When I started my Bones, Stones, and Human Evolution class at Mesa Community College, I thought I had a good understanding of evolution and Natural Selection. I mean, I have read things here and there and watched the Discovery Channel, that made me an expert in my mind. Can’t blame me, because it turns out that our minds were the last thing to evolve, which is something I didn’t know until I took this class. The truth is, I didn’t learn as much about human origins as much as I learned how little I know about our origins. Learning that the time line of and how we developed is not something that is currently set in stone. Our collective knowledge about our origins is truly amazing when considering how lucky we are to have found the evidence that we have. Everyday we learn something new and every time we do, we answer one question and seem to have a thousand new ones. It is as if we are the greyhound and our origins are the stuffed rabbit that is always just out of reach. If I had to choose what the most valuable lesson of this class was, I would say that it was that we know we evolved from some kind of primate and that natural selection was the designer, but that we are just barely discovering the specifics of our evolution. This is truly an amazing time of discovery and I can’t wait till I am a part of it.

While we were studying our hominid ancestors, a new discovery was made, Ardipithecus. This new Paranthropus was added to our studies and was an example of how things change. Many anthropologist theorize that we evolved from chimpanzees but the more we discover, the more likely this was not the case. We may share a common ancestor but after the discovery of Ardipithecus, we are not finding that we share enough with Chimps. For one, they are knuckle walkers and Ardipithecus does not seem to have any signs of ever knuckle walking. Our separate lineage with Chimps may be far older than we originally thought.

In class we were able to get a glimpse of how we evolved by just studying all the other primates on the planet. There are primates of all different types, sizes and environments. It is very possible that our oldest ancestors were a primate similar to small monkeys that later developed into other larger primates. Perhaps those primates developed social systems similar to the kinds we share with baboons and maybe that was the beginnings of our brains evolution. Maybe that animal evolved into a tree walking primate like the orangutans. Before Ardipithecus, I might have said Chimpanzees but now it seems that our direct ancestor walked in the trees instead of on its knuckles. I say maybe it was something like the tree walking orangutans but as of yet, no on knows. Perhaps our ancestor developed similar to Chimpanzees and grew more intelligent like they have and started eating meat for the same reasons the chimps eat meat. Perhaps our ancestors lost their large fangs because our females chose to breed with less aggressive males, like the highly aggressive males we seen in chimpanzee groups or tribes. Maybe that is why ours have virtually disappeared while all other primates still have them. We continue to find new fossils like Ardipithecus which helps us answer some of our questions, but until we have more artifacts, the study of primates is revealing a lot to us.

The biggest one of these unanswered questions would be, why are we bipedal? In class we learned a great deal about primate bone structures and how it relates to our own. While we are closest to the skeleton of a Chimpanzee, our bones still have similarities with all primates. Some noticeable differences are that, primates have longer arms compared to their body size and they have a Sagittal Crest that allows them to eat hard plants. Another major difference between us and other primates is our pelvis. We are bipedal, so we require a more bowl shape when compared to the longer primate pelvises. While we need our ribs and pelvis to be balanced other primates need them to be more flexible for swinging in the trees.
Still none of that answers the question, why are we bipedal? One theory we learned was about was heat absorption. An experiment showed that by being bipedal we expose less of our bodies to direct sunlight which keeps us cooler. Do to natural selection, we became better at cooling ourselves. We lost our fur and started sweating, no other primate sweats. This points to an animal that was more successful  because it cooled itself better. Studying the skulls of hominids showed that we developed better ways of controlling blood flow to the brain, and as we became human we became better at cooling our brains through blood flow. Some people even theorize that the cooling of our brains may be one of the causes for the development of a larger smarter mind.

According to the fossils we have found, many different types of hominids existed at the same time and were the most successful. Some of the later types of hominids have such similar fossils to us that it becomes harder and harder to tell us from them. The one thing we know for certain is that us humans have been more successful than our extinct hominid cousins and ancestors.

There is one major and obvious difference, our ability to make art. Art is truly the thing that makes us say, “this person was human.” We have found cave and rock art all around the world and they share similarities with one another. We know that people had language by the simple act of making art. Art requires the ability to think in the abstract. You have to be able to say that one thing represents another and it is the basis of our languages. We make sounds that represent something else, and we are able to understand that meaning. No other animal or hominid has had this ability and it maybe why our hominid cousins, the neanderthal, did not survive while we did. We don’t know for certain, but I suspect that one day we will discover the answer.
While we were not the first hominids to leave our home base of Africa, we certainly did leave and learned to adapt to all other environments. As we left Africa our tools began evolving faster and faster. Our populations are abundant because culture and tool use made us more successful. Today, we are 99.9% the same according to genetics and are not that  much different than the first people who left Africa, yet we now wield the power of the atom and the electron.

It took our species millions of years to evolve from a tree walking primate into the varying cultures and booming cites of today. Even now that we have developed car driving and space exploring societies, we can recognize our lineage in our everyday lives. We still war like Chimpanzees, we still have a sweet tooth and crave fat even when we have reached our daily need. We still display aggressiveness. We even share cultural responses to populations size with the Japanese Macaque.

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These are just some of the things I have learned in Bones Stones and Human Evolution; the other major part of the class is learning how to think scientifically and how to do your own experiments. We learned about dating archeological sites using techniques such as dating using the depletion of carbon 14, dating by counting and comparing tree rings, dating using the topography, and dating by comparing fossils to pig fossils. (Pigs adapt quickly to their environments so you can use the changes in their fossils as a way of dating when you compare it to climatic changes.) We learned that anthropology really is interdisciplinary and brings in other sciences such as genetics, geology, and forensics. We learned how to properly come up with research projects. We learned the basics of digging at an archeological site. In short, we learn what the scientific community has learned about evolution, how they learned it, and how to go about thinking of new ways of learning more.

As I reflect back on all of the things I have learned in Bones Stones and Human Evolution, I think the most important thing was that theories are very powerful things. That we landed on the moon based on our theories. While there is a trend for people to act as if theories are just guesses, I learned not only how powerful they can be, but what actually makes them qualify as a theory. They are no mere guesses. Theories are a purposed answer to a question that is testable and has not been disproved by a test.

I have become satisfied that I have learned something useful to my future and understanding of my world. To bad more people don’t take anthropology classes. Maybe seeing data and learning about its collection would end some of the doubt brought on by religious zealots and give a stronger voice to the more educated among the clergy and religious spokespeople.