Journey of Man

Today, we finished the video I talked about in my last post. We learned why the Y chromosome is the best place to look for genetic markers. This is because, unlike the X chromosome, the Y chromosome passes unchanged from father to son, making it the genetic marker easier to follow. The narrator of this video goes from Australia to a small Indian village and takes blood samples from them because he is trying to prove that the San Bushmen tribesmen traveled through India to get to Australia. He is taking samples from this small village specifically because the more indigenous a people are, the easier they are to connect to ancestors.

We also learned about why our skin color is different. This is because people living near the equator tend to have dark skin, while light-skinned people live nearer the poles. Also, selection on skin color depends on the UV radiation levels. In the video, we met a man named Niazov who has a genetic marker that has been inherited by 2,000 generations. Next, we met the Chuchki, a nomadic tribe, who are distant cousins of the Native Americans. They live by the Arctic Circle and have grown very accustomed to the freezing temperatures. In fact, they seem to have evolved or adapted in a way to survive int these harsh conditions. They adapted to a smaller sized body to reduce surface area in which heat can be lost. Moreover, their whole body contains body heat. The narrator finally came to the end with the Native Americans. Did you know that the first Americans to arrive on this continent arrived 13,000 years ago? It's crazy! Until next time...