Yukon Bison Bone Discovery In Permafrost Sheds Light On Animal Adaptation To Climate Change
A recent discovery at a goldmine in the Yukon may help scientists better understand how animals have adapted to climate change in the past.
A team of scientists, led by researchers from the University of Adelaide, has found a set of roughly 30,000-year-old bison bones in the Canadian permafrost and analyzed their preserved DNA in a "world-first study," according to a press release from the university.
Their study, which was recently published in the journal PLoS ONE, examined the DNA in the bison bones for "epigenetic" changes. According to the University of Adelaide, these are "genetic modifications that turn genes on and off, without altering the DNA sequence itself."
According to The Vancouver Sun, scientists looked at the genetic material from modern cattle and "a 30-year-old mummified cow from New Zealand" alongside the ancient bison bones.
The research team tested the bison DNA for signs of an epigenetic change known as "DNA methylation." They found that not only did this change occur in the ancient bison, but "most of the methylations they found were in exactly the same spots as methylations in the same genes of modern cattle," reports NewScientist.
They concluded that these epigenetic changes occurred among steppe bison when other Arctic and sub-Arctic animals, like woolly mammoths, were dying out during the Pleistocene era.
Their results show that these "changes can occur rapidly between generations," rather than over a traditional evolutionary time scale, according to the University of Adelaide press release. Alan Cooper, the study's leader and director of the Australian Centre for Ancient DNA, said:
Epigenetics is challenging some of our standard views of evolutionary adaptation, and the way we think about how animals use and inherit their DNA. In theory, such systems would be invaluable for a wide range of rapid evolutionary adaptation but it has not been possible to measure how or whether they are used in nature, or over evolutionary timescales.
Cooper and his team's findings -- that ecological stress can contribute to genetic change on a more rapid scale than previously thought -- follow other recent genetic research. HuffPost blogger James Shapiro recently wrote, "As I argue in my June 2011 book, molecular science reveals built-in cell systems for restructuring genomes in times of stress and challenge."