Woolly mammoths were characterized by their fur and his small ears. These and other traits were already genetically encoded in the first specimens, but they were defined throughout the 700,000 years of existence of the species wandering the steppes siberianas.
A study by Swedish researchers that ‘Current Biology’ publishes this Friday examined and compared genomes of woolly mammoths, from the first specimens to the most modern. They crossed them with others of elephants contemporary Africans and Asians to discover what made the former unique, as individuals and as a species.
Woolly mammoths had some very distinctive morphological features, but there are many other adaptations such as the metabolism of fats and the perception of coldwhich are not as obvious because they are at the molecular level, explained the study’s first author, David Diez, of the Center for Paleogenetics at Stockholm. The team had the genomes of 23 woolly mammoths that had lived in the last 100,000 years, except for one that corresponds to Chukochyaone of the oldest known, from about 700,000 years ago.
unique mutations
The Chukochya genome allowed us to identify genes that evolved throughout the life of the species, so it can be said that their specific mutations are unique to woolly mammoths and did not exist in their ancestors, added the also signatory Love Dalén. The genome of that first known specimen shared approximately 91.7% of the mutations that caused changes in the coding of proteins in more modern woolly mammoths.
This means that many of the traits that define the speciesincluding the fur bulk, fat metabolism, and the ability to sense cold were probably already present when it first diverged from its ancestor, the steppe mammoth, and evolved. The earliest woolly mammoths may have had “the ears larger and their wool was different, perhaps less insulating and fluffy than that of later woolly mammoths,” added Dalén.
arctic species
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The study identified a gene with several mutations that may have been responsible for their tiny ears, but also others related to living in cold environments and sharing them. mammals unrelated current arctic. Some “highly evolved genes related to metabolism and fat storage are also found in arctic species such as reindeer y polar bearswhich means that there is probably a convergent evolution of these genes in cold-adapted mammals,” Díez said.
Newer woolly mammoths also carried several immune mutations in antigens of T cellswhich were not seen in their ancestor and the authors speculate that they may have conferred enhanced cellular immunity in response to pathogens emerging viruses. In this study all genomes were found in Siberiabut the researchers hope to be able to compare with other woolly mammoths from North America in the future.