The current issue of Science introduces us to our oldest known ancestor: Ardipithecus. Coming only after fifteen years of meticulous research by Tim White and his team, this announcement is a cause for celebration for those of us who treasure hard-earned evidence-based knowledge. At Daily Dish, though, Andrew Sullivan introduces Ardipithecus with a disclaimer: "If by any chance you are a fundamentalist Christian, skip this post. You can't handle the truth." I haven't yet received the issue of Science featuring Ardipithecus, but I am very much on the lookout. In the meantime, Karl Zimmer of The Loom offers a highly readable overview of the newly released findings:

Ardipithecus’s feet were mosaics too. The four little toes were adapted for walking on the ground. Yet the big toe was still opposable, much like our thumbs. This sort of big toe helped Ardipithecus move through the trees much more adeptly than Lucy. But Ardipithecus could not climb through trees as well as, say, chimpanzees. Chimpanzees have lots of adaptations in their arms and shoulders to let them hang from branches and climb vertically up trees with incredible speed. Ardipithecus had hands were not stiffened enough to let them move like chimpanzees. Ardipithecus probably moved carefully through the trees, using its hands and feet all at once to grip branches.

It's not every day that we push back one-million years further regarding our understanding of our ancestry. This is an extraordinary discovery by Tim White (who was also part of the time who uncovered "Lucy" (Australopithecus afarensis) in the early 1970's. Today, I will revel in the thought that, more than four million years ago, our tree-crawling ancestors were living valiantly and carefully enough to pass on their genes so that we modern house-dwelling (and car-dwelling) humans could scientifically contemplate their way of life. It is all so very bracing . . .