Have you ever wondered why we have to go all the way to Africa to see a safari? For Africa is the land of 13000 lb elephants and 18 foot tall giraffes.
But what many do not realize is that 40,000 years ago, the whole World looked like an African safari. North America and Eurasia were home to Pachystruthio dmanisensis, a flightless bird that stood 11.5 feet tall and weighed nearly a 1000 lbs.
North America was also home to the short-faced bear which stood up to 14 feet tall, weighed about 1700 lbs, and could run up to 40 miles per hour. And of course who could forget the 13000 lb mammoth, which lived on every continent except Australia.
Scientists call these giant animals “megafauna” (mega = big, and fauna = animals). We still have megafauna in the world, but there used to be a whole lot more of it. In fact, it appears that having a large number of large-bodied animals in an ecosystem is actually the normal state for our planet, at least for the geologic era we are living in today, the Cenozoic (or “Age of Mammals”) . But sometime in the past 50,000 years (very recent geologically), everywhere except for Africa, most of those large animals became extinct. And we still aren’t sure why!
Some scientists think megafauna survived in Africa because humans evolved there so large animals had more time to adapt to us. However members of the genus Homo have been living outside Africa for 2 million years, so Eurasian megafauna had time to adapt to us too. Another theory is that megafauna were killed off by the extreme climate changes that megafauna endured outside Africa.
But in asking why megafauna went extinct everywhere except Africa, politically correct scientists are forced to ignore the elephant in the room (pun intended): HBD. If Arthur Jensen was correct about the black-white IQ gap being genetic, perhaps Africans simply hadn’t evolved the intelligence to hunt large game.
But that can’t be the whole story. If racial differences in IQ evolved because we needed more intelligence to survive the non-tropics, how were Australian aboriginals (who retain a tropical phenotype) able to kill off 100% of their giant mammals? Migrating from Africa to Australia means their ancestors must have spent some time in the non-tropical ice age Middle East. Was this enough time for them to evolve the intelligence to hunt big game or was the big game in Australia simply easier to hunt because it had not had the time to evolve ways to avoid humans?
If cold climate selected humans were especially evolved for hunting big game, and if the big game on continents where humans had never been were especially bad at evading human predators, then these two factors predict the biggest megafauna massacre of all should have occurred in the Americas where both conditions were met: cold adapted hunters (humans entered the Americas from Siberia) entering a continent where humans had never been.
And indeed that seems to be the case. Paleo-biologist Rebecca Terry at Oregon State University says “pretty advanced weaponry was definitely present, and the extinctions in the New World in North America and South America were really extreme as a result.”
11,000 years ago (shortly after modern humans entered the New World), the average weight of a non-human mammal in North America was about 200 pounds compared to only 15 pounds today.