According to a recent study, traits such as thick and fluffy coats were genetically encoded and became increasingly prominent as woolly mammoths adapted to the harsh climate of Siberia.
|Mammoths' bodies evolved in response to their environment, allowing them to better retain heat, as evidenced by their thick coats. Photo credit: David Fleetham/Alamy.|
A new study suggests that traits such as fluffy coats, large fat deposits, and smaller ears of woolly mammoths became more pronounced over 700,000 years as they adapted to the harsh Siberian climate.
The genomes of 23 Siberian woolly mammoths were compared to those of 28 modern-day elephants, revealing that many of the mammoths' distinctive traits were already genetically encoded in the earliest specimens. However, their bodies continued to evolve in response to the environment, allowing them to better retain heat.
According to Love Dalén, a professor of evolutionary genomics at the Centre for Palaeogenetics in Stockholm and senior author of the study, the earliest woolly mammoths possibly had larger ears and their wool was different from later woolly mammoths, perhaps being less insulating and fluffy.
|Love Dalén commented on the study, stating that "This allows us to study evolution in real-time." Photo credit: Ian Watts/PA.|
The study's senior author, Love Dalén, explained that by comparing the genome of a 700,000-year-old woolly mammoth named Chukochya with those of 22 relatively modern woolly mammoths that lived within the past 100,000 years, researchers were able to trace the evolution of mammoth genes over time.
According to Dalén, this approach allows scientists to study evolution in real-time and identify unique mutations that are specific to woolly mammoths.
The study revealed that many genes that were adaptive for woolly mammoths were related to living in cold environments, and some of these genes were also shared by other unrelated Arctic mammals such as polar bears and reindeer.
David Díez-del-Molino, the lead author of the study and also from the Centre for Palaeogenetics, explained that the team aimed to uncover the genetic makeup that distinguishes a woolly mammoth from other species.
While woolly mammoths are recognized for their distinctive features such as thick fur and small ears, there are other adaptations, such as fat metabolism and cold perception, that occur at the molecular level and are less apparent.
The study, which was published in Current Biology, analyzed 16 previously unsequenced genomes and discovered a gene with several mutations that could have contributed to the animal's small ears.
The Chukochya genome, which is 700,000 years old, was found to share about 91.7% of the mutations that led to changes in the more recent woolly mammoths. This suggests that many of the distinguishing features of woolly mammoths were already present when they first diverged from their ancestor, the steppe mammoth.
The study presented several practical challenges, according to Dalén. In addition to fieldwork that involved dealing with polar bears and mosquitoes, the researchers had to work in an ancient DNA laboratory. This required wearing a full-body suit with a hood, face mask, visor, and double gloves, which made the lab work quite uncomfortable.