My primary objection as a geneticist [to the grand genetic narrative of Evolution] was to the claim that the formation of races, or microevolution, as it is often referred to, is a small scale example of macroevolution - the origin of species. Race formation is, of course, very well documented. All it requires is isolation of a part of a population. After a few generations, due to natural selection and genetic drift, the isolated population will irreversibly lose some genes, and thus, as long as the isolation continues, in some features it will be different from the population it arose from. In fact, we do this ourselves all the time when breeding, substituting natural with artificial selection and creating artificial barriers to generative mixing outside the domesticated conditions.--Maciej Giertych, full text available at Uncommon Descent
The important thing to remember here is that a race is genetically impoverished relative to the whole population. It has fewer alleles (forms of genes). Some of them are arranged into special, interesting, rare combinations. This is particularly achieved by guided recombination of selected forms in breeding work. But these selected forms are less variable (less polymorphic). Thus what is referred to as micro-evolution represents natural or artificial reduction of the gene pool. You will not get Evolution that way. Evolution means construction of new genes. It means increase in the amount of genetic information, and not reduction of it.
Monday, November 20, 2006
The evolution of creation
A geneticist notes some important facts about what has been and can be observed empirically as opposed to stories that are imagined about the past: