Paleogenomics, Neanderthals, and Denisovans

Introduction

You have now watched all three episodes of "Becoming Human," a documentary series on human evolution.  In the previous module, we watched the first two episodes and in our introduction to the first episode there was a brief discussion of one of the claims presented, namely that research showed the brain of early hominins had similarities to human brains that living primates like chimpanzees do not.  Remember from that discussion that the claims presented in the video were criticized in peer-reviewed research that came out after the video aired.

You have just completed watching the final episode of the series on Neanderthals and modern humans, "Last Human Standing."  However, when the documentary aired in 2009, the research on paleogenomics was only just starting and what the video claims is no longer current.  Late in the episode the narrator states, "With no evidence of interbreeding, it now seems more likely that as our population grew, we simply pushed the Neanderthals out of their environments."  Paleogenomic research since this time paints a very different picture of what happened, not only with Neanderthals, but with a second species of hominins known as the Denisovans, who are described in this Leakey Foundation podcast you can listen to for free (Links to an external site.).   Svante Pääbo, the Swedish geneticist who appeared in "Last Human Standing" has led the paleogenomic research, and with his team was responsible for the discoveries.  Many of the most significant findings since the "Becoming Human" documentary aired are discussed by Pääbo in this lecture:

Instructions

First make sure you have read chapter 11 ("Archaic Humans") of the Explorations textbook, especially the boxed discussion "Special Topic: Ancient DNA" near the end of the chapter. Once you have done that,  watch and listen to Pääbo's lecture above.  He will review the important paleogenomic discoveries. As he goes through his research timeline, you will understand why the information in the "Becoming Human" documentary is so wrong given what we now know. Although the lecture is intended for a general audience, some things he discusses will be challenging for you. This is why it is good to read the textbook chapter first.  Don't worry if you don't understand everything in the lecture, just keep listening and he will cover the essential findings.  

After you have completed  you will write a 500 word update on the what the genetics research on the Neanderthals and Denisovans now shows us about those species and about our own. In your response, you should answer the following series of questions:

• Who are the Neanderthals and the Denisovans?


• What does the "Last Human Standing " documentary say about the paleogenetic research on Neanderthals and Denisovans?  Why did the documentary get it wrong?  What has happened since the documentary aired?


• What does ancient DNA (aDNA) teach us about each of these species? Which human populations are they connected to?


• What can their genomes tell us about their population structures?


• What does this research show us about our own evolutionary trajectory as modern humans?

 As always, you are welcome to exceed the length requirement (your response should simply be more than 500 words long).  When you are finished, place a word count at the bottom of your assignment that looks like this:

[568 Words]

video  https://www.youtube.com/watch?v=w4TLaRSJN2k&feature=youtu.be