6.1: Introduction to Paleoanthropology

Anthropology asks the broad question: “Who are we?” Paleoanthropology asks a more specific question: “How did we get to be what we are?"

In this part of the class we go back in time to follow the branch of the tree of life that leads to us. In the previous sections, we compared and contrasted ourselves to other vertebrates, then to other mammals, then to primates, and mostly to hominoids (apes). In paleoanthropology we start from the split that separates apes from humans and continue on that branch, and all its side branches, until we get to us.

Paleoanthropology deals with hominids (bipedal hominoids). In previous sections, we compared ourselves to living creatures that you can see running around in their natural habitat, but in the paleoanthropology section, most of our knowledge is based on data gathered through archaeology, and we focus on hominid fossils, and how to interpret them.

The next few sections are going to bombard you with specific dates, exotic places, hard to pronounce names, and plenty of Latin. Please try not to miss the forest for the trees. We need to sweat the details. The details are what paleoanthropologists use to support their very tenuous hypotheses. But make sure that when you hear a specific factoid, that you put it in context with a larger framework. So if you hear "Toros-Menalla" you should think "that´s kinda northwest of where most of those other hominid fossils were found." If you hear a species called Homo ergasteryou think "well it's later than the australopithecines because it's of the genus Homo, but it's not quite us because the species name is different than sapiens." If you see a date for Lucy is 3.7-3.5mya you think: "Well she didn't use stone tools because those only appear around two and a half million years ago." If you read that Sahelanthropus tchadensis had a cranial capacity of 320-380 cc, you think "before australopithecines hominids had about the same size brain as chimps do now"

We have found hundreds of thousands of hominid fossils which represent tens of thousands of individuals. When someone claims that there is no "missing link" between apes and humans they are ignoring that huge body of evidence gathered by thousands of scientists. The real debates are about how to include those ten thousand individuals in our family tree, because these thousands of fossils are just a tiny fraction of the billions of hominid ancestors that have lived rich and important lives, but left no physical traces. A genealogical analogy is that you may know from your last name that you belong to certain clan, but you might not be able trace all your relatives back to that apical ancestor; in paleoanthropology there are many gaps.

Important factors for fossils are: dates, where found, morphology (shape), and associated tools.

hominid or hominins?

The confusion over taxonomic terminology gets worse. Recently, many scientists have redefined the term "hominid" to include great apes along with humans. This better reflects our genetic similarity to great apes. To distinguish humans and their bipedal ancestors from great apes they now call us "hominins". I don't really care which terms you use as long as you are consistent. It's always a good idea to define your terms anyway.

You don't want to get lost in the details, and always bring it back to the context of time, place, and relation to the major trends.