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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Ancient Beast was part-sabretooth, part-otter

The extinct carnivore, Kolponomos, looked like a bear, and bit like a sabre-toothed tiger.

A group of carnivores that went extinct around 20 million years ago looked superficially like modern bears, but new research shows their bite was more similar to sabre-toothed cats. Known as Kolponomos, these extinct bears were thought to feed on shelled organisms, like modern otters, but with few fossils to go on, their diet and lifestyle has remained contentious.

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Honeybees treat their mates for STDs

Male honeybees produce antimicrobial chemicals in their semen to protect new queens from a fungal disease.

Sex always comes with the risk of contracting a sexually transmitted disease, so male honeybees have evolved to produce antimicrobial chemicals in their semen. The fungus Nosema apis is a specialised pathogen of honeybees, which can be transmitted to new queens when they mate, but new research shows that male honeybees’ semen has powerful antifungal activity, disrupting the lifecycle of the Nosema spores and reducing their viability.
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Epigenetics Affect How Corals Respond to Climate Change

Genes associated with stress tolerance in corals have fewer epigenetic markers, enabling a rapid response to environmental change. In six species of coral, the team from the University of Washington found DNA methylation, a common epigenetic molecular marker, differed between different genetic regions, and was extremely low in genes relating to stress tolerance. Epigenetics could play a key role in determining how corals cope with climate change.
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Practice Makes Perfect:
Tool-Foraging Dolphins Improve with Age

A group of bottlenose dolphins in Shark Bay, Western Australia, use a clever trick to access prey on the sea floor – they cover their beaks with marine sponges to protect themselves from sharp rocks as they search for food. 30 years after the behaviour was first reported, scientists have now found that individuals improve with practice, peaking just when it matters most.
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Stick Insects Sway to Stay Alive

If you ever owned a pet stick insect as a child, you might have noticed them swaying back and forth at the end of a twig, but until recently, nobody knew what this strange behaviour was for.
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Thanks to Dorothy Floyd for pointing out that we have known anecdotally that this behaviour was likely a form of camouflage for several decades! (see Floyd (1987) Keeping Stick Insects)