Our planet has experienced mass extinction five times. Evolution and natural selection have resulted in the loss of 99.9 percent of species. But this time, one species is way ahead of the natural causes in being the major reason for the extinction of the many species of the planet. It’s, not surprisingly, us the humans. And the chances of life quickly bouncing back seems thin.

According to a new study by a team of biologists focused on finding the impact of humans on biodiversity and how long it will take evolution to bring back the extinct species, it will take 3 to 5 million years to recover the lost lineages of mammals in the next 50 years if the species continues to disappear at the current rate.

The last extinction that wiped out dinosaurs from the face of the earth occurred 66 million years ago. This extinction was named as Cretaceous-Tertiary extinction which resulted in a dramatic reduction in phylogenetic diversity which is eventually filled with new species over time. But the next extinction would be different.

But the current extinction event is quite different from past extinctions which were triggered by sudden and singular events. The current extinction event is caused by humans.

The authors also note that not all mammals are created equal in their phylogenic importance. For instance, there were only four species of saber-toothed tigers and they all went extinct, cutting off an entire branch in the mammalian evolutionary tree. In comparison, the authors note that there are hundreds of species of shrew, meaning the extinction of several of these species does not eliminate the entire evolutionary branch.

The report also noted how the surviving species were always smaller in size. Humans have killed larger mammals and made them go extinct.

The study is a wake-up call for human species to live in coexistence along with the thousands of species out there. The impact human activities have on the environment and climate severely affect other species on the planet. We need to keep the tree of life alive and breathing.