Convergent Mutations and Single Nucleotide Variants in Mitochondrial Genomes of Modern Humans and Neanderthals

The genetic contributions of Neanderthals to the modern human genome have been evidenced by the comparison of present-day human genomes with paleogenomes. Neanderthal signatures in extant human genomes are attributed to intercrosses between Neanderthals and archaic anatomically modern humans (AMHs). Although Neanderthal signatures are well documented in the nuclear genome, it has been proposed that there is no contribution of Neanderthal mitochondrial DNA to contemporary human genomes. Here we show that modern human mitochondrial genomes contain 66 potential Neanderthal signatures, or Neanderthal single nucleotide variants (N-SNVs), of which 36 lie in coding regions and 7 result in nonsynonymous changes. Seven N-SNVs are associated with traits such as cycling vomiting syndrome, Alzheimer's disease and Parkinson's disease, and two N-SNVs are associated with intelligence quotient. Based on recombination tests, principal component analysis (PCA) and the complete absence of these N-SNVs in 41 archaic AMH mitogenomes, we conclude that convergent evolution, and not recombination, explains the presence of N-SNVs in present-day human mitogenomes.

Living science: Science as an activity of living beings

The philosophy of science should accommodate itself to the facts of human existence, using all aspects of human experience to adapt more effectively, as individuals, species, and global ecosystem. This has several implications: (1) Our nature as sentient beings interacting with other sentient beings requires the use of phenomenological methods to investigate consciousness. (2) Our embodied, situated, purposeful physical interactions with the world are the foundation of scientific understanding. (3) Aristotle's four causes are essential for understanding living systems and, in particular, the final cause aids understanding the role of humankind, and especially science, in the global ecosystem. (4) In order to fulfill this role well, scientists need to employ the full panoply of human faculties. These include the consciousness faculties (thinking, sensation, feeling, intuition), and therefore, as advocated by many famous scientists, we should cultivate our aesthetic sense, emotions, imagination, and intuition. Our unconscious faculties include archetypal structures common to all humans, which can guide scientific discovery. By striving to engage the whole of human nature, science will fulfill better its function for humans and the global ecosystem.

Cross-comparison of the genome sequences from human, chimpanzee, Neanderthal and a Denisovan hominin identifies novel potentially compensated mutations

The recent publication of the draft genome sequences of the Neanderthal and a ~50,000-year-old archaic hominin from Denisova Cave in southern Siberia has ushered in a new age in molecular archaeology. We previously cross-compared the human, chimpanzee and Neanderthal genome sequences with respect to a set of disease-causing/disease-associated missense and regulatory mutations (Human Gene Mutation Database) and succeeded in identifying genetic variants which, although apparently pathogenic in humans, may represent a 'compensated' wild-type state in at least one of the other two species. Here, in an attempt to identify further 'potentially compensated mutations' (PCMs) of interest, we have compared our dataset of disease-causing/disease-associated mutations with their corresponding nucleotide positions in the Denisovan hominin, Neanderthal and chimpanzee genomes. Of the 15 human putatively disease-causing mutations that were found to be compensated in chimpanzee, Denisovan or Neanderthal, only a solitary F5 variant (Val1736Met) was specific to the Denisovan. In humans, this missense mutation is associated with activated protein C resistance and an increased risk of thromboembolism and recurrent miscarriage. It is unclear at this juncture whether this variant was indeed a PCM in the Denisovan or whether it could instead have been associated with disease in this ancient hominin.