Fossil Chromosomes Discovered: Ancient Woolly Mammoth Skin

In 2018, researchers made an incredible discovery in Siberia: they found fossil chromosomes in a 52,000-year-old piece of woolly mammoth skin. This find is unique because it preserved the mammoth’s genetic material much better than usual.

The cold conditions in Siberia kept the chromosomes’ structure intact, which means scientists can now study the mammoth’s genetic blueprint in great detail. Erez Lieberman Aiden from Baylor College of Medicine said that fossil chromosomes have never been found before, making this discovery very special.

Unlike other ancient DNA samples, these chromosomes kept their 3D shape, which is important for understanding the mammoth’s genetics. This preservation allows scientists to assemble the mammoth’s genome, opening new possibilities in the study of ancient DNA, known as paleogenomics. Olga Dudchenko, also from Baylor, mentioned that this discovery could help study other species too.

A microscope image showed remnants of mammoth nuclei, indicating that ancient chromosomes survived in the sample. Kevin Campbell from the University of Manitoba explained that DNA usually degrades after death, but in freezing conditions like the Arctic, it can stay intact. This finding challenges previous beliefs about DNA degradation.

The researchers compared this preservation to food dehydration, like making beef jerky, which prevents DNA from spreading out and keeps the chromosomes in place. Dudchenko explained that the mammoth’s natural preservation conditions worked similarly, allowing the chromosomes to stay intact for thousands of years.

Even though the DNA wasn’t completely intact, the fragments stayed in order, like finding unbound pages of a book neatly piled together. This rare preservation gives scientists a unique chance to study the genetic material in its original form.

Experiments showed that the DNA was resilient, even under extreme conditions. This discovery revealed that woolly mammoths had 28 chromosome pairs, like modern elephants, and provided insights into their gene activity. These insights could help scientists understand more about mammoth biology and behavior.

While the complete mammoth genome isn’t assembled yet, this discovery is a big step forward. It could also help study other permafrost-preserved species and museum specimens, potentially revolutionizing our understanding of extinct species. The potential for future discoveries is vast and could lead to significant advances in paleogenomics.

Peter Heintzman from Stockholm University said this study is a major advance in paleogenomics, highlighting its potential to reveal new insights into how extinct species evolved and lived.

Re-reported from the article originally published in CNN.