Tibetans evolved to cope with UV

Study identifies seven new loci associated with high-altitude living

Tibetan populations have evolved at least nine specific genetic variants to help them survive the extreme conditions of the Tibetan Plateau. Living permanently at over 4,000 m above sea level, these populations have been coping for millennia with 40% less oxygen and 30% stronger UV radiation, as well as exposure and limited food.

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Geological uplift creates mountain biodiversity hotspots

Mountains tend to have more species than valleys, and new research provides support for the theory that mountain formation itself might be responsible.

Yaowu Ying and Richard Ree from The Field Museum in Chicago compared regional rates of plant colonisation and speciation in the Qinghai-Tibetan plateau, a high-altitude biodiversity hotspot. Within the QTP, the Hengduan mountain region is the most biodiverse, harbouring an astonishing 12,000 species in just 500,000 km2. The authors used published datasets to compare the spread of over 4,500 plant species across Hengduan, the Central Asian Mountains and the Himalayas.

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The first skeletons evolved repeatedly in chalky seas

The first skeletons evolved multiple times independently because of unusually chalky seas, later becoming essential for survival even when chalk became scarce.

Calcium-based skeletons appeared suddenly in the fossil record around 550 million years ago, fundamentally changing the global carbon cycle and introducing a wealth of new predatory strategies to the sea.

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Cholesterol and fats prime immune cells to clog arteries

A fatty diet could change your genetic make-up, priming the immune system and causing clogged arteries.

Epigenetic changes – which often involve adding methyl to particular DNA sequences in a process known as DNA Methylation – can alter gene expression in response to environmental stimuli. The field of epigenetics has excited biologists because it allows animals to adapt their genetics to fit the environment, while also passing some of that experience on to the next generation.

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Habitat Disturbance leaves a genetic legacy

Habitat disturbance, be that logging, agriculture, or roads and infrastructure, can be hugely damaging to biodiversity. But even after the visible wounds have healed, the genetic scars of past disturbance remain in the genome, according to results from a two-decade-long study of shrubs in Spain.

The effects of habitat disturbance on plants can be seen in the genomes of the next generation, a new study reports for the first time. The team compared the genetic and epigenetic profiles of shrubs (Lavandula latifolia) that had been experimentally disturbed 20 years previously, with those left undisturbed for more than 50 years.

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The costs of a big brain outweigh the benefits

Brains rather than braun may have guided our ancestors out of Africa, but new research suggests primates’ big brains are no longer the assets they once were.

A study published in the journal Evolution reports that larger brains are directly related to an increased risk of extinction in modern primates. Researchers led by Alejandro Gonzalez-Voyer at Doñana Biological Station in Spain, compared published data on 474 species of mammal, with their IUCN Redlist categorisations, to find out how different biological traits influence extinction risk. The team found that larger brains tend to be associated with a longer gestation period, longer weaning period and smaller litter sizes, all of which indirectly increase extinction risk.

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Ancient fossil arachnid reveals the origins of spiders

A new fossil discovered in France promises to shed light on the murky evolutionary history of spiders. The rare three-dimensional fossil of the new species shows that it is nearly, but not quite, a spider, lacking the key silk-spinning adaptation that defines spiders. This 300-million-year-old arachnid is our closest view yet of the ancestor to all spiders.
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