Ape-Human Split Moved Back By Millions Of Years

E++99 writes in to let us know about a development in paleo-anthropology. It seems that up until now, scientific consensus has placed the divergence of man from the ape line five to six million years ago (based on "genetic distances"). But newly discovered fossils in Ethiopia place the divergence at least twice as far back, and perhaps as long ago as 20 million years. They also largely put to rest any doubts that man and modern apes both emerged from Africa. From the article: "The trail in the hunt for physical evidence of our human ancestors goes cold some six or seven million years ago... Beyond that... fossils of early humans from the Miocene period, 23 to five million years ago, disappear. Fossils of early apes especially during the critical period of 14 to eight million years ago were virtually non-existent — until now... [T]he new fossils, dubbed 'Chororapithecus abyssinicus' by the team of Japanese and Ethiopian paleo-anthropologists who found them, place the early ancestors of the modern day gorilla 10 to 10.5 million years in the past, suggesting that the human-ape split occurred before that."

Comments

Re:Misleading to talk about a "human-ape split"

[j01123]

Apes are monophyletic, because apes include humans. You are correct though, that the non-human apes are paraphyletic, because the closest living relative of the chimps are humans.

My impression of the Nature article (subscription required) is that the authors are claiming that their paleontologic find pushes the gorilla split (from the human-chimp lineage) back to ~12 million years. Based on this, they essentially recalibrate the molecular clock as it relates to several of the ape divergences. This information is in section 5 of the paper's online supplementary materials (subscription not required), not the body of the article. Keep in mind that supplementary materials generally aren't peer-reviewed as rigorously as the rest of the article.

Easy... it's pretty butchered and you're wrong.

[Tatarize]

Dinosaurs died out 65 million years ago at the KT boundary.

Prior to that time the mammal line had already split much more than we previously gave it credit for, a lot of the main groups were developed. This article is a fairly worthless crock. Basically some teeth were found that looked vaguely gorilla like and dated back 10 million years. So we know that there was some ape-like creature with a gorilla-like diet 10 million years ago. However, saying that this is the Ape-Human split is as stupid as saying it's the Human-Mammal split. Humans are apes. We are clearly within the same grouping of gorillas, orangutans, and chimps. There's no real grouping of animals which includes those yet excludes humans. This find perhaps sets back the date of chimp-gorilla split but not "human-ape". That's just stupid. Chimp-human is a split which dates back about 4-6 million years. Gorilla-chimp goes back 8 million years, though perhaps 10 if this isn't just some offshoot.

Finally, 10 million years is about 2/17th of 85 million years. Basically your math is off, and you're using old information, and to top it off this article is totally stupid. It's 10 million year old gorilla-like teeth. It actually has almost nothing to do with human evolution, though if you studied gorilla evolution you might care. Though, it's even weak evidence that it's actually a gorilla just that it had a diet like that of a gorilla.