Denisovans, Melanesians, Europeans, and Neandertals: The Confusion of DNA Assumptions and the Biological Species Concept.

A number of recent articles have appeared on the Denisova fossil remains and attempts to produce DNA sequences from them. One of these recently appeared in Science by Vernot et al. (Science 352:235-239, 2016). We would like to advance an alternative interpretation of the data presented. One concerns the problem of contamination/degradation of the determined DNA sequenced. Just as the publication of the first Neandertal sequence included an interpretation that argued that Neandertals had not contributed any genes to modern humans, the Denisovan interpretation has considerable influence on ideas regarding human evolution. The new papers, however, confuse established ideas concerning the nature of species, as well as the use of terms like premodern, Archaic Homo, and Homo heidelbergensis. Examination of these problems presents a solution by means of reinterpreting the results. Given the claims for gene transfer among a number of Mid Pleistocene hominids, it may be time to reexamine the idea of anagenesis in hominid evolution.