The Concepts of 'Species' and 'Population' in Considering Ancient DNA and Building Phylogenetic Trees of Hominid Evolution

Abstract

A number of recent articles have appeared on the hominin Denisova fossil remains. Many of them focus on attempts to produce DNA sequences from the extracted samples. Often these project mtDNA sequences from the fossil remains of a number of Neandertal fossils and the Denisovans in an attempt to understand the evolution of Mid Pleistocene human ancestors. One of these recently appeared in Science by Vernot et al. 2016. There are two problems with these papers, one concerns the degradation of the ancient DNA and its interpretation as authentic genetic information and the other concerns the idea of “species” versus that of “population” and the use of these ideas in the building of evolutionary diagrams to indicate ancestry and extinction. A central issue is what does human variation mean, how much population variation has there been in the past and how does this variation distinguish hominid speciation or simply a process of anagenesis.