The ancestors of horses are each known from dozens, hundreds, or in some cases even thousands, of virtually complete specimens. Yet hominin species of the same age are often known only from one or a...

The ancestors of horses are each known from dozens, hundreds, or in some cases even thousands, of virtually complete specimens. Yet hominin species of the same age are often known only from one or a very few partial specimens, such as the crushed partial skull of Sahelanthropus. As a result, we understand equine evolution much better than we do hominid evolution. Speculate as to why this is so: Why are hominin fossils rare? Does the scarcity of hominin fossils invalidate the conclusions of paleontologists? Put another way, is it really possible to learn anything useful from a single bone fragment?