When Sifrhippus sandae, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale.
It weighed in at around 12 pounds–and it was destined to get much smaller over the ensuing millennia.
Sifrhippus lived during the Paleocene-Eocene Thermal Maximum (PETM), a 175,000-year interval of time some 56 million years ago in which average global temperatures rose by about 10 degrees Fahrenheit. (more…)
Susan Gibbons began a five-year term as University librarian in July 2011. In that role, she oversees one of the largest university libraries in North America, which includes over 12.5 million volumes housed in 18 different libraries.
Before coming to Yale, Gibbons worked at the University of Rochester, where she began as digital initiatives librarian in 2000. In 2008, she was appointed vice provost and dean of the River Campus Libraries.
Gibbons took time out of her hectic schedule to meet with YaleNews. The following is an edited transcript of that conversation. (more…)
Humans pump thousands of tons of vapor from the metallic element mercury into the atmosphere each year, and it can remain suspended for long periods before being changed into a form that is easily removed from the atmosphere.
New research shows that the upper troposphere and lower stratosphere work to transform elemental mercury into oxidized mercury, which can easily be deposited into aquatic ecosystems and ultimately enter the food chain. (more…)
*Climate changes profoundly influenced the rise and fall of six distinct, successive waves of mammal species diversity in North America over the last 65 million years, shows a novel statistical analysis led by Brown University evolutionary biologists. Warming and cooling periods, in two cases confounded by species migrations, marked the transition from one dominant grouping to the next.*
PROVIDENCE, R.I. [Brown University] — History often seems to happen in waves — fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity or “evolutionary faunas.” What force of history determined the destiny of these groupings? The numbers say it was typically climate change.
“Although we’ve always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion,” said Christine Janis, professor of evolutionary biology at Brown University. “We show that the rise and fall of these faunas is indeed correlated with climatic change — the rise or fall of global paleotemperatures — and also influenced by other more local perturbations such as immigration events.” (more…)
Dmitri Talapin, associate professor in chemistry, was one of 10 young scientists from around the world who delivered a message that “Scientific Research is a Global Necessity” to political, scientific and business leaders participating in the 2011 Science and Technology in Society forum last October in Kyoto, Japan.
PASADENA, Calif. – By 2100, global climate change will modify plant communities covering almost half of Earth’s land surface and will drive the conversion of nearly 40 percent of land-based ecosystems from one major ecological community type – such as forest, grassland or tundra – toward another, according to a new NASA and university computer modeling study.
Researchers from NASA’s Jet Propulsion Laboratory and the California Institute of Technology in Pasadena, Calif., investigated how Earth’s plant life is likely to react over the next three centuries as Earth’s climate changes in response to rising levels of human-produced greenhouse gases. Study results are published in the journal Climatic Change.(more…)
COLLEGE PARK, Md. – Over the past decade, attacks and plots by homegrown terrorists in the United States have increased, the work of extremists from across the political spectrum – roughly 40 percent of it by so-called ‘lone wolf,’ non-aligned actors – says an analysis by the National Consortium for the Study of Terrorism and Responses to Terrorism (START) based at the University of Maryland.
*Berkeley Lab scientists help automate the search for hurricanes and other storms in huge datasets*
You’d think that spotting a category 5 hurricane would never be difficult. But when the hurricane is in a global climate model that spans several decades, it becomes a fleeting wisp among mountains of data.
That’s a problem. As scientists develop ever-more sophisticated computer models to predict the effects of climate change, one of the things they’ll look for are changes in the frequency of extreme weather events such as hurricanes and heavy precipitation. The more data generated by models, however, the more difficult it is to quantify these rare but potent events. (more…)
