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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read the question!

I know I’ve said this before. And your teachers will have said it too. But – read the question! Why am I saying this again? Because I’m marking essays at the moment & I seem to be writing that phrase rather more often than I’d like. When I set a question, whether it’s for a […]

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