volcanic eruptions & human bottlenecks

We know, from looking at the amount of genetic variation in the global human population, that it went through a fairly pronounced bottleneck around 70,000 years ago. This has been variously attributed to the founder effect, with only small populations moving out of Africa into Europe & Eurasia, and to the devastating consequences of the […]

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x-rays & age

In the LA Times there’s a story about using X-rays of bones to estimate people’s age. The reporter’s talking about the potential for this technique to obtain fairly accurate ages for those tiny, brilliant, and possibly under-age Chinese gymnasts from the 2008 Olympics. But the underlying anatomical and developmental data have been applied to some equally problematic, but […]

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brain food

Your brain is an energy-hungry organ – even when you’re resting, it can use up to 25% of available energy (chimp brains use about 8%: Gibbons, 2007). In other words, the running costs of a large brain are quite high. And yet humans, with their large brains, take in about the same number of calories […]

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mtDNA & neandertal/sapiens relationships

When I was at high school, mumblety-mumble years ago, the accepted wisdom was that modern humans and Neandertals were sub-species in the same genus: Homo sapiens sapiens and H. sapiens neandertalensis. That changed, to the view that they were probably separate species, with analyses of new fossil finds. More recently, molecular biology techniques have enabled researchers to compare sapiens & […]

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a smelly story

At the moment I’m reading Neil Shubin’s book Your inner fish. It’s a wonderful walk through the evolution of life, taking various aspects of our own biology & tracing their evolutionary history. Over lunch I was reading the chapter on the sense of smell, & some of the ideas there really excited me & I […]

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