Carl Zimmer has a great post at The Loom on the historic announcement this week of the discovery of Ardipithecus: We Meet At Last.

At first, Ardipithecus ramidus was yet another scrappy pre-Lucy fossil. The first report offered details about part of a 4.4 million-year-old jaw bone–a remarkable jaw bone, but just a jaw bone nonetheless. Soon after, White’s team found more fossil bones, from the hominid’s hand, skull, pelvis, feet, and on and on–110 pieces all told. But finding these pieces was just the start of the team’s labors. They picked away at the bits of rocks surrounding the fragile bits of fossils. They used a computer to manipulate CT-scans of the fossils to figure out how crushed fragments had originally fit together as a skull or a pelvis.

All this happened in strict secrecy. Some of us science writers knew a little about what the scientists were up to, but we could only guess when they’d finally finish working on the fossil. Sometimes when I’d speak to White, I’d inquire, and he’d politely say he wasn’t done yet.

Looking at the papers out today in Science, you can see that they’ve been very busy. I won’t even try to offer an all-encompassing account of their new results. In many cases, it wouldn’t actually be worth the effort, because these papers are just the first salvo in what will be a fascinating debate about how our ancestors evolved. I was speaking to University of Wisconsin paleoanthropologist John Hawks yesterday on another subject, and he was giddy about the papers’ imminent publication. “Tomorrow’s Christmas!” he said. (His young son overheard him on the phone and got very excited and confused. I had to give Hawks a few minutes to explain the nature of metaphor. Not sure how well that went over.)

UPDATE at 10/4/09 10:01:08 am:

The young earth creationists at Answers in Genesis, of course, accuse the scientists of being “attention seekers” and dismiss the Ardipithecus fossil out of hand.

Without having a live “Ardi” to observe, scientists will only ever be able to come to probabilistic conclusions about its characteristics. As far as we’re concerned, the evolutionary “threat” to creationists from Ardi is no more than that posed by Ida: viz., none.