Ancient Alteration of Seawater Chemistry Linked With Past Climate Change

Dissolution or creation of huge gypsum deposits changed sulfate content of the oceans

Scientists have discovered a potential cause of Earth's "icehouse climate" cooling trend of the past 45 million years. It has everything to do with the chemistry of the world's oceans.

"Seawater chemistry is characterized by long phases of stability, which are interrupted by short intervals of rapid change," says geoscientist Ulrich Wortmann of the University of Toronto, lead author of a paper reporting the results and published this week in the journal Science.

"We've established a new framework that helps us better interpret evolutionary trends and climate change over long periods of time. The study focuses on the past 130 million years, but similar interactions have likely occurred through the past 500 million years."

Wortmann and co-author Adina Paytan of the University of California Santa Cruz point to the collision between India and Eurasia approximately 50 million years ago as one example of an interval of rapid change.

This collision enhanced dissolution of the most extensive belt of water-soluble gypsum on Earth, stretching from Oman to Pakistan and well into western India. Remnants of the collision are exposed in the Zagros Mountains in western Iran.

The dissolution or creation of such massive gypsum deposits changes the sulfate content of the ocean, say the scientists, affecting the amount of sulfate aerosols in the atmosphere and thus climate.

"We propose that times of high sulfate concentrations in ocean water correlate with global cooling, just as times of low concentrations correspond with greenhouse [warmer] periods," says Paytan.

"When India and Eurasia collided, it caused dissolution of ancient salt deposits, which resulted in drastic changes in seawater chemistry."

That may have led to the end of the Eocene epoch--the warmest period of the modern-day Cenozoic era--and the transition from a greenhouse to an icehouse climate. "It culminated in the beginning of the rapid expansion of the Antarctic ice sheet," says Paytan.

Canada's Natural Sciences and Engineering Research Council supports Wortmann's research and the U.S. National Science Foundation (NSF) supports Paytan research.

"Abrupt changes in seawater composition are a new twist in our understanding of the links among ocean chemistry, plate tectonics, climate and evolution," says Candace Major, program director in NSF's Division of Ocean Sciences.

To make the discovery, the researchers combined past seawater sulfur composition data collected by Paytan with Wortmann's recent discovery of the strong link between marine sulfate concentrations and carbon and phosphorus cycling.

They found that seawater sulfate reflects huge changes in the accumulation and weathering of gypsum, which is the mineral form of hydrated calcium sulfate.

"While it's been known for a long time that gypsum deposits can be formed and destroyed rapidly, the effect of these processes on seawater chemistry has been overlooked," says Wortmann.

"The idea represents a paradigm shift in our understanding of how ocean chemistry changes over time, and how these changes are linked with climate."

Data used in the research were collected aboard the ocean drillship JOIDES Resolution and through the Integrated Ocean Drilling Program (IODP).

IODP is an international research program dedicated to advancing scientific understanding of the Earth through drilling, coring and monitoring the subseafloor.

The JOIDES Resolution is a scientific research vessel managed by the U.S. Implementing Organization of IODP. Texas A&M University, Lamont-Doherty Earth Observatory of Columbia University and the Consortium for Ocean Leadership comprise the implementing organization.

Two lead agencies support the IODP: the U.S. NSF and Japan's Ministry of Education, Culture, Sports, Science and Technology.

Additional program support comes from the European Consortium for Ocean Research Drilling, the Australia-New Zealand IODP Consortium, India's Ministry of Earth Sciences, the People's Republic of China's Ministry of Science and Technology, and the Korea Institute of Geoscience and Mineral Resources.

 -NSF-

Fossil Snake Fed on Hatchling Dinosaurs

This life size reconstruction shows a moment captured in time through a fossil, when a snake coiled around a recently hatched, crushed dinosaur egg adjacent to a hatchling sauropod. The remains of the fossil, unearthed in 67-million-year-old sediments from Gujarat in western India, has given scientists a rare glimpse of an unusual feeding behavior in ancient snakes.

