If you haven’t heard by now, Ida is a 47 million year old fossil which headline writers the world over are calling the missing link between humans and animals.
Strictly speaking, of course, there is no such thing as the missing link. The term was coined in Darwin’s time by naturalists who didn’t yet subscribe to the theory of natural selection, because Darwin couldn’t produce fossils which showed transition from one species to another.
The myth of the missing link persists to this day as a straw man argument, predominantly from creationists in the American evangelical movement, despite that we now have a much better understanding of how fossils form and why they are so rare.
However, since Darwin’s day, not only have we found many thousands of fossils which could be described as transitory, such as Nautiloids to Ammonoids, Invertebrates to Fish and so on, but thanks to the unwrapping of the genome we know that natural selection takes place on a much more gradual scale than it would be possible to show in the fossil record in any case.
Ida is still very important, however, because she is the nearest common ancestor of the ring tailed lemur, which connects apes to humans and humans to the rest of the evolutionary tree of life.