We’d like to see what the creationists can do with this article at PhysOrg: Smarter brains are blood-thirsty brains. No, it’s not about vampires. Here are some excerpts, with bold font added by us:
A University of Adelaide-led project has overturned the theory that the evolution of human intelligence was simply related to the size of the brain — but rather linked more closely to the supply of blood to the brain. The international collaboration between Australia and South Africa showed that the human brain evolved to become not only larger, but more energetically costly and blood thirsty than previously believed.
How did they figure that out? We’re told:
The research team calculated how blood flowing to the brain of human ancestors changed over time, using the size of two holes at the base of the skull that allow arteries to pass to the brain. The findings, published in the Royal Society Open Science journal, allowed the researchers to track the increase in human intelligence across evolutionary time.
This is the paper they’re talking about: Fossil skulls reveal that blood flow rate to the brain increased faster than brain volume during human evolution. The title is a bit more subdued than PhysOrg’s title, or ours. You can read the paper online without a subscription, but we’ll stay with PhysOrg. They say:
“Brain size has increased about 350% over human evolution, but we found that blood flow to the brain increased an amazing 600%,” says project leader Professor Emeritus Roger Seymour, from the University of Adelaide. “We believe this is possibly related to the brain’s need to satisfy increasingly energetic connections between nerve cells that allowed the evolution of complex thinking and learning. To allow our brain to be so intelligent, it must be constantly fed oxygen and nutrients from the blood. The more metabolically active the brain is, the more blood it requires, so the supply arteries are larger. The holes in fossil skulls are accurate gauges of arterial size.”
One last excerpt:
Co-author Dr Edward Snelling, University of the Witwatersrand, says: “Ancient fossil skulls from Africa reveal holes where the arteries supplying the brain passed through. The size of these holes show how blood flow increased from three million-year-old Australopithecus to modern humans. The intensity of brain activity was, before now, believed to have been taken to the grave with our ancestors.”
Creationists, of course, will say that those African fossils are just monkeys, so their skulls reveal nothing about our own divinely created species. Your Curmudgeon, always a gentleman, will refrain from speculating about the blood supply flowing to the creationist brain.
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