Loud Thoughts

Becoming Human http://www.becominghuman.org/ http://www.pbs.org/wgbh/nova/beta/evolution/

PBS recently aired this 3-part series of human evolution. The style and structure are like other PBS documentary/educational programs: a narrator with impeccable voice, interviews with impressive experts, and revelations of break-through knowledge. This subject, human evolution, is of interest, so I watched, yes, all three episodes.

We knew that apes became bipeds (primates that walk with two hind legs), then became human. My surprise was that there were many kinds of bipeds that had the advantage of walking more efficiently and seeing farther away. Bipeds, therefore, can hunt in the prairie; unlike their 4-legged cousins that can only gather in the forests. If there were many bipeds, how come there is only one human being now?

Then Africa went through a period of drastic weather changes: drought, flood, and back to drought, repeated many times over several thousand years. Those weather cycles eliminated those bipeds that cannot adopt and only Homo Erectus survived. They have larger brains and adapt better. Homo Erectus migrated from Africa to Europe and pretty much the whole world. They had less hair for more efficient heat disipation over the long distance. They could chase fury animals until the prey became too hot to move. After the kill, their two-legged efficiency enabled them to carry the carcasses back home. The hairlessness and walking capacity were unique advantage for day time huntng. When the sun sets, they built fire to fend off predators. That created communication and social skills. But we are not Homo Erectus, we are Homo Sapiens. Home Erectus went extinct too.

When Africa became desert, Homo Erectus couldn’t survive. Only less than few hundreds went to the coast side and learned to fish. They became smaller (more energy efficient) and even smarter. Several thousand years later, they became Homo Sapiens. In the mean time, those Homo Eractus dominated the rest of the world: Europe, Asia, etc.

Gradually, Homo Sapiens wandered off Africa in search for better food sources. Somehow, when they encountered Homo Erectus, their genetic cousin vanished. They consumed the same foods and therefore are natural rivalries. Homo Sapiens became the dominant resident of this planet some 200,000 years ago.

The most interesting fact is that others have dominated the world for far, far longer time: bipeds and Homo Erectus all survived over 500,000 years. History predicts that Homo Sapiens’ domination will be of limited time. One day, Homo Sapiens will exist only in fossil form.

I will, of course, be long dead. I wonder what would they think when they found the fossil that was me.