In his book Feminism and Freedom
One usually thinks of creationism as a doctrine for religious fundamentalists, but from a methodological point of view, belief in the special creation of the human species is entailed by any refusal to apply evolutionary theory to man. It is irrelevant whether this refusal is sustained by a literalistic reading of scripture or committment to a secular ideology. Indeed, a case can be made that religious critics of Darwin display a stronger sense of the unity of nature than do scientific critics of innateness in man. This is most especially true of scientists like Richard Lewontin and Steven Jay Gould, who take a wholly naturalistic stance toward all living creatures apart from man (and are prepared to use the theory of evolution polemically in ideological debate), yet reject all but the most trivial comparisons of other living creatures to man. (p. 66-67)
In ‘Who is Against Evolution?’, the economist David Friedman also discusses the phenomenon that most people who are against teaching creationism tend to avoid and discourage discussing the human implications of evolution:
People who say they are against teaching the theory of evolution are very likely to be Christian fundamentalists. But people who are against taking seriously the implications of evolution, strongly enough to want to attack those who disagree, including those who teach those implications, are quite likely to be on the left.
To them evolution is good for explaining animal behavior, but using the same tools to explain human behavior, let alone letting it influence public policy, is considered repulsive. It may not be a coincidence that the taboo on discussing human behavior in an evolutionary context parallels the growth of government. A strict “environmentalist” position is more compatible with large scale tinkering and calls for “change” than a view of human nature that accepts limits to the malleability of man.
In fact, all three major political ideologies mostly ignore man as a biological organism. Most conservatives object to evolutionary arguments due to religious convictions or out of fear of being labeled “reductionist.” Progressives generally abhor (and often suppress) biological arguments in political philosophy and public policy altogether. And libertarian-leaning economists feel more comfortable with discussing man as an undifferentiated rational agent despite the clear fact that biology (and associated disciplines like genetics and neuroscience) stands on much firmer scientific ground than many other sciences that inform contemporary public policy. One wonders whether this phenomenon should be attributed to a general aversion of ideologues to biology or whether this is just a transient, irrational, response to the abuse of biological arguments by totalitarian regimes during the first half of the 20th century.