There does not seem to be any evidence of such hybridization in the genetic history of life on earth. The common descent of all living terrestrial organisms, on the other hand, is well-supported by the evidence available to us. All living organisms share the same genetic history.
Writing in The Ancestorâ€™s Tale, Richard Dawkins states, â€œWe can be very sure there really is a single concestor of all surviving life forms on this planet. The evidence is that all that have ever been examined share (exactly in most cases, almost exactly in all the rest) the same genetic code; and the genetic code is too detailed, in arbitrary aspects of its complexity, to have been invented twice.â€ (p.7) (Note, the word “concestor” refers to “common ancestor.” The term was coined by one of Dawkins’ assistants, and he uses it throughout the work.)
It also seems highly improbable that an alien species would have engaged in such a project then abandoned it rather than sticking around to see what happened. I suppose there might have been some sort of drive-by planetary ejaculation, but it seems unlikely.
Finally, you need to support the claim we occupy a purpose-driven universe. I see no evidence to support that idea either. Certainly, human lives may be purpose-driven, but the purpose is supplied by the humans involved, not some external source.
It’s fun to speculate about things like alien hybridization, and there have been some interesting works of science fiction dealing with those themes.
But the evolutionary history of life on earth is well documented now, and we learn more with every passing day. The story of how we came to be human is one that is still emerging, and we have much to learn.
However, there does not appear to be any need for intervention in that story by either aliens or gods.
Posted: May 12th 2009
See all questions answered by George Ricker