Week 4: How & When Did Chimps & Humans Diverge?

By combining both genetic DNA analysis and data from the fossil record, the article "When Humans, Chimps Were Kissn' Cousins" postulates that the process of human-chimp speciation probably occurred over time, included several inter-bred variations of chimps and humans along the way. Further they conclude that, of these inter-bred human-chimp variations some may have given rise to a sterile offspring while others may have produced fertile offspring for awhile, eventually tapering off to a dead-end for that particular in-bred species. And all of this predates when the final "interbred hybrid groups ultimately began the human lineage".

It makes sense to me that inter-breeding would naturally occur within the context of species development until the final chimp and human species permanently separated, especially since our DNA is 99.4% the same! However, I think that while it is plausible, this theory is still just that: conjecture. We don't really know when or how the human and chimp lines split, and scientists are just making their best guess with the data they have to date. As more information becomes available through cross-pollination between different scientific approaches (anthropology and genetics) and new technologies continue develop, undoubtedly, so, too will our theories of chimp and human evolution.