DNA detectives in Antarctica: probing 6,000 years of penguin poo for clues to the past

Jamie Wood Jamie Wood, University of Adelaide and Theresa Cole, University of AdelaideStudies of ancient DNA have tended to focus on frozen land in the northern hemisphere, where woolly mammoths and bison roamed. Meanwhile, Antarctica has received relatively little attention. We set out to change that. The most suitable sediments are exposed near the coast of the icy continent, where penguins like to breed. Their poo is a rich source of DNA, providing information about the health of the population as well as what penguins have been eating. Our new research opens a window on the past of Adélie penguins in Antarctica, going back 6,000 years. It also offers a surprise glimpse into the shrinking world of southern elephant seals over the past 1,000 years. Understanding how these species coped with climate change in the past can help us prepare for the future. Wildlife in Antarctica faces multiple emerging threats and will likely need support to cope with the many challenges ahead. A unique marine ecosystem Adélie penguins are particularly sensitive to changes in their environment. This makes them what we call a “sentinel species”, providing an early warning of imbalance or dysfunction in the coastal ecosystem. Their poo also provides a record of how they responded to changes in the past. In our new research, we excavated...
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World’s Largest Genome Discovered in a Tiny Fern: ‘Breaks all records’

A group of small fork ferns – credit Pol Fernandez, released via iScienceOn the island of New Caledonia, a simple, unassuming species of fern has been identified as having the longest genome of any living organism known.It is 50 times longer than a human’s, 7% longer than the previous world record-holding species for longest genome, and 20% longer than the record-holding animal.Compared to 23 pairs of chromosomes in every human cell, the tiny fern contains 416—and if unraveled, would climb higher than Big Ben in London’s Westminster.Questions abound, as does admiration for the majesty and mysteries of biological life.“Compared to other organisms, plants are incredibly diverse when viewed at the DNA level, and that should make us pause to think about their intrinsic value in the wider picture of global biodiversity,” said Dr. Ilia Leitch, Senior Research Leader at the Royal Botanical Gardens, Kew.“This discovery also raises many new and exciting questions about the upper limits of what is biologically possible, and we hope to solve these mysteries one day.”Tmesipteris oblanceolata is a species of New Caledonian fork fern that grows on the ground or out of rotting tree trunks. A team from Kew and the Institut Botànic de Barcelona traveled to New Caledoina’s largest island of Grand Terre to collect this species for study.20,000 species...
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