"Mutilation of tree of life": Human activity wiped 71 branches of species from Earth, 35 times faster than expected

Take it from us, reading a research paper can be rough. A distinct lack of flamboyance in the scientific writing might help researchers focus on the experimental results, but it certainly does naught for its importance — especially if you're particularly unversed in the subject.

Once in a while, however, you find language such as "biological annihilation" or the "mutilation of the tree of life" that thoroughly jolts you to your core, helping keep your attention piqued as you gobble the rest of the article up.

Stanford University and the National Autonomous University of Mexico have co-published a study aptly titled "Mutilation of the tree of life via mass extinction of animal genera". With such a strong title, it can be easy to dismiss the paper as clickbait. But the study is anything but.

From the cold peaks of the Himalaya mountains to the tremendous depths of Mariana, there isn't a single habitat untouched, directly or indirectly, by human hands. This vast and encumbering anthropogenic influence has drastically impacted many fragile ecosystems, resulting in what many scientists term the Earth's sixth mass extinction.

However, it turns out we're not just losing animals by the species anymore; it's by the genus now. Examining 34,600 land-dwelling vertebrate animals revealed that we have lost 73 genera (plural of genus) since 1,500 AD — 35 times faster than the extinction rate of the last million years.

Here's the crash course on what these words mean. While species might refer to a specific type of animal, genus refers to the overall family of similar animals. For example, your pet dog might belong to the species 'Canis lupus', it also belongs to the genus 'Canis', which can also include other comparable species such as wolves and jackals.

Basically, the study notes that instead of losing single pages to a human-shaped whirlwind, we've begun to lose entire chapters of genera. And like chapters serve their function within the book, so do these collections of species within their ecology.

When a species dies out, other species of its genus can fill in their shoes within the ecosystem. Soon enough, these cousin species evolved enough to fill the void caused by the species death, helping stabilise the habitat.

However, when an entire genus dies off, it can create a ecological hole so big that it might take tens of millions of years to fill. For example, the extinction of passenger pigeons butterflied into the proliferation of Lyme disease-causing mice, which could eventually devastate human health.

"In the long term, we're putting a big dent in the evolution of life on the planet," remarks study author Gerardo Ceballos. "But also, in this century, what we're doing to the tree of life will cause a lot of suffering for humanity."

Five centuries of toxic human meddling ensured that we lost an additional 71 generas from the face of the planet. Birds suffered the worst among these with 44 genus extinctions, followed by mammals, amphibians and reptiles. This shocking die-off rate would normally have taken 18,000 years to accumulate.

India is no stranger to extinctions either. Being a tropical country, we boast some of the most species-diverse habitats in the world — also meaning we could be riddled in genus-wide holes if we keep harassing ecosystems at the same rate. The study's authors also stress that, for these reasons, we must ramp up conservation efforts in the tropics.

"The size and growth of the human population, the increasing scale of its consumption, and the fact that the consumption is very inequitable are all major parts of the problem," the authors plead, calling for immediate political, economic and social action on this front.

The findings of this study have been published in Proceedings of the National Academy of Sciences and can be accessed here.

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