Monthly Archive for June, 2011

From ScienceDaily

The first organisms to emerge after an ancient worldwide glaciation likely evolved hardy survival skills, arming themselves with tough exteriors to weather a frozen climate.

Researchers at MIT, Harvard University and Smith College have discovered hundreds of microscopic fossils in rocks dating back nearly 710 million years, around the time when the planet emerged from a global glaciation, or “Snowball Earth,” event. The fossils are remnants of tiny, amoeba-like organisms that likely survived the harsh post-glacial environment by building armor and reaching out with microscopic “feet” to grab minerals from the environment, cobbling particles together to make protective shells.

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Image Courtesy of Tanja Bosak

Image Courtesy of Araújo et al

From ScienceDaily

Europe has the world’s most extensive network of conservation areas but they are selected without taking the effects of climate change into account. A team of European researchers, led by Spaniards, has shown for the first time that this phenomenon threatens these areas, including those of the network Red Natura 2000. The impact will be greater in southern countries like Spain.

The study, which has been published in Ecology Letters, is the first “exhaustive” evaluation of the effects of climate change on species’ range in the protected areas of 38 European countries and those in Red Natura 2000.

“The models predict that towards the end of the 21^st century, some 58% of Europe’s terrestrial vertebrates and plants may no longer have suitable climatic conditions to survive in the protected areas of each country,” says Miguel B. Araújo, lead author and researcher in the department of Biodiversity and Evolutionary Biology at Spain’s National Natural History Museum (CSIC).

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Image courtesy of Paul Sunnucks

By Carl Zimmer

Over the past 540 million years, life on Earth has passed through five great mass extinctions. In each of those catastrophes, an estimated 75 percent or more of all species disappeared in a few million years or less.

For decades, scientists have warned that humans may be ushering in a sixth mass extinction, and recently a group of scientists at the University of California, Berkeley, tested the hypothesis. They applied new statistical methods to a new generation of fossil databases. As they reported last month in the journal Nature, the current rate of extinctions is far above normal. If endangered species continue to disappear, we will indeed experience a sixth extinction, over just the next few centuries or millennia.

The Berkeley scientists warn that their new study may actually grossly underestimate how many species could disappear. So far, humans have pushed species toward extinctions through means like hunting, overfishing and deforestation. Global warming, on the other hand, is only starting to make itself felt in the natural world. Many scientists expect that as the planet’s temperature rises, global warming could add even more devastation. “The current rate and magnitude of climate change are faster and more severe than many species have experienced in their evolutionary history,” said Anthony Barnosky, the lead author of the Nature study.

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