Scroll down to know why the ice age animals were driven to extinction
Today, there are more than 10 million species of complex life on this planet. However, as per some biologists, there were more than five billion complex species that ever lived. It means that around 99% of species are not around any more and they are now extinct. To everyone’s dismay, more and more species are driven to extinction every year.
As per many scientists too, the current one is the sixth mass extinction – which is leading to a wide species extinction and undoubtedly, humans are the main cause. Overhunting, overfishing, and human-driven habitat loss are behind it and if this continues, we will soon enter a new phase in Earth's history - "Anthropocene" - wherein by 2100, humans will become the cause of extinction of up to half of the world's current species.
What led to extinction of ice age animals?
Global temperatures are believed to have soared by about 6 degree Celsius. Hence, when Earth was emerging from the last ice age, the extinctions began which would have affected larger animals more because they don’t tend to lose heat as fast as smaller animals. Some think that the climate also swings with time and from very wet to very dry conditions, which leads to exacerbated megafaunal extinctions. Since mammals from the ice age would have likely had thick fur coats, they could not easily adapt to the changing climate.
In case of American and Australian megafaunal extinctions, overhunting is the main culprit.
Apart from climate change and overhunting, the migrating humans or their animals was one of the reasons as well. As per evidence, when humans migrated into the area, they hunted the native fauna and since indigenous animals were not used to hunting tactics, their survival was difficult.
Why did humans end up overhunting 23 species but not the other nine?
During the period of ice age extinctions in North America, the human population was too low to have caused widespread extinctions. More so, the humans did not have the tools available to kill huge mammals. Surprisingly, out of the 32 genera of megafaunal mammals during the last ice age, nine survived – and still there is no clear reason for it.
Can we think that the extinctions were caused by both a changing climate and overhunting by humans? Since it was the case in the late Pleistocene megafaunal extinctions in South East Asia, that is also a possibility.
Hence, the conclusion lies in the fact that combined factors were able to drive multiple groups of species to global extinction.
