Human evolution is one of the most interesting, and controversial, topics in paleontology and paleoanthropology. We've found specimens of many early homonids, primarily in Africa. One of the oldest of these was 'Lucy', a partial skeleton of Australopithecus afarensis. There were few, to no, remains of any hominids older than it.
That is, until the discovery of 'Ardi', an Ardipithecus ramidus, in modern Ethiopia. It is about 1 million years older than Australopithecus, and has an interesting mosaic of traits. Some are very "primitive:" an opposable big toe, for instance. Others are "derived," existing in later homonids. Curiously, it has many traits that are not in modern African apes. Thus, chimpanzees and gorillas have evolved significantly in the past 4.4 million years. This means they are also poor examples of what our common ancestor may have looked and acted like. Ardi brings us closer to that elusive creature, but is still not the branching points scientists are looking for. Nevertheless, Ardi is an exciting new addition to the hominid family tree. It brings some new insights, and, as with most new discoveries, a whole bunch of new questions. Only further discoveries will clear up the questions of human evolution.
Discovery Channel will be airing a special on Ardi and the importance of this discovery on October 11. Check their website for more information.
Credit: Science Daily- Before 'Lucy', There was 'Ardi': First Major Analysis of Early Hominid Published in Science.