Anthropology

Understanding our early (very, very early) ancestors is a key component to understanding human evolution. The Australopithecus genus has many different species within it. There are Australopithecus: aetipicus, garhi, africanus, robustus, and anamensis. All of these species played a big part in the evolution of humans. But Australopithecus robustus and anamensis could possible have played a bigger role than any of the other species. These are the two species that will be the focus of this paper. Australopithecus robustus and anamensis are extremely different from each other and the other four species, even though they are of the same genus. But yet even with their variations, they are still to a great extent alike.

Australopithecus anamensis is the “ oldest” of the Australopithecus genus dating back to about four million years ago. The first fossils of this species were found in 1965 in Lake Turkana on the borders of Kenya and Ethiopia in between two layers of volcanic ash. But it wasn’t until the 1990’s and after they found a molar that the researchers realized that they had come across Australopithecus anamensis. They were classified in the species of Australopithecus afircanus, until they decided to move them to their own species. Every Australopithecus anamensis fossil that was found was found within the general premises of Lake Turkana, with fragments of fossils showing up between Lake Turkana and Allia Bay, these two places are the two most important places for finding fossils of early hominids. Almost the entire Australopithecus genus has had some type of fossil found in this area. But for the Australopithecus anamensis, this area produced an almost intact humerus and tibia, which helped scientist like Meave Leaky; further their searches for Australopithecus species within the Lake Trukana area. Judging by how the body structure of the Australopithecus anamensis were shaped scientist are able to know that around this area, the terrain varied considerably between open, brushy, or filled with trees. The anatomy of the Australopithecus anamensis is very interesting because one aspect of it points to the ape likeness of it. For one thing the Australopithecus anamensis is thought to have been a tree climber, which was common with early hominids. But there are also another aspects that point towards it being a hominid. The jaw of the Australopithecus anamensis is what points towards it being more ape-like. While us humans have a jaw that is rounded and pretty much symmetrical, the Australopithecus anamensis has a mouth that is very parallel and the teeth are not symmetrical. Also the roof of the mouth is not as deep as that of a later Australopithecus species, or us humans. Even as convincing as that sounds, Australopithecus anamensis is more human than ape. The skeletal structure of the Australopithecus anamensis is what makes it more human than ape. From the tibia that the scientist found, they saw that there was a formidable amount of stress on that tibia because part f that bone was thicker indicating stress from walking in a bipedal movement (which is one of main characteristics of hominids). Also the cartilage that “connects” the femur to the knee was deeply curved, which is distinctive in hominids. Australopithecus anamensis is particularly important to understanding human evolution because it is the first (oldest) species of the genus.

The Australopithecus robustus is the “youngest” of the Australopithecus genus, discovered in 1938 by Robert Bloom in South Africa. When he came across the skull, he thought that he had come across an Australopithecus africanus skull, but it was larger, more gorilla like (flatter facial features), and the brain size was about fifteen percent bigger than that of an Australopithecus africanus brain. “The increase in body size over africanus is minimal, which means that there is significantly increased encephalization, rather