Permafrost usually hits the news as a hazard; a planetary risk. When this ice-rich ground thaws, it damages roads and building foundations. It drains lakes and tips trees into drunken forests. It releases greenhouse gases that have been locked in carbon-rich soils for thousands of years, amplifying warming, driving further thaw.<\/p>\n
These are serious concerns, and we spend a good deal of time studying their causes. But another consequence of permafrost thaw receives far less attention: As the climate warms, we are losing our frozen heritage.<\/p>\n
Permafrost contains the most exceptional archive of the distant past on the planet, a record of ancient life preserved in a way that exists almost nowhere else on Earth.<\/p>\n
A recent study we led, published in Nature Communications, recovered DNA from Arctic ground squirrel droppings preserved in permafrost in Klondike, Yukon. In these pellets, we found plants the squirrels had eaten, parasites they carried and even traces of the larger animals \u2014 mammoths, horses and bison \u2014 that shared their grassland.<\/p>\n
A single dropping held a detailed portrait of a vanished ecosystem, spanning an extraordinary depth of time \u2014 from around 14,000 to 700,000 years ago.<\/p>\n
Fossils in the \u2018muck\u2019<\/p>\n
In the Klondike region of central Yukon, within the traditional territories of the Tr\u2019ond\u00ebk Hwech\u2019in and the First Nation of Na-Cho Nyak Dun, placer gold miners commonly use high-pressure water to strip away frozen silt and organic material to reach the gold-bearing gravels beneath.<\/p>\n
As the permafrost thaws, it gives up what it\u2019s held for tens of thousands of years: wedges of ground ice; mats of grass roots still woven together; the nest of an Arctic ground squirrel with the animal\u2019s bones curled inside. Every so often, we find the mummified carcass of an ancient wolf pup or the blue-stained glint of a mammoth tusk or a bison skull.<\/p>\n
Miners call this frozen overburden \u201cmuck.\u201d Scientists refer to it as Yedoma \u2014 part of an extensive complex of fine-grained frozen sediment stretching from Yukon across Alaska and the Bering land bridge into Siberia.<\/p>\n
It is one of the richest paleontological and paleo-environmental archives in the world \u2014 and we are only beginning to grasp how much it holds.<\/p>\n
A molecular archive of life<\/p>\n
For most of its history, palaeontology was a hands\u2013on science: a fossil was something you could pick up \u2014 a bone, a tooth, a tusk.<\/p>\n
Over the past decade, that\u2019s changed. Today we examine these deposits at the molecular level. From a teaspoon of frozen soil or the droppings of long-dead animals, we can recover billions of fragments of ancient DNA directly.<\/p>\n
Permafrost preserves not just bone but the fragile, molecular archive of life \u2014 DNA, RNA, proteins, a genetic record of entire communities \u2014 under conditions of cold, darkness and low oxygen that stop the decay that would otherwise erase this material.<\/p>\n
The DNA and proteins are heavily fragmented, but new sequencing technologies and enrichment methods now allow us to reconstruct full genomes and whole communities of ancient organisms from these scattered pieces \u2014 a feat impossible even a few years ago and one that is advancing quickly.<\/p>\n
Discovery of antibiotic-resistant genes<\/p>\n
Ecosystems are only one part of what is held there. Years ago, some of us were part of a team, led by researchers Hendrik Poinar and Gerry Wright at McMaster University, that searched this same ground for antibiotic-resistant genes.<\/p>\n
In 30,000-year-old permafrost, we found a diverse set, including genes associated with resistance to drugs such as vancomycin, with the ancient versions functioning much like those in hospitals today.<\/p>\n
That work showed antibiotic resistance is far older than the clinical use of antibiotics. It also hinted that this frozen ground is a vast, almost entirely unread catalogue of microbial chemistry \u2014 one that may yet inform how we counter drug resistance or yield useful new enzymes.<\/p>\n
Thaw is accelerating as ground warms across the North. As permafrost temperatures climb, microbial activity increases and more unfrozen water becomes available, allowing organic material to begin decomposing even before complete thaw. Material sealed away for thousands of years meets oxygen, free water and microbes, and the record fragments.<\/p>\n
Archives of frozen sediment<\/p>\n
Practically, this means we need to be collecting and preserving far more of this material than we do now \u2014 building archives of frozen sediment and the molecules within them while they can still be read.<\/p>\n
We have made efforts toward this goal in the Permafrost Archives Laboratory at the University of Alberta, one of the few facilities of its kind in the world, but it remains a small collection against a vast Arctic.<\/p>\n
The science to interpret these archives is advancing quickly but the deposits themselves are degrading, particularly in areas of warm permafrost such as central Yukon.<\/p>\n
The only real solution to permafrost thaw is to reduce greenhouse gas emissions and slow the warming of the North. In the absence of that, the least we can do is preserve what we can of this archive \u2014 in cold storage and in careful study \u2014 before significant portions are degraded beyond recovery.<\/p>\n
The invisible DNA archives of a lost world remain buried in these frozen soils. If those records thaw, the beauty and complexity of life that shifted and adapted to the great ice ages of the past, with lessons for our warming world, will be lost.<\/p>\n
\u2014By Duane Froese, professor, Department of Earth and Atmospheric Sciences, University of Alberta; Hendrik Poinar, professor of anthropology and biochemistry and the Micheal G. DeGroote Chair in Genetic Anthropology, McMaster University; Scott L. Cocker, postdoctoral research fellow, Center for Paleogenetics, Stockholm University; and Tyler J. Murchie, scientist, Ancient DNA Lab (biodiversity genomics division) at the Hakai Institute and adjunct assistant professor, anthropology, McMaster University. This article was originally published on The Conversation, an independent and nonprofit source of news, analysis and commentary from academic experts. Disclosure information is available on the original site.<\/p>\n","protected":false},"excerpt":{"rendered":"Permafrost usually hits the news as a hazard; a planetary risk. When this ice-rich ground thaws, it damages…\n","protected":false},"author":2,"featured_media":821493,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[49,48,66],"class_list":["post-821492","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ca","tag-canada","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/821492","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=821492"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/821492\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/821493"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=821492"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=821492"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=821492"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}