Thread: Common ancestor question

Is "Common ancestor" a species or an individual when talking about a common ancestor of two species?
In other words, does the separation from one to two species origin from a group of the earlier species or from a single individual from that species? For ex. common ancestor of humans and Chimpanzees.

In general it would be a species/population, not necessarily all of the members of a species, but a group of them. When you're looking back at the fossil record what you get is for a certain amount of time you find fossils which are human-like and chimp-like, then eventually you start to get fossils that could be ancestors to both humans and chimps. One of these species could be a common ancestor or a cousin of the last common ancestor, you can't be really sure. So, it's very difficult with fossils to point directly at the last common ancestors of two species, but you tend to be able to get a rough time period when the LCA lived.