Woolly mammoths were characterized by their fur and his small ears. These and other traits were already genetically encoded in the first specimens, but were defined over the 700,000 years of the species’ existence roaming the steppes siberian.
A study by Swedish researchers that ‘Current Biology’ publishes this Friday found 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 first ones unique, as individuals and as a species.
Woolly mammoths have some very distinctive morphological features, but there are many other adaptations such as the metabolism of fats and the perception of coldthat they are not so obvious because they are at the molecular level, explained the first author of the study, David Diez, of the Center for Paleogenetics of Stockholm. The team had the genome 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.
Chukochya genome could not be identified genes that evolved throughout the life of the species, thus it can be affirmed that its members are uniquely specific to woolly mammoths and did not exist in their ancestors, added the also signatory Love Dalén. The genome of that first known specimen was shared by approximately 91.7% of those affected 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 worn and fluffy than that of later woolly mammoths,» Dalén added.
The study identified a gene with several changes that may have been responsible for their tiny ears, but also others related to living in cold environments and shared by them. mammals unrelated current articles. Some «highly evolved genes related to metabolism and fat storage are also found in arctic species such as reindeers and polar bearswhich means that there is probably a convergent evolution of these genes in cold-adapted mammals”, stated Díez.
The more modern woolly mammoths also exhibited various compromised immunity in resistances of T cellsthat were not seen in their ancestor and the authors speculate that these may have conferred enhanced cellular immunity in response to pathological 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.