A team led by scientists from the Chinese Academy of Sciences and China's Northwestern Polytechnical University presents in this week's Nature Ecology & Evolution a genomic analysis of Pseudoliparis swirei — a snailfish species that lives in the Mariana Trench — offering clues about how these vertebrates survive in an environment of darkness, cold, low oxygen levels, and extreme pressure. The researchers sequenced the genomes of several snailfish caught in locations around four miles below the ocean's surface to discover a number of molecular adaptations including ones linked to pressure-tolerant cartilage, loss of visual function and skin color, enhanced cell membrane fluidity and transport protein activity, and increased protein stability. The findings, the authors say, will help further understanding of how species adapt to harsh deep-sea environments.
Also in Nature Ecology & Evolution, investigators from the US and Europe report an analysis of ancient DNA that suggests farming was introduced to England by Neolithic farmers arriving from the European continent along a Mediterranian route. The scientists studied genome-wide data on six Mesolithic individuals and 67 Neolithic individuals who lived in Britain between 8,500 BC and 2,500 BC, finding genetic similarities between British Neolithic and Iberian Neolithic individuals indicating that the British individuals mostly descended from Aegean farmers. They also found little evidence of interbreeding between Mesolithic and incoming Neolithic British individuals, but uncover "overwhelming support for agriculture being introduced to Britain by incoming continental farmers, with small, geographically structured levels of hunter-gatherer ancestry."
Lastly in Nature Ecology & Evolution, investigators from Germany and Japan publish the genomes of two medusozoans — the scyphozoan Aurelia aurita and the cubozoan Morbakka virulenta — illuminating the molecular mechanisms underpinning the jellyfish body plan. They find significant number of genetic differences between the two organisms, as well as evidence that a combination of conserved and novel medusozoa-specific genes are required for the polyp-to-jellyfish transition. Overall, the findings represent "an important comparative resource for understanding medusozoan biology, particularly the developmental and evolutionary aspects of their complex life cycles," the scientists say.