Lice evolved with birds and mammals

Parasites are thought to diversify with their host species, but the theory has rarely been tested. Kevin Johnson at the University of Illinois and his colleagues sequenced the genomes of 46 species of lice that parasitise birds or mammals, and two non-parasitic bark lice, and constructed an evolutionary tree. They estimated that parasitic lice first emerged between 90 and 100 million years ago, but didn’t begin to diversify until 66 million years ago – around the time of the dinosaurs’ extinction.

Continue reading

Ants immunise their young

As I’ve mentioned before, living in a large densely-packed social group, like a city or an ant colony, comes with some drawbacks – perhaps worst of which is the risk of catching a contagious diseases. Earlier this year I wrote about research showing that raider ants treat injured workers’ wounds, helping them to heal. Now, a new study shows that the queen can pass on resistance to diseases she’s encountered, arming her workers against pathogens.

Continue reading

The Ant Doctor Will See you Now

I’ve spent more time than most observing ants, and I’ve come to find them ‘cute’ – something few other people understand, and that is often hard to convey. So it’s nice to find a paper that offers the opportunity to give people a glimpse into the cuteness I see in ant behaviour.

Ants clean the wounds of injured nest mates, often saving their lives and keeping infection out of the colony.

Continue reading

What are the effects of yoga and meditation on the brain?

Question:

What are the effects of yoga and meditation on the brain? (Asked by @leximills)

Answer:

Yoga and meditation have effects on physiology, brain chemistry, and cognitive processes; these vary depending on the exact type of practise being performed and how long a person has practised it for. Studies of brain activity confirm that meditation can achieve a state of calm, thoughtless awareness, by suppressing brain regions involved in external attention and irrelevant information, and activating brain regions involved in internalised attention and positive emotions. Meditation is thought to activate the parasympathetic-limbic pathways, reducing heart rate, lowering blood pressure and slowing breathing. Meditation practises can fundamentally change the shape, structure and function of the brain – reinforcing neural networks, developing particular brain regions and influencing the production of key neurotransmitters and hormones in the brain related to attention, self-awareness and emotional control. Yoga has far-reaching effects on the body, reducing inflammation, boosting mood and making long-term practitioners feel more awake. It may even speed up learning in childhood and slow the natural cognitive declines that come with ageing. However, our understanding of the effects of meditative practises on the brain and body is still in its infancy – much more work remains (especially large-scale, carefully controlled trials).

Continue reading

Why Are We So Obsessed With Ivory?

A guest post for Curious Meerkat by Emily Folk.

Have you ever considered a world without elephants? This is a world we’re heading toward with the profound level of poaching that has occurred. As a result of almost institutionalized poaching over many decades, we have decimated the population of wild African elephants to between 400,000 and 600,000 individuals.

Continue reading