Monday, March 8, 2010

Apes & Human Evolution

Humans and apes share a common ancestor. We are both in the order Primates, superfamily Hominoidea, family Hominidae.
What traits do we humans have that allow us to be classified with Primates? What traits set us apart?

Brain size, teeth, and locomotion (bipedalism) have been used to differentiate species of hominin fossils that have been found. On page 199, Coyne tells us that "bipedal walking was one of the first evolutionary innovations to distinguish us from other apes", and on page 202 that "our upright posture evolved long before our big brain".

Theorize about the order in which our bipedalism, big brains, and teeth evolved. Include why each trait would have been and important advantage and why it came before and after other traits. Include other hominin species and their advantages (for example, we know that H. erectus could use tools and control fire, and had a brain size "nearly equal to that of modern humans" (Coyne 205)).

Also consider the further evolution of humans. Are we done evolving? Are we just too good at fighting disease and other things that would wipe out those without selective advantages? Or are we part of a continuous arc of evolution that will keep producing humans better suited for life on Earth?


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  2. To begin, what classifies us with the primate family is for one, we are mammals, and we have hands, hand-like feet, and forward facing eyes. We have opposable thumbs, and rely on our stereoscopic vision much more than our sense of smell. We have highly developed brain, as do many other primates in comparison to other types of animals, and we're fantastic with tools. Our teeth our similar, we both reach maturity slowly, and females and males have different body characteristics. However, only humans: have such intelligent and large brains, have lost most of their hairy covering, walk upright, farm the land, and process milk from cows to drink.
    As for the order in which we evolved bigger brains, bipedalism, and our teeth, I postulate the following: Our bipedalism came first, something that both homo sapiens and homo erectus share, then later our brains, because with increased intelligence we able to increase the meat uptake in our diet, which gave us the teeth that we have today.
    Are we done evolving? Yes and no. It is true that with our technology and medicine, many of the environmental pressures that once threatened our existence are no longer considered fatal, or even a threat to us. And many of the diseases and conditions that eventually kill us only take action years after reproduction, so by that time our genes have already passed on. We have used our brain to remove us from the normal progression of natural evolution, however, we now have a very different tool at our disposal: Technology. Technology has become our missing limbs, our hearing aides as we age, and in some cases, augmentation of our brains themselves. As technology improves, our genetics will not evolve, yet technology and our species will merge in ways that we can't even imagine. True, this is not the evolution that Darwin describes in his theory, yet biomedical engineering is paving the way into creating machines that help pump our hearts, allow us to see, and everything else in between. At the rate that our species is progressing, our genes will not evolve significantly in the years to come, but our species will develop powers straight out of science fiction stories as our bodies and the technology that we have created slowly merge.