Hominins

Phylogenetic relationships of the archaic fragments sequenced in Icelanders

An article published in the journal “Nature” reports a genetic study carried out using data obtained from 27,566 Icelanders to understand which parts of modern humans’ genome contain genes inherited from Neanderthals following interbreedings, and what role it plays in modern humans. A team of researchers performed a comparative analysis with hominin genomes sequenced at the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig, Germany, finding many different genes scattered in the Icelandic genomes. By putting them together, they reconstructed at least 38% of the Neanderthal genome using 14 million fragments. A surprise came from the discovery of Denisovans genes, usually present in Asian populations, but it’s possible that they too were inherited from Neanderthals who descended from interbreedings with Denisova.

Homo antecessor bones (Image courtesy José María Bermúdez de Castro)

An article published in the journal “Nature” reports a study based on the extraction of proteins from a tooth about 800,000 years old attributed to the species Homo antecessor. A team of researchers used a mass spectrometry technique to obtain that information, very useful for a better understanding of the relationships among the various human species. The conclusion is that Homo antecessor could be closely related to the last common ancestor of Homo sapiens, Neanderthals and Denisovans.

Little Foot's skull

An article published in the journal “Scientific Reports” reports a study on the characteristics of the skull of the specimen of Australopithecus nicknamed “Little Foot” that offers information on this species’ life. A team of researchers from Wits University led by Dr Amélie Beaudet examined a 3D reproduction of the fossil generated by subjecting it to a high resolution micro-CT scan. The presence of the first cervical vertebra has a crucial role in the biology of vertebrates and the Little Foot’s one is in its place offering information on the possible head movements for this species of Australopithecus, different from those possible for modern humans.

Entrance of the Chagyrskaya Cave (Photo courtesy K. Kolobova/Institute of Archeology and Ethnography of the Siberian Branch of the RAS)

An article published in the journal “Proceedings of the National Academy of Sciences” reports a study on Neanderthal migrations to Siberia. A team of researchers excavated the Chagyrskaya Cave in the Altai Mountains in Siberia, finding 90,000 artifacts and 74 Neanderthal fossils along with bone tools, animal and plants remains in deposits dated between 49,000 and 59,000 years ago. The tools have distinctive characteristics remarkably similar to those of Neanderthal artifacts from Eastern Europe, while nothing like this has been found at other sites in the Altai Mountains occupied by Neanderthals. Such archaeological evidence, combined with genetic studies on well-preserved Neanderthal fossils, indicate that there were at least two migrations of these hominins to Siberia, the first one over 100,000 years ago.

Evolutionary tree showing interbreedings between hominins

An article published in the journal “Science Advances” reports the traces of an interbreeding between the ancestors of Neanderthals and Denisovans with a population belonging to another species of hominins called superarchaics because they probably separated from other humans about 2 million years ago. A team of researchers led by anthropologist Alan Rogers studied the ways in which mutations are shared between various populations of Homo sapiens, Neanderthals and Denisovans, concluding that certain sharing patterns indicate that there were five episodes of interbreeding between species including the one occurred over 700,000 years ago between superarchaic hominins and ancestors of Neanderthals and Denisovans.