Where did we come from? Part IV

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Previously we discussed
Part II : Class Mammalia --> Order Primates
Part III : Family Hominidae

I recommend you go through Part III if you'd like a recap.

Our report card says we've successfully filtered our genes down to the tribe Hominini (which is why we're called hominins) which is then divided into 3 subtribes: subtribe Panina (who we've outsmarted), subtribe Australopithecina (who we've outlived) and subtribe Hominina (that's us).

After this long-winded journey that weened out trait after trait that wouldn't do, we arrived at the genus Homo.


HOMO

A lot of us are aware that the we belong to the species Homo sapiens. What is not common knowledge is that all species belonging to the genus Homo are technically humans. Homo, in Latin, means 'human' and it's obvious that when this genus was named so, we didn't expect to find remains of other extinct human species. The second part of our name, "sapiens", means "intelligent" or "wise" (you might recognize the same root, sapere, in the word sapiosexual or sapient). Let's find out a little bit about the other humans that didn't make it far enough to give us company.

Species that were our direct ancestors

Homo ergaster : 'The handyman', found with tools, in Africa. It is possible that this isn't a distinct species (that the specimens which are currently said to belong to this species, don't), but if it was, it's one of our ancestors.

Homo heidelbergensis: Named so because they were first found near the city of Heidelberg, in Germany. It is believed that the African population of H. heidelbergensis gave rise to the H. sapiens.

Species that weren't our direct ancestors

Homo erectus : or the erect humans. There is confusion regarding H. ergaster and H. erectus. If they really were two different species, then this would be a descendant of H. ergaster. Remains found in China and Indonesia.

Homo neanderthalis : We all recognise this name, which literally means 'humans from the Neander Valley (Germany)'. It refers to the species that descended from the European population of H. heidelbergensis but were not our direct ancestors.

Homo floresienses : Found from Flores, Indonesia for the first time, this species' diminutive form leads to it being nicknamed hobbits. It is believed that this species co-existed with, and might have been driven to extinction by, modern humans. Sounds familiar?

Species we're not sure about

Homo habilis : Lived in Africa, also called 'the handy man' because its fossils have been found accompanied with tools made of stone.

Homo rudolfensis: Named so because it was found near Lake Rudolf in Kenya. We don't know the color of its nose.

Homo antecessor: Or 'the explorers'. Earliest humans in Europe.


WHY IS EVERYTHING SO VAGUE?

It's evident that we have large holes in our knowledge of our ancestors. Why would this be, if we have intelligent and motivated teams of paleoanthropologists actively researching our roots?

Paleontology depends heavily on the following things:
- the preservation of fossils
- their discovery
- their identification, and
- their analysis

As it turns out, each of these steps has its own sets of problems. For instance, consider the tiny odds that a skull or a femur of a dead human will be buried soon enough so that it is not broken, pulverized or eroded. Consider the tiny odds that scientists will look in the very same place where these fossils are lying in wait, especially noting how urbanization covers our planet with concrete and clay. Next, imagine the difficulties of having to first define a new species on the basis of specimens that might be only partially preserved, and then wondering whether a specimen belongs to a previously defined species or not. Last, but of paramount difficulty, is the question of what a particular morphological character means. Do we look at the jaw of a set of fossils and try to understand how they were related, or the teeth? Which evolutionary path did a lineage take? Does descent even unambiguously show up in the hard parts, or were there subtle signatures that were not ossified?

Paleoanthropologists face a variety of problems in deciphering a patchy fossil record that sometimes leaves us with more questions than answers. However, there's no doubt that it is an extremely exciting field of research, where each discovery brings us closer to the knowledge of where we came from.



If you'd like to keep up with more posts on Paleoanthropology:

 

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