Last week we learned about hominids, which include animals such as gorillas, chimpanzees, orangutans, and human beings. Hominins are part of the hominids but specifically refers to any species of early human that is more closely related to humans than apes. A main trait that distinguishes hominins from hominids is the fact that hominins are bipedal, which means they stand and walk on two legs. This trait is advantageous because it gives one the ability to travel faster and therefore allow them to hunt for more food or evade predators. It was also discussed that bipedal trait may have had a hand in allowing for the larger brain sizes that we see in humans today. Brain size is a trait I want to discuss because the brain size of hominins is actually relatively small in comparison to their head size. However, having larger heads could be the reason why our brains where able to evolve to be bigger over the millions of years. Those with larger brains were superior and had more cognitive functions allowing them to live longer and pass on the trait. Another trait that can inform us about modern human biology is the arm to leg length ratio of the A. Garhi. The ratio is very similar to the ratio we see in modern humans, who have fairly long legs in relation to their arms. Most other hominins at the time have long arms due to still living in trees. Therefore, having a hominin that has a variation in the trait can show us where modern humans might have acquired their trait from. Looking at all these traits helps anthropologist form a relationship between species and allows them to form a path that human’s evolution took. Each hominin provides a picture of how humans acquired certain traits and with every new fossil discovery contributes to the knowledge of our past.
It was really interesting this week to look at Paleoanthropology and how fossil remains give clues to the evolutionary history of humans. First, fossils are cast of bones, so there usually is no way to get any DNA from them. Instead paleoanthropologist look at the shape and size of fossils to gather information about the subject. The first thing anthropologist can learn from fossilized skeletal remains is creating a time line of the different branches of species and where they diverge. This allows us to see when each trait appeared and how it has evolved overtime to be what humans have today. Not only does the fossil show traits of the species but the sediment around the fossil can give insight into the environments that led to the changes. Reconstructing the past is so important because it helps us understand the traits we have today.
Hey! I liked how you agree that reconstructing the past is so important. I also think this because the past shows us how our species has evolved to survive. Without looking at the past, we would be ignorant and could go back to traits that served us no purpose. I also liked how you addressed that we can learn about the environment as well as species. The trait that was the most interesting and important to me is bipedalism because I think there are so many cool advantages with this trait. I do not think I could never not use it! Other traits I talked about include teeth size and how they have changed as well as brain size. I had no idea they had such tiny brains!
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Hi devonshire! i really enjoyed your take on some of the defining characteristics of us humans. Almost all of us mentioned bipedalism as its the most obvious characteristic. But i loved your comments and opinions on the ratio of head size to brain size. It makes sense that bigger brains mean higher intelligence and superiority but what i really found interesting was your inference about how our larger head size could be the reason for our increased brain size, that one caused the other, which is basically evolution in a nutshell! I also loved your comments about the A. Garhi and their arm to leg length ratio. In the lectures, it was also stated that they were the first species to also be found with evidence of tools. I wonder if theirs a correlation between the two!