Tag: mass extinction

Is there an extinction of global biodiversity in progress?

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The history of life on Earth has been marked five times by events of mass biodiversity extinction caused by extreme natural phenomena. Today, many experts warn that a Sixth Mass Extinction crisis is underway, this time entirely caused by human activities…

“Drastically increased rates of species extinctions and declining abundances of many animal and plant populations are well documented, yet some deny that these phenomena amount to mass extinction,” said Robert Cowie, lead author of the study and research professor at the UH Mānoa Pacific Biosciences Research Center in the School of Ocean and Earth Science and Technology (SOEST). “This denial is based on a biased view of the crisis which focuses on mammals and birds and ignores invertebrates, which of course constitute the great majority of biodiversity.”

Unfortunately, along with science denial taking a foothold in modern society on a range of issues, the new study points out that some people also deny that the Sixth Extinction has begun. Additionally, others accept it as a new and natural evolutionary trajectory, as humans are just another species playing their natural role in Earth’s history. Some even consider that biodiversity should be manipulated solely for the benefit of humanity – but benefit defined by whom?

“Humans are the only species capable of manipulating the biosphere on a large scale,” Cowie emphasized. “We are not just another species evolving in the face of external influences. In contrast, we are the only species that has conscious choice regarding our future and that of Earth’s biodiversity.”

If in fact a debate on this state of affairs takes place in timely fashion, who gets to choose participants? No doubt, scientists in many lands will be chosen to represent their nation’s responsibility by professional organizations…in cooperation with national government. Here in the GOUSA, I’m not as certain.

Brief history of extinctions on Earth

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“Our planet Earth has extinguished large portions of its inhabitants several times since the dawn of animals. And if science tells us anything, it will surely try to kill us all again. Working in the 19th century, paleontology pioneer Georges Cuvier saw dramatic turnovers of life in the fossil record and likened them to the French Revolution, then still fresh in his memory.

Today, we refer to such events as “mass extinctions,” incidents in which many species of animals and plants died out in a geological instant. They are so profound and have such global reach that geological time itself is sliced up into periods—Permian, Triassic, Cretaceous—that are often defined by these mass extinctions.

RTFA and “enjoy” or at least reflect upon the mortality of this widespread but fragile species.

Thanks, Barry Ritholtz

Earth’s 6th mass extinction is now underway

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Click to enlarge — Hainan Black-Crested Gibbon

Deforestation, climate change and the dramatic impact human societies have had in reshaping the Earth for the past few thousand years are taking an extraordinary toll on its animal species, which are dying off about 1,000 times faster today than they did before humans arrived.

It all adds up to the sixth mass extinction in the planet’s history, the editors of Science Magazine report in a special series of scientific studies…which both explore the implications of “anthropocene defaunation” and offer prescriptions for how we might re-colonize animal populations throughout the world…

Scientists point out that extinctions of individual species aren’t uncommon, as more than 99 percent of all the known species ever to have existed on Earth are now gone forever.

What has changed is the speed with which species are going extinct, a phenomenon scientists chalk up to the impact humans have had on the planet for the past two centuries. Many argue we should call the age we’re living in the “Anthropocene,” or the Age of Man.

That’s because the impact humans are having on the planet and its ecosystems — killing off species by destroying their habitats for building cities and agriculture, hunting them and overfishing them to extinction, and by the industrial pollutants we pump into the atmosphere, and into our lakes, rivers and oceans — are so dramatic that they constitute a definable geological time scale for the planet like the Holocene or the Pleistocene…

Earth has experienced five previous mass extinction events, most caused by giant meteors slamming into the Earth. The best-known of these is probably the one that killed off the dinosaurs, along with 75 percent of all other species, about 66 million years ago. Ninety percent of all animal species were lost in another extinction more than 250 million years ago, which has been called the “Great Dying.”

What’s different about today’s extinction? “The underlying driving force for this is not a meteorite or a mega-volcanic eruption; it is one species – homo sapiens“…

“Though for emotional or aesthetic reasons we may lament the loss of large charismatic species, such as tigers, rhinos, and pandas, we now know that loss of animals, from the largest elephant to the smallest beetle, will also fundamentally alter the form and function of the ecosystems upon which we all depend,” the study says.

Read the full special report on “Vanishing Fauna” at Science.

The significant difference about this horribly negative event is that – not only is this mass extinction to a large extent preventable – the creatures who are the cause, so far, are doing so little to prevent the extinction that we may end up including ourselves among the victims.

Thanks, Mike