paleontology

Although it is accepted that the impact of a large meteorite was what caused the extinction of the non-avian dinosaurs at the end of the Cretaceous, there are various theories as to whether their disappearance was sudden or if their population was already in gradual decline. An international team with Spanish participation has analyzed new fossil data from northern New Mexico (USA) and concluded that they were not in decline, but were abruptly exterminated by the impact that occurred some 66 million years ago. The results are published in the journal Science.  

A fragment of a human face discovered in 2022 at the Sima del Elefante site in the Sierra de Atapuerca (Burgos) and dated to between 1.1 and 1.4 million years ago represents the oldest known face in Western Europe. The fossil, nicknamed ‘Pink’, does not belong to Homo antecessor, but has been provisionally catalogued as Homo affinis erectus. The find, which is published in the journal Nature, could indicate that Western Europe was populated by at least two species of hominids during the Early Pleistocene: Homo affinis erectus and, later, Homo antecessor.

A team of researchers has analyzed more than 300 human genomes from the last 50,000 years and has concluded that most of the gene flow we received from Neanderthals is attributable to a single period, which probably occurred between 50,500 and 43,500 years ago. In addition, Neanderthal inheritance underwent rapid natural selection in subsequent generations, especially on the X chromosome, according to a study published in Science.

At least two hominin species - Homoerectus and Paranthropus boisei- coexisted in Kenya's Turkana Basin around 1.5 million years ago, a study published in Science confirms. The authors describe the first physical evidence of this coexistence in the form of footprints, found at several sites in the area.

An international team of scientists, including researchers from the CRG and the CNAG (Barcelona), have managed to recover DNA remains from a female woolly mammoth that died in Siberia 52,000 years ago. The novelty is that, for the first time, the remains conserve the three-dimensional structure in the form of chromosomes, which makes it possible to investigate the genes that were active. According to one of the authors of the study, the results of which are published in the journal Cell, this type of discovery "changes the rules of the game, because knowing the shape of the chromosomes of an organism allows us to assemble the entire DNA sequence of extinct creatures and obtain information that was not possible before".

The Anthropocene Working Group of the International Commission on Stratigraphy has  proposed Crawford Lake in Canada as a reference site for studying the Anthropocene as a possible geological epoch. This proposal for a Global boundary and Stratotype Section and Point (GSSP) was presented today at the International Congress of Stratigraphy in Lille, France. It is a necessary, but not sufficient step for the Anthropocene to enter the International Chronostratigraphic Table, the worldwide reference for geological units. Once approved by the AWG, this proposal has to go through three more votes in international geological bodies. 

Modern humans may have coexisted with Neanderthals in northern Spain and France between 1,400 and 2,900 years before the disappearance of Neanderthals, according to a study published in Scientific Reports.

The Karolinska Institute has awarded the Nobel Prize in Medicine or Physiology to Swedish biologist Svante Pääbo, a specialist in evolutionary genetics, for his discoveries on the genomes of extinct hominids and human evolution.