(ORDO NEWS) — Nature is in crisis and it’s only getting worse. As species are disappearing at a rate not seen in 10 million years, more than 1 million species are currently on the brink of extinction.
Humans are causing this extinction crisis because of activities that take over animal habitats, polluting nature and contributing to global warming, scientists say.
A new global agreement to protect nature, agreed on Dec. 19, could help save animals, and scientists are urging countries around the world to ensure the agreement’s success.
When an animal species disappears, so does a whole set of characteristics genes, behaviors, activities, and interactions with other plants and animals that may have taken thousands or millions even billions of years to evolve.
Any role that this species played in the ecosystem is also being lost, whether it was pollinating certain plants, mixing nutrients in the soil, fertilizing forests, or controlling other animal populations.
If this function is critical to the health of the ecosystem, the extinction of animals could lead to landscape transformation.
If humanity loses too many species, the consequences could be catastrophic and lead to the collapse of the entire system.
Hundreds of unique animals have disappeared around the world over the past five centuries, such as the flightless Dodo bird killed on the island of Mauritius in the late 1600s.
In many cases, humans are to blame – first because of fishing or hunting, as was the case with the South African subspecies of quagga zebra, which was hunted until the late 19th century, and more recently because of activities that pollute, destroy or take over wildlife. habitat.
Before a species goes extinct, it can already be considered “functionally extinct” – with not enough individuals to ensure the survival of the species.
More recent extinctions have allowed humans to interact with the last known individuals of some species, known as “endlings”. When they leave, that is the end of these evolutionary lines.
“Toughie” was the last known specimen of Rabb’s Fringe-Limbed tree frog. All but a few dozen of its species have been destroyed by the chytrid fungus in the wild in Panama.
The story of the passenger pigeon “Martha” is a cautionary tale for conservation: there were still millions of passenger pigeons in the 1850s, but they were eventually extirpated as conservation measures were taken only after the species had passed the point of no return.
The last individual died in 1914 at the Cincinnati Zoo.
“Lonesome George”, found in 1971, was Ecuador’s last tortoise on Pinta Island. Since the 17th century, about 200,000 individuals have been exterminated for their meat.
They later struggled to compete for food after goats were introduced to the island in the 1950s. Scientists tried to save the species through captive breeding before the last turtle died in 2012.
There are some species that may soon develop into their own endlings. The world’s smallest porpoise, the endangered Mexican vaquita, has dwindled to 18 in the wild as populations were devastated by fishing nets.
A subspecies of the northern white rhinoceros, the second largest land mammal after elephants, has no hope of surviving the species after the death of its last male in 2018. Only the female and her daughter remained.
Scientists say these endling stories matter precisely because so many extinctions go unnoticed. Unlike endlings, most species simply disappear into the wild without people noticing.
Scientists have counted 881 animal species that have gone extinct since about 1500, dating back to the first records held by the International Union for the Conservation of Nature (IUCN), the global scientific regulator for the state of nature and wildlife.
However, this is an extremely conservative estimate of species extinction over the past five centuries, as it only represents cases that have been established with a high degree of certainty. If we include animal species that scientists believe may be extinct, this number rises to 1,473.
The number of recent recorded sightings has been increasing over time, especially since the start of the Industrial Revolution in the mid-19th century.
This shows that animals are increasingly endangered, but also that our knowledge of nature is improving as we study more and more species.
Some disappearances have caused public outcry, such as the announcement in 2016 of the disappearance of a tiny bat species from Christmas Island, last seen in 2009.
It was the first recorded extinction of a mammal in Australia in 50 years.
The loss of hundreds of species in 500 or so years may seem insignificant when millions of other species still live on the planet.
But the rate at which species are now disappearing is unprecedented in the last 10 million years.
When the rate of extinction jumps so high that more than 75% of the world’s species go extinct within a relatively short period of time, less than 2 million years, it is considered a mass extinction event.
This has happened five times in the last half a billion years, as we know from studying the Earth‘s fossil record, as layers upon layers of sediment buried animal remains over time.
When a layer with a large and varied number of animals is discovered, scientists see that a mass extinction has occurred. Scientists warn that we have entered the sixth mass extinction.
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