An international team of researchers analysed a skin sample from a 52,000-year-old woolly mammoth and discovered fossils of ancient chromosomes.
Associate Professor Parwinder Kaur, from The University of Western Australia and Director of DNA Zoo Australia, was co-author of the study published in Cells.
"This discovery marks a pivotal moment in our ability to reconstruct the genomes of extinct species and offers insight into their genetic makeup and evolutionary history," Associate Professor Kaur said.
"The findings suggest shortly after this mammoth's death, the sample spontaneously freeze-dried in the Siberian cold, and was preserved in a similar process to that used in the creation of beef jerky."
The preservation made it possible for ancient DNA molecules to be compared to the DNA sequences of modern species and find cases where single letters of the genetic code changed.
"The fossil chromosomes were preserved down to the nanometre scale, which opened new avenues for understanding how genes were structured and activated in ancient organisms," Associate Professor Kaur said.
"It's akin to unlocking a time capsule that not only reveals genetic blueprints but also sheds light on the biological adaptations that shaped these species over millennia."
Researchers discovered the woolly mammoth had 28 pairs of chromosomes, which is the same as elephants, its closest living relative.
They also looked at which genes were active and found key genes that regulate hair follicle development, and the activity pattern was totally different to that of elephants.
"This discovery highlights the importance of strong research policies that support long-term genetic and conservation studies," Associate Professor Kaur said.
"By learning from the genetic makeup and adaptations of extinct animals, we can develop better approaches to protect endangered species today."