G.G. Simpson, This View of Life (Harcourt,
Brace & World, New York, 1964), pp. 284-285.
Even now we know enough about the central process of past evolution,
natural selection, to make a good start at improving the breeds of Homo sapiens,
as we have in fact used this knowledge to improve breeds of other species.
There is, furthermore, reason to think that we are on the verge of
further biological discoveries that could make selection far more effective or could even
supplant it with other, faster and surer evolutionary processes. It is probable that the
incidence of mutations can be controlled within broad limits: instances are known in which
the rate of mutation is itself a genetic factor subject to selection. Control over the
direction of mutation, possible now only in a few quite special cases, is another eventual
probability. Growing knowledge of the actual chemical nature and structure of genes holds
the possibility that genes or in the end even whole genetic systems can be made to order.
The guidance of evolution could then become a simple matter of following specifications.
...it is unquestionably possible for man to guide his own evolution
(within limits) along desirable lines.
G.G. Simpson, Biology and Man (Harcourt,
Brace & World, New York, 1969), p. 129.
...The problems of tailoring a gene and inserting it in human sperm or
egg, making it hereditary, are so many and so little understood at present that reasonable
prediction would place that in a future very remote indeed. Moreover, the human (or any
other viable and natural) gene system is so intricately balanced that insertion of a
foreign element, however well specified in itself, would probably have disastrous effects.