65:4.12

But in our effort to provide for that combination and association of inheritance factors which finally gave rise to the mammalian ancestors of the human race, we were confronted with the necessity of permitting hundreds and thousands of other and comparatively useless combinations and associations of inheritance factors to take place. Many of these seemingly strange by-products of our efforts are certain to meet your gaze as you dig back into the planetary past, and I can well understand how puzzling some of these things must be to the limited human viewpoint.