A new study concluded that the ancient humans caused the big mammals’ extinction, thousands of years ago, a tendency that continues nowadays, to some extent, but which could make the cow become the largest mammal on the Earth, in just a few centuries.
The spread of hominids from Africa
The first humans and their ancestors’ migration from the African continent coincided with the disappearance of big mammals of those time, such as the mammoth, the prehistoric smilodon tiger, and the glyptodon.
“There is a very clear pattern of extinction associated with the size of the migration of African hominids,” Felisa Smith, the author of the study, which has been published in the journal Science.
Humans targeted big species for their meat, while smaller animals, such as rodents, have escaped.
In North America, for example, the average mass of big mammals decreased to 7.6 kilograms from 98 kilograms after the arrival of humans.
If this trend continues, “in a few hundred years, the largest mammal on Earth could be the good domestic cow of about 900 pounds,” the team of researchers from the United States noted.
This would entail the big mammals’ extinction, in species such as elephants, giraffes, and hippos. In March, for example, the last northern white rhinoceros male died, in Kenya.
A second research is doubting these conclusions
This second study blames on the conservation efforts claiming to be sufficient to keep away threats facing wildlife such as climate change, deforested habitats, pollution, and the expansion of areas urban.
Thomas Brooks, the chief scientist at the International Conservation Union (IUCN), who was not involved in the recent study in the United States, said that the future of smaller mammals is “grim”.
“Fortunately, I do not think it’s very possible,” he told, referring to the expected disappearance of today’s big mammals. In his opinion, large-scale creatures, such as elephants, are more likely to benefit from protected areas than the smallest.
Felisa Smith replied saying she would like to say that “this will not happen because we love elephants,” but the number of big mammals is declining, and this decline “is the trajectory toward the big mammals’ extinction.”