Previously, I wrote about how Richard Dawkins claimed he was an African Ape. Fortuitously, I ran across an article in io9 by Annalee Newitz, The last time we redefined what it means to be human. Newitz clarifies the current cladogram, a diagram that shows relationships among organisms, for humans and their closest primate neighbors (from an evolutionary standpoint).
Humans today are the species sapiens, the genus Homo, the subfamily Homininae, the family Hominidae, the order Primates, the class Mammalia, and the kingdom Animalia. There are other classifications, like tribe and subtribe, sub family, and other fine tuning, which has made the taxonomic classification of organisms complex, especially because of the use of Latin names. Moreover, there are a lot of similar sounding taxonomic groups for humans and great ape relatives. But let’s try to make it as clear as possible..
Currently, the taxonomic classification of primates is a bit confusing, because the hierarchy is subdivided much more than other organisms, possibly because of our interest in our own evolution. So here we go:
Family Hominidae–this is the classification that includes all of the great apes (the “African ape” mentioned by Dawkins, though not all of them are in Africa). The great apes include gorillas, chimpanzees, orangutans, bonobos and humans and all of their extinct ancestors. All members of this family are called hominids, which split from other apes, specifically gibbons, about 15-20 million years ago.
Subtribe Hominina–About 5-8 million years ago, chimpanzees and bonobos (subtribe Panina) diverged from the bipedal apes. All the members of this subtribe, including extinct genera, Ardipithecus (about 5.5-4.4 million years ago), Australopithecus (about 4–1.8 million years ago), and Kenyanthropus (3–2.7 million years ago), Paranthropus (3–1.2 million years ago), along with Homo (the only living genus of the subtribe), are called “hominims.” Homo sapiens are modern humans, which includes those of you reading this article.
Taxonomy is rather complicated, and it makes biologists and anthropologists force organisms into particular groups. Remember that evolution is gradual (unless you’re a proponent of punctuate equilibrium, which states that species are static until some environmental event causes rapid change), so there’s not a single fossil that has a little sign that says “beginning of hominid line.” Using extant species as a starting point (since it’s mostly clear what are or are not members of the same species), you work backwards until some point in time when you can define a split. But the split could have taken thousands or millions of years, and gene flow could have occurred between the groups that would eventual evolve into new species.
If you’re looking for evidence, the peer-reviewed journals are full of separate pieces of evidence. Remember, those who think that human evolution is some sort of lie, think that there’s one article written that has the experiment which “proves” human evolution. There isn’t, though there are a lot of review articles that sum up the current thinking and evidence. Studying evolution is based on thousands, hundreds of thousands of individual papers based on individual observations and experiments.
I find the field of human evolution utterly fascinating. I just wish someone could have renamed all of these groups, so that it was easier to remember. I wrote this post just so I have easy reference for myself in the future!
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