Still Changing After All These Years

Issue section: 

There is one point that I would like to disagree with in John Parrington's otherwise excellent article on human cloning (January SR).

Parrington argues that 'humans long ago broke free of evolution'. However, this is not the case. Nor do I think that it is quite what Parrington meant to say.

Humans, like all other organisms, are still subject to biological evolution. Evolution by natural selection only requires that there be mutation to generate differences between organisms, that these differences result in differential reproduction, and that these differences are inheritable. However, there is a major evolutionary difference between humans and other organisms, which is that the transmission of culture across generations appears to play a very large role in making us what we are.

Thus I think what Parrington meant to say and should have said is that while humans are still undergoing biological evolution, this process seems to be of much smaller significance than the cultural evolution that we are also undergoing.

Terry Sullivan