The geographic review of Homo sapien - An update!

This post is a follow on to the review posted on Friday the 9th of November (you might want to brush up a bit before you read on so I don't leave you behind). In our first look into where on earth our species comes from I took you on a tour through the groundbreaking primary papers which first furnished the theories with scientific evidence. However as is always the case with science, things move on rapidly; new research comes out all the time, slowly allowing us to sift out all the falsities thereby allowing the thousands of year old tale to be told.

When I last left you it was with the notion that the best supported view of the scientific community was that of the Out of Africa hypothesis. The Multiregional theory being blown out of the water by mitochondrial DNA evidence. However new research muddies this clear distinction (things in science are never as simple as they seem).

Recent scientific advancements now allow us to sequence the genomes of the most recent species of Hominin we shared the world with. These include the Neanderthals and the Denisovians. The results of these studies were published by Green et al. and Reich et al. respectively in 2010. The findings of which are discussed by Svante Paabo in the video below.

The Out of Africa hypothesis is defined as a total replacement of the local populations by Homo sapien with NO interbreeding, whereas the Multiregional hypothesis proposes an independent evolution of modern from indigenous Hominin species. The new research suggests a compromise between the two extremes; H.sapiens did emerge from Africa to conquer the world but they got jiggy with the locals too, and in doing so enabled the preservation of an extinct species to live on in us today .

Figure 1 H. sapien falls for a Neanderthal

This all seems fine and dandy, however calculating these findings is error prone. From information gained in previous molecular biology modules I understand there to be many complexities and problems encountered sequencing ancient DNA; in some instances the DNA is contaminated and the strands being sequenced are in actual fact the genetic material of the researcher. The two studies mentioned above have undergone rigorous peer reviewing and therefore the results are much more reliable, for the time being it is to be believed that Europeans share 1-4% of DNA with Neanderthal man and Melanesians share 4-6% of DNA with Denisovans; the question is how Neanderthal are you?