Troglodyte

Today's edition of Science includes the article, "A Draft Sequence of the Neandertal Genome." The aptly titled article not only describes this rough sequence of the neandertal genome, but offers particularly intriguing commentary on the difficulties of ancient DNA retrieval. Yet, most importantly, the article compares the genome of Homo neanderthalensis with that of five modern humans.

Only recent advances have permitted ancient DNA retrieval. In spite of this, problems persist as remains are replete with microbial colonization. The natural process of putrefaction introduces the DNA of microbes which begin to interfere. Roughly 95-99% of the samples were comprised of microbe DNA, which had to be treated with enzymes to "enrich" the samples such that the ratio of neandertal DNA was accessible. Further, a close genetic "relative" must serve as a basis of comparison to ensure the research is on track. It then logically follows that sequencing the neandertal genome would imply an analysis with respect to modern humans.

Insodoing, DNA samples were collected from 21 late Pleistocene (±38,000 year-old) bones of three neandertal women discovered in Croatia's Vindija Cave and compared to samples from five individuals from China, France, Papua New Guinea, Southern Africa, and Western Africa. The genome was analyzed across genetic "hotspots" derived from known deviations between chimpanzee and human DNA. The results suggested that neandertals fall within the degree of genetic variation found in modern humans. There were only five genes found to be distinctly modern human. Interestingly, there was greater variation amongst the neandertal genome when compared to those of the modern human genomes from both African individuals than all non-African samplings.

Considerable speculation on the potential for human and neandertal cross-breeding has circulated academia with regard to hominid evolution for some time. Nonetheless, the hope that this study could formulate a conclusive posit on the notion is unfulfilled. The article suggests that based upon the research, neandertal and human divergence from a common ancestor is too recent to confirm or deny any definitive understanding for the genomic overlap.