High on Speciation: latitudes and species diversity

It seems like a no-brainer: To find out where most new species arise, see where most of them live. Take the tropics, home of more than half the known organisms on the planet. For nearly a century, researchers have assumed that new species are constantly popping up here, while speciation is far more stagnant at Earth's relatively deserted poles. But a new study claims the opposite: Species evolve much more readily at higher latitudes. It's just that the new arrivals die off so fast that most of them never get counted.
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