According to a new study carried out by an international team of scientists from Sweden, Switzerland, and the United Kingdom, the human-caused biodiversity decline started much earlier than was previously proposed, and not even by our own species, but by that of some of our ancestors millions of years ago. The study was published in the scientific journal Ecology Letters. 

Soren Faurby, a researcher at Gothenburg University and main author of the study said, “the extinctions that we see in the fossils are often explained as the results of climatic changes but the changes in Africa within the last few million years were relatively minor and our analyses show that climatic changes were not the main cause of the observed extinctions.” Computational biologist and co-author of the study, Daniele Silvestro, added, “our analyses show that the best explanation for the extinction of carnivores in East Africa is instead that they are caused by direct competition for food with our extinct ancestors.”

There were thought to be many of our common ancestors living throughout East Africa for many millions of years. And during this time, multiple extinctions are thought to have taken place. By studying African fossils, researchers can see a big reduction in the number of large carnivores, starting around 4 million years ago. It’s during this time that our ancestors are also thought to have started using a new kind of technology called kleptoparasitism in which to get food.   

Kleptoparasitism is essentially the stealing of recently slaughtered animals from other predators. On the surface, the individual animal goes hungry. But deeper than that, the whole species eventually dies out. “This may be the reason why most large carnivores in Africa have developed strategies to defend their prey,” hypothesizes Faurby. We as humans affect the planet far more today than we ever have. But, as Faurby says, “this does not mean that we previously lived in harmony with nature. Monopolization of resources is a skill we and our ancestors have had for millions of years, but only now are we able to understand and change our behavior and strive for a sustainable future. “