Given the short half-life of DNA, we may never have a Jurassic Park – but could we one day boast of an Ice Age Garden?
Scientists have brought back to life a collection of roughly 400-year-old frozen plants recovered from melting glaciers in the Canadian Arctic. The feat, described in Proceedings of the National Academy of Sciences, shows that certain plants might be much tougher than previously thought, able to regenerate after centuries under ice.
"Their structural preservation is exceptional," the study authors wrote.
The plants were dug out from Sverdrup Pass, where the Teardrop Glacier has been melting at faster and faster rates – from 3.2 meters per year between 2004 and 2007, up to 4.1 meters from 2007 to 2009. Both of these are roughly double earlier calculated rates from just a few decades ago. The melt has been exposing long-frozen Arctic plants, whose blackened and discolored remains were long considered dead.
But researchers at the University of Alberta in Edmonton, Canada, who were collecting these dried-out plants for study began to notice something strange: Some of their samples were sprouting new growth – little green branches and stem buds – straight out of the supposedly dead material.
At first, this seemed unlikely – after all, these plants had been entombed since the Little Ice Age, a frigid 300-year period between AD 1550 and 1850. So the researchers dug up a sample of various bryophytes – hardy plants, including mosses, that lack the vascular tissue that other plants use to transport fluids around the body. Based on radiocarbon dating, their samples ranged in age from roughly 400 to 600 years old.
This is not the first time apparently dead plants have been brought back to life – Russian scientists recently revived a 30,000-year-old Ice Age plant known as Silene stenophylla and even coaxed it into flowering.
But that effort was a complicated process, which involved extracting placental tissue out of seeds, cloning it, and then growing it on a special bed of nutrients to stimulate the growth of shoots, the authors pointed out. For the current finding, the researchers essentially ground up stems of leaves of their hardy plants and sowed them into potting soil or another growth medium.
"Our contribution demonstrates that bryophytes buried in ice 400 years ago can remain dormant and provide an unrecognized pathway for recolonization of deglaciated terrains (recent and ancient)," the authors wrote.