An international team of geneticists and archaeologists led by the Francis Crick Institute (UK) ancestors of dogs can be traced back to at least two ancient wolf populations. As such, these domesticated animals would be more closely related to the Ice Age wolves of eastern Eurasia than to the western ones, according to an analysis of the genomes of gray wolves from Europe, Siberia, and the North over the past 100,000 years. America..
“We need to find these dogs They are more closely related to the prehistoric wolves of Asia than to those of Europe. suggests that the domestication process will take place somewhere in Asia. We can’t say exactly where, because we don’t have ancient wolf genomes from most of the continent. But we think being able to pinpoint the origin of dogs is an important step”, Anders Bergström, co-author of the study published in the journalism Nature.
For researchers, this study represents one more step towards the discovery of the mystery of the domestication of dogs, One of the biggest unanswered questions about human prehistory. Scientists were able to detect natural selection during the late Pleistocene, about 129,000 to 11,700 years ago.
“Studying the genomes of ancient wolves allows us to understand how these predators are genetically related to each other and to dogs, but not biologically. So we can’t say much about the traits of wolves that gave birth to dogs,” says Bergström.
what yes what is known for sure, the gray wolf (canis lupus) was the first species to give rise to a native population and was present in most of the Northern Hemisphere during the last Ice Age, when many other large mammals became extinct. Domestication would have occurred at least 15,000 years ago.
Sequencing of 72 ancient wolf genomes
To learn more about its history, The team sequenced 66 new genomes from ancient wolves from Europe, Siberia, and the northwestern Americas.and contained five wolf genomes and one dhole genome (a wild dog native to central, southern, eastern and southeast Asia) previously sequenced from the Caucasus in the last 100,000 years. Among the remains is the complete and perfectly preserved head of a Siberian wolf that lived 32,000 years ago.
Fossils from previously excavated prehistoric wolves and archaeologists from 38 institutions in 16 different countries participated in the study. Nine ancient DNA labs then collaborated to generate DNA sequence data from wolves.
“Our goal was to get as large a sample of ancient wolves as possible. however, there are great differences between different parts of the world in the availability of these animals and the preservation of their DNA. In many remains, it has simply not been preserved, so such work involves analyzing many different fossils and getting lucky with some,” says the expert.
The fact that most of the ancient wolf genomes in this study came from northern latitudes, a reflection of how DNA is better preserved in colder climates.
Unknowns about the double offspring still open
Analyzing the genomes, the researchers found that both early and modern dogs were genetically more similar to ancient wolves in Asia than those in Europe. domestication somewhere in the east.
you stillThey also found evidence that two different populations of wolves contributed DNA to dogs.. The earliest ones from northeastern Europe, Siberia, and the Americas seem to have a single, common origin with the eastern source. But those from the Middle East, Africa and Southern Europe will have an ancestry from another source related to Middle Eastern wolves in addition to the Eastern source.
One possible explanation for this double ancestry is the multiple domestication of wolves and mixing of different populations. Another possibility is that domestication occurred only once, and double ancestry these first dogs will mix wild wolves. It is currently not possible to determine which of these two hypotheses has come true.
“Through this project, we have greatly increased the number of sequenced ancient wolf genomes, allowing us to build a detailed picture of wolf ancestry over time, even around the dog’s origins,” Bergstrom emphasizes.
Natural selection and genetic mutations
They also found that wolf populations were genetically linked during the Late Pleistocene, possibly due to the wolves’ ability to move across open terrain.
This link between wolf populations is due to the authors’ natural selection, particularly Mutations in the IFT88 gene Between 40,000 and 30,000 years ago, this may have contributed to the survival of the species. The properties of IFT88 responsible for this survival advantage remain unclear.
“We know from studies in mice and humans that the IFT88 gene plays a role in skull and jaw development. While we are not sure why natural selection targeted this gene in Ice Age wolves. We speculate that it may have reflected some. morphological adaptationperhaps in response to changes in prey availability or hunting strategies,” says Bergström.
Many potential prey species went extinct during the Ice Age. Changes in facial or jaw morphology conferred by mutations in IFT88 could have allowed wolves to adapt to new conditions during this ecologically turbulent time.
For Pontus Skoglund, co-author and group leader of the Ancient Genomics lab at Crick: “This is the first time that scientists have directly followed natural selection in a large animal over a 100,000-year timescale, seeing how evolution has evolved. Trying to reconstruct it from existing DNA. instead of real time.”
The team continues to search ancient close ancestor of the wolf the number of dogs that can reveal more precisely where domestication took place. They are now focusing on genomes from other locations that were not included in this study, including more southern regions.
……
Environment department contact address:crisclimatica@prensaiberica.es
Source: Informacion
