The sixth mass extinction caused by humans

About 30, species go extinct annually. There is little doubt left in the minds of professional biologists that Earth is currently faced with a mounting loss of species that threatens to rival the five great mass extinctions of the geological past.

The sixth mass extinction caused by humans

Humans have killed off at least animal species, including tortoises and dodos on the islands of Mauritius. But imported tortoises from the Seychelles, like this one, may be able to fill that loss. The sixth mass extinction may now be beginning—and the apocalypse this time is us.

During the last several centuries we have burned through eons worth of fossilized sunshine, changing the climate for our fellow species.

Before we even achieved civilization, we had already helped hunt the biggest, fiercest animals—woolly mammoths, giant kangaroos and giant sloths—to extinction.

Biologists and paleoecologists estimate that humans have driven roughly 1, species extinct in ouryears on the planet. Since we have killed off at least types of animalsincluding the passenger pigeonthe Tasmanian tiger and, most recently, the baijia freshwater dolphin in China.

Another 20, or more species are now threatened with extinction according to the International Union for the Conservation of Naturewhich keeps a list of all the known endangered plants and animals on the planet. The population of any given animal among the five million or so species on the planet is, on average, 28 percent smaller, thanks to humans.

And as many as one third of all animals are either threatened or endangered, a new study in Science finds. But according to that new study in Science, the total number of such invertebrates fell by half over the past 35 years while the human population doubled.

That makes this the fastest extinction event on record, even if it is not yet a mass die-off.

The sixth mass extinction caused by humans

The biggest, fiercest animals still left on the planet—elephants, tigers, whales, among others—are most at risk. And we humans have shown no inclination to stop the activities —overexploitation for food, habitat destruction and others—that drive extinction.

In the past few decades humans brought the black-footed ferret back from just seven individuals; vaccinated and hand-reared condors to relative abundance; and battled to preserve and restore populations of hellbender salamanders, to name just a few in just North America alone.

Three Mile Island

According to another new analysis in Science, people have physically moved species of plants and animals to protect them from extinction. For such assisted migration efforts to succeed, careful attention must be paid both to genetics and habitat.

There is no point in bringing back the baiji, for example, if the Yangtze River remains polluted and overfished. But conservation efforts can work.

Fishes can rebound when fishing pressure is removed, just as Maine haddock and Washington State coho salmon both have. The reforesting of the U.

- The Washington Post

And in what might prove an enduring lesson in conservation, paleoecologists have shown that 20 out of 21 large mammals in India —from leopards to muntjac deer—have survived there for the pastyears alongside one of the largest human populations on the planet. To avoid the sixth mass extinction we will probably have to employ more aggressive conservation, such as moving species to help them cope with a changing climate.

Aggressive conservation might also mean killing off newcomer species to preserve or make room for local flora and fauna; in New Zealand, rat extirpations have helped kakapos survive. In the most extreme case aggressive conservation could involve bringing in new animals to fill the role of animals that have gone extinct.

For example, European sailors ate their way through the Indian Ocean islands of Mauritius, killing off the dodo and the local tortoise species.How humans are driving the sixth mass extinction Scientists have been warning for decades that human actions are pushing life on our shared planet toward mass extinction.

the extinction crisis It's frightening but true: Our planet is now in the midst of its sixth mass extinction of plants and animals — the sixth wave of extinctions in the past half-billion years. We're currently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago.

What is clear, and what is beyond dispute, is that we are living in a time of very, very elevated extinction rates, on the order that you would see in a mass extinction, though a mass extinction.

The sixth mass extinction caused by humans

Jun 20,  · Watch video · Study: 6th mass extinction already underway -- and we're the cause. The Earth's sixth mass extinction is already underway — and humans are the driving force behind it, according to a new study.

Over the last half-billion years, scientists say there have been five mass extinction events on Earth in which a wide diversity of species on this planet suddenly died off. Extinction is a normal part of the evolutionary process, but at certain times in Earth’s history the rate of extinction has greatly exceeded that of normal, or background, species loss.

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Scientists have identified five such events. What caused these five big mass extinction events? What did they.

Earth's sixth mass extinction event under way, scientists warn | Environment | The Guardian