Analysis of Neandertal genome

CREATED: 201005071603 LINK: url:/home/melvin/Modules/Literature/Green2010.pdf

If Neandertals are on average most closely related to present-dat human in certain parts of the world then in others, this would strongly suggest that Neandertails exchanged parts of their genome with the ancestors of this group.

Challenges in sequencing of ancient DNA:

• DNA is degraded to a small average size of less than 200bp
• it is chemically modified
• extracts almost always contain only small amounts of DNA from microbial
• organisms that colonized the specimens after death

It is necessary to identify the DNA molecules that are from neandertal by comparing against the human and chimp genome.

Analyze Neandertal segmental duplications by measuring excess read-depth to identify and predict the copy number of duplicated sequences, defined as those with >95% sequence identity.

Neandertals are on average closer to individuals in Eurasia than to individuals in Africa. They may be explained by mixing of early humans ancestral to present-day non-Africans with Neandertails in the Middle East before their expansion into Eurasia.

Another scenario is that the ancestral population of present-day non-Africans was more closely related to Neandertals than the ancestral population of present-day Africans due to ancient substructure within Africa.

Neandertals are likely to have had a role in the genetic ancestry of present-day humans outside of Africa, however this role was relatively minor given that only a few percent of the genomes of present-day people outside Africa are derived from Neandertals.

A number of regions genomic regions, such as those involved in cognitive abilities and cranial morphology, are candidates for positive selection early in modern human history.