Tuesday, May 19, 2009

Darwinius masillae, "Ida," possible missing link

Scientists looking at a 47,000,000 year-old fossil think they have found the evolutionary missing link from primates to the rest of the mammal family tree.

The researchers believe it comes from the time when the primate lineage, that diversified into monkeys, apes and ultimately humans, split from a separate group that went on to become lemurs and other less well known species.

Crucially though, Ida is not on the lemur line because she lacks two key characteristics shared by lemurs – a grooming claw on her second toe and a fused set of teeth called a tooth comb. Also, a bone in her ankle called the talus is shaped like members of our branch of the primates. So the researchers believe she may be on our evolutionary line dating from just after the split with the lemurs.

It's amazing what we've learned from evolutionary biology. Given time we may find the entire chain of evolution.