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BIOGEOGRAPHY: Genetic mutation may have allowed early humans to migrate throughout Africa "Modern humans arose about 180,0 00 years ago. And for almost 100,000 of those years, we stagnated around bodies of water in Central Africa. Our ancestors developed a mutation that allowed them to convert medium chain plant-based Polyunsaturated Fatty Acids (PUFAs) into long chain Brain PUFAs that were vital for brain growth and function."
NATURAL SELECTION: "A recent study found that the more aggressive devils were "super-spreaders" for DFTD. More aggressive devils do not get bitten so often, but they end up biting the tumours of infected devils. Because of this selection pressure, less aggressive devils may stand a better chance of survival."
HOMOLOGOUS STRUCTURES-suppose EVOLUTION is to be compared to a Mountain with different peaks, and the higher we go on the mountain the greater is the complexity. Suppose you're already halfway up there, and suddenly realise while standing on the vantage point that there's a a better route! But you can't climb all the way down and start afresh, because that's just not evolution, as it has no foresight, and you'll have to make do with whatever you've got. "
NATURAL SELECTION "Many organisms have exoskeletons, including grasshoppers and crabs. Over the course of evolution, exoskeletons have proved themselves time and time again - for instance, insects have been around many millions of years and are found in almost every ecosystem on Earth. But how do exoskeletons compare to our bones?"