Sapiens: Guilty as Charged

In the past, humans stayed within Afro-Eurasia, never venturing outwards towards Australia, America, or any other remote islands. Some called this the 'Outer World'. However, 45,000 years ago, humans felt inclined to travel to the 'Outer World', resulting in animal extinctions across Australia and America, and a change in the food chain as Homo Sapiens became the most deadliest species during that time. There are any theories as to why there were extinctions in those regions, but human migration to Australia and America was believed to be the main reason.

In Australia, large animals dominated the food chain, such as lizards and snakes 7 feet long, earthbound birds twice the size as ostriches, 450 pound kangaroos, etc., but when humans arrived to Australia, the Australian ecosystem became especially disrupted. When humans came to Australia, they were experts in fire agriculture, burning great amounts of forests to create grasslands, therefore producing a better hunting ground for humans and a threat to animals. Homo Sapiens would also kill these big animals for consumption; however, because the animals' species wouldn't be able to keep up with the humans and reproduce enough offspring to replace the damage done by humans, the species itself would die off. Furthermore, although many also think climate change contributed to the extinction of the enormous animals, the weather was always changing, making animals adaptable to their environment and learning ways on how to survive. In addition, when a drastic change in the climate takes place, both the land and sea animals would be affected, but 45,000 years ago, studies showed that sea animals remained unaffected, whereas land animals continued to die and go extinct. Furthering anthropologists' point, more than 90 percent of Australia's big animals--otherwise called the megafauna--vanished at the same time humans arrived to Australia, making the disappearances of Australia's megafauna seem more than just a coincidence. Climate may have had an effect on the extinction of animals, but it played a small role compared to humans. With both the threat of the climate and humans, the large animals were unable to fight off both. Humans, in addition to Australia, also migrated to America between 1200 to 900 B.C. because of their great ability to hunt and make clothes. Because of this, they were able to move to colder regions, opening new opportunities of land, food, ect. for them. Homo Sapiens were very impactful on the food chain for North America lost thirty-four out of its forty-seven species of large animals, while in South America, fifty out of its sixty species were gone.

In both Australia and America, the human arrival declined the large animal population dating far back to before people even realize.