The sixth mass extinction of global biodiversity is already in progress

Shells of land snails from Rurutu (Austral Islands, French Polynesia) – recently extinct before they were collected and scientifically described. Credit: O. Gargominy, A. Sartori

Five times the history of life on Earth has been marked by mass biodiversity extinction events caused by extreme natural phenomena. Today, many experts warn that the sixth mass extinction crisis is underway, this time being caused entirely by human activities.

A comprehensive assessment of the evidence for this ongoing extinction event was recently published in the journal Biological Reviews by biologists from the University of Hawaii at Manoa and the National Museum of Natural History in Paris, France.

Said Robert Coy, lead author of the study and research professor at the UH Mānoa Pacific Biosciences Research Center in the School of Earth and Ocean Science and Technology (SOEST). “This denial is based on a highly biased assessment of the crisis that focuses on mammals and birds and ignores invertebrates, which of course make up the vast majority of biodiversity.”

Extrapolating from estimates obtained from land snails and slugs, Coe and co-authors estimated that since 1500, Earth could have already lost between 7.5 and 13% of its two million known species—a staggering 150,000–3 260,000 species.

“The inclusion of invertebrates was a key factor in confirming that we were indeed witnessing the beginning of the sixth mass extinction in Earth’s history,” Coy said.

An example of the habitat of a ground snail

The native Hawaiian snail’s habitat is in Pu’u Kukui, Maui. Credit: Robert Coy

However, the situation is not the same everywhere. Although marine species face significant threats, there is no evidence that the crisis is affecting the oceans as much as land. On land, island types, such as those on the Hawaiian Islands, are affected more than continental ones. The rate of plant extinction appears to be lower than the rate of wild animal extinction.

Unfortunately, along with denying science is taking a foothold in modern society on a range of issues, the new study suggests that some people also deny that the Sixth Extinction began. In addition, others accept it as a new and natural evolutionary path, because humans are just another species that plays its natural role in Earth’s history. Some even argue that biodiversity should only be manipulated for the benefit of humanity – but who determines it?

“Humans are the only species capable of manipulating the biosphere on a large scale,” Coy asserted. “we Not Just another species that evolves in the face of outside influences. In turn, we are the only species with a conscious choice regarding our future and the future of Earth’s biodiversity.”

To combat the crisis, several conservation initiatives for some charismatic animals have succeeded. But these initiatives cannot target all species, nor can they reverse the general trend of species extinction. However, it is imperative that these efforts continue, continue to inculcate the wonders of nature, and document biodiversity before it decisively disappears.

“Despite the rhetoric about the seriousness of the crisis, and despite the fact that remedial solutions are in place and brought to the attention of decision-makers, it is clear that the political will is missing,” Cui said. “Denying the crisis, accepting it without reacting, or even encouraging it negates humanity’s shared responsibility and sets the stage for the Earth to continue its sad path toward the sixth mass extinction.”

Reference: “The Sixth Mass Extinction: Fact, Fiction, or Conjecture?” Written by Robert H. Coy, Philip Bouchet and Benoit Fontaine January 10 2022And Biological Reviews.
DOI: 10.1111 / br.12816

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