What caused the Pleistocene Mass Extinction?

[GuateGojira]

Some time ago, in a documentary, it was mentioned that another possibility for the extinction of the megafauna in America, was caused INDIRECTLY by the humans.

The guy in the program (I forgot the name) stated that it was possible that the new humans arriving to America carried a series of diseases that native animals were unable to survive. The animals in the old world where already used to this and where immune, but all those in the other side were not. The virus spread from herbivores to carnivores and in that form they died.

The problem with this is that why it did not affected the "smaller" animals, and the medium size carnivores. Check that although the megaherbivores over 1,000 kg died in North America, those of less than 900 kg survived very well. The American moose is a modern giant with a great population and the bison (that also can reach up to 1,000 in exceptional cases) lived in groups of millions of animals. Wolves, pumas and jaguars survived very well and the bears were very common in all the north, as down as Mexico. This only changed when the Europeans began they holocaust of animals and the killings of the native and TRUE Americans (USA natives, Aztecs, Mayans, Incas, etc....).

North America conserved its great ecosystem, only the large mammoths, mastodons, giant sloths, giant vultures, giant bears and the great cats over 150 kg, disappeared; all the other animals survived very well and flourished. In central and south America, it was a different story. All the animals over 50 kg, at the exception of the tapir and the jaguar, simply died, no more giants at all!!!

Definitely, I don't believe in the disease case, but a mix of human arrival and the climate could be the real reason. I remember another TV program when it was mentioned that the first USA natives hunted the buffalo in a very stupid way: They attacked the full group of animals and direct it to a cliff and killed the entire group. They wasted tons of meat in this form. Modern natives (still way before the arrival of the Europeans), were more advanced in they hunt form and they religious beliefs, so they only hunted what they need it and the buffalo population was very well. Probably, the first humans were in fact, great killers and wasters, and the native animals, been unable to recognize the humans as menace (they evolved for millions of years without them), simply don't defended in the same way that the old world beasts.

This are only hypothesis, but somehow, based in real history and fact, that can help us to found a plausible explanation.


Interesting as it is, did you know that all the pumas from the north of America are descendents from a group of originated from South America? What happen with the primitive population of the north? Reply