The nearly complete snake was found preserved in the nest of a sauropod dinosaur. The 11.5 foot-long snake, which represents a new species (Sanajeh indicus), was no match for the 1.6 foot-long baby dinosaur that was probably defenseless. Remains of other snake individuals associated with egg clutches at the same site indicate that the newly described snake survived by feeding on young dinosaurs. The arrangement of the bones and delicate structures, such as eggshells and the snake's skull, point to quick entombment.

The discovery was made by an international paleontology team led by Jeff Wilson of the University of Michigan (U-M) and Dhananjay Mohabey of the Geological Survey of India.

"We think that the hatchling had just exited its egg, and that activity attracted the snake," said Mohabey. "The eggs were lain in the loose sands near a small drainage and covered by a thin layer of sediment."

The decade long odyssey required preparation and study of the fossil at U-M's Museum of Paleontology, weeks of museum study in India, and field reconnaissance at the original location in Gujarat by a team that included Wilson, Mohabey, snake expert Jason Head of the University of Toronto-Mississaugua and geologist Shanan Peters of the University of Wisconsin. (Date of Image: 2008)

Credit: Sculpture by Tyler Keillor; original photography by Ximena Erickson; image modified by Bonnie Miljour

New Studies Determine Which Social Class More Likely to Behave Unethically

Unethical behavior tied to attitudes toward greed

A series of studies conducted by psychologists at the University of California, Berkeley and the University of Toronto in Canada reveal something the well off may not want to hear. Individuals who are relatively high in social class are more likely to engage in a variety of unethical behaviors.

That is the finding of new research published in today's Proceedings of the National Academy of Sciences and it's a doozy.

"Our studies suggest that more positive attitudes toward greed and the pursuit of self-interest among upper-class individuals, in part, drive their tendencies toward increased unethical behavior," said lead researcher Paul Piff of UC Berkeley.

The research revealed that relative to the lower class, upper-class individuals are more likely to break the law while driving, more likely to exhibit unethical decision-making tendencies, more likely to take valued goods from others, more likely to lie in a negotiation, more likely to cheat to increase their chances of winning a prize and more likely to endorse unethical behavior at work.

"The relative privilege and security enjoyed by upper-class individuals give rise to independence from others and a prioritization of the self and one's own welfare over the welfare of others--what we call 'greed,'" explained Piff, whose research was funded in part by a National Science Foundation Graduate Research Fellowship.

"This is likely to cause someone to be more inclined to break the rules in his or her favor, or to perceive themselves as, in a sense, being 'above the law,'" he said and therefore become more prone to committing unethical behavior.

Piff and colleagues conducted seven survey, experimental and naturalistic studies to determine which social class is more likely to behave in unethical ways--to engage in behaviors that have important consequences for society such as cheating, deception or breaking the law.

In two naturalistic field studies that examined unethical behavior on the road, researchers were surprised by the differences between upper and lower class individuals. They found "upper-class drivers" were significantly more likely to pursue their own self-interests and break the law while driving than were "lower-class drivers."

Piff and his team found drivers of higher-end automobiles were four times more likely to cut off other vehicles before waiting their turn at a busy, four-way intersection with stop signs on all sides. In addition, they found upper-class drivers were significantly more likely to drive through a crosswalk without yielding to a waiting pedestrian.

For these studies, the researchers defined social class by an observable cultural symbol of social class--namely, the car one drives.

In another laboratory study more directly related to greed, researchers found upper-class individuals were more likely to cheat in a game to improve their chances of winning a cash prize. In this study, Piff and colleagues measured social class using the MacArthur scale of subjective socioeconomic status, where participants rank themselves on a 10-rung ladder relative to others in society in terms of their wealth, education and the prestige of their jobs.

Participants then played a "game of chance" in which a computer "randomly" presented them with one side of a six-sided die on five separate rolls. Researchers told participants higher rolls would increase their chances of winning a cash prize and were asked to report their total score at the end of the game. In fact, die rolls were pre-determined to sum up to 12. The extent to which participants reported a total exceeding 12 served as a direct behavioral measure of cheