Monday, June 06, 2011

Cogent Words About Race and Genetics

The following quotation is taken from page 179 of ‘Genetics and Origin of Species’ by the eminent Ukrainian geneticist Theodosius Dobzhansky.

Read these words of wisdom and THINK!

“Race and species usually differ from each other in many genes and chromosomal alterations. Interbreeding of race and species results in a breakdown of these systems.... Some of these combinations are the harmonious genotypic systems adapted to the different ecological niches in the environment.

But the Interbreeding could be just as efficient in breaking down the harmonious gene combinations as it was in forming them. Unlimited interbreeding of distinct species would result in submergence of the existing genetic systems in a mass of recombinations. Among the recombinations some may be as harmonious, or in fact better, than the existing gene patterns, and thus by hybridization the species may “discover” new evolutionary possibilities.

But the chance of discovery is pitted against the fact that a majority, and probably a vast majority, of the new genic patterns are discordant, unfit for any available environment, and represent a total loss to the species.

If life is to endure, the gene combinations whose adaptive value has been vouchsafed by natural selection must be protected from disintegration. Without isolation the ravages of natural selection would be too great. But too early and too rigid isolation of the favourable gene combinations formed in the process of race differentiation would mean too much specialization of the organism to environmental conditions that may be only temporary.

The end result may be extinction. Favourable conditions for progressive evolution are created when a certain balance is struck: isolation is necessary, but it must not come too soon.”

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