Looking at different human remains and their fossil record can tell us about who we are today and how we got to this point. This week’s lectures focused on the different traits that came about, their uses, the ever changing environment that the early hominins lived in, and the different methods of dating the fossils. I found the topics this week to be really interesting, especially learning about some of the changing traits from one to the next, and the advantages and disadvantages that they had in certain environments or under certain conditions.
One trait that I found highly intriguing was the skull. The location change in the foramen magnum to be under the skull indicates that the creature would walk in a bipedal way, instead of on four legs. The skull also has a secondary trait, which is the overall size of the skull. We learned that chimps and other non-human apes typically have a relatively small brain, usually 450cc or smaller, while a modern human has a size of about 1200cc. Both the change in head size and in the foramen magnum show a progression in bipedalism, and an increase in complex thought. The change in head size also correlates with the use tools as well to show the increase in this thought. These tools help anthropologists learn how the early human thought, and how this thought grew into the modern human’s abilities of complex thought. The wide variety of earl hominins goes to show how some lines are able to adapt to the conditions around them, and how some have difficulty with it and they end up dying out.
Another trait I found interesting was the change in teeth. In early primate-like hominins you see larger canine teeth, which are useful for fighting if one were up in the trees with all of their hands occupied with holding on. As these early hominines started coming down from the trees, they no longer had such a huge need for large canines because they could do more work with their free arms and hands instead. The reduction of the canine teeth is mainly shown in Australopithecus Afarensis, which we know from the Laetoli footprints that they were bipedal and also lived in less treed locations similar to the Serengeti plains, as well as in marshy areas. In later Australopithecines you can see the transformation to more modern looking teeth, which are good for both chewing (molars), and ripping/cutting action (incisors). You can learn from the diverse environmental conditions that they lived in, that these type of teeth would be highly useful to eat a large variety of foods without expending a ton of energy trying to eat them. Anthropologists can make connections between the teeth of these individuals, and the type of foods they ate by referencing the teeth and the type of environment they may have mainly lived in. We can see from Paranthropus that they specialized in chewing, and that they spent a majority of their time doing so due to the large mandible and sagittal crest and large molars.
The large diversity of early hominins helps anthropologists gain a better understanding of how humans have evolved into their current state, and they can also get a pictures of what early traits “failed” and the reasoning on why some of these branches went extinct. I found this week’s lecture to be very interesting because of the large amount of changes that occurred with our early ancestors.