but if you change the perspective the bricks are revealed as to thin and the whole thing comes crashing down like a house of cards. This is why I could never accept ID. There is too much intellectual dishonesty. Rather than twisting peoples words and criticizing evolution, the promoters of ID should focus on developing a research program and conducting experiments. Darwin did!