Genetics of the Evolutionary Process

by Theodosius Dobzhansky

Book Overview

The world's foremost geneticist surveys the major developments in what is emerging as the most important single area of scientific inquiry in the twentieth century: biological theory of evolution.

• Format: Hardcover
• Language: English
• ISBN: 0231028377
• ISBN13: 9780231028370
• Release Date: January 1970
• Publisher: Columbia University Press
• Length: 505 Pages
• Weight: 2.05 lbs.

Customer Reviews

A BROAD-RANGING BOOK FROM A FAMOUS EVOLUTIONARY THEORIST

Theodosius Dobzhansky (1900-1975) was a famous geneticist and evolutionary biologist. This 1970 book (like several of Dobzhansky's later works) covers more than simply evolutionary theory. He begins by noting that "Organic diversity is a response of living matter to the diversity of environments, and of opportunities for different modes of life on our planet." "The gene pool is in constant motion; if a simile is desired, a stormy sea is more appropriate than a beanbag." However, he cautions, "Talking about traits as though they were independent entities is responsible for much confusion in biological, and particular in evolutionary, thought." He observes, "Suppose that one wishes to transform, by selective breeding, the human race into a race of angels. We can be virtually certain that it would be much easier to breed for angelic disposition than for a pair of wings because there is available in human populations a variance in disposition.... There is much less chance of encountering variants on the basis of which the development of wings may be started, and to expect mutations providing such a basis seems rather farfetched. And yet birds and mammals, or bats and primates, have had a common albeit remote, ancestry. There is no possibility of repeating, however, or reversing and repeating the evolutionary process that gave rise to these winged and wingless creatures." Dobzhansky notes that of divergent phenotypes in humans, "a great majority ... represent mild or serious genetic defects or diseases." He also admits that "the problems of the maintenance of genetic variability in natural populations, and of the ways in which natural selection acts, are as yet far from solved. These are basic problems of any causal theory of evolution.... Moreover, it is probable that the state of the knowledge as outlined above will be surpassed in the near future." An original contribution in this volume is the notion of evolution proceeding by "random walk": "evolution by random walk must be regarded as an important, or even prevalent, evolutionary mode," and "The problem of evolution by random walk invites further studies." As with other books of Dobzhansky's (e.g., Heredity, Race and Society), he strongly criticizes then-current theories of racial origins that were used to justify racist theories: "It should be made unequivocally clear that the number of races or subspecies which one chooses to recognize by giving them vernacular or formal Latin names is largely, though not completely, arbitrary." He concludes by saying that "The evolution of every phyletic line yields a novelty that never existed before and is a unique, unrepeatable, and irreversible proceeding..... An evolutionary history is a unique chain of events," and "I feel that a biologist may reasonably speak of evolutionary progress, provided only that he makes clear what kind of progress is meant." This is a significant work by a major modern evolutionary thinker.