Honors Bio Class 18

Today in class we finished watching a movie about the origin of man, and how we were able to populate the entire planet. Last class we left off at Australia, the place where man supposedly traveled to after leaving Africa. However, the narrator found proof in India that our ancient ancestors had indeed passed through India to get to Australia. He found this proof in a man among a remote village on the outskirts of India that had a similar mutation in his DNA in relation to our ancestors DNA. The reason why the narrator was only testing men was because of the Y chromosome. The Y chromosome is special because it does not change when it is transferred to offspring and would provide untainted proof. 

After Australia, the narrator studied the movement of the second group of ancestors that instead moved through Central Asia and Europe. We see proof that our ancestors moved through Pakistan, and Afghanistan through the study of one mans blood, Niazov. 

This man had DNA that could be traced back to the original group of ancestors that had made the trek from Africa to Afghanistan. from this point on, it took humans 10,000 years longer to get to Europe because of the drought caused by the ice age. However once they reached Europe and the Arctic Circle many physical changes took place. One of the most noticeable changes was the color of skin. Dark skin was for people that lived in an environment that had constant sunlight where dark skin could offer protection. Light skin on the other hand, was for places with less sunlight so that the skin could pick up as much sunlight as possible in order to receive nutrients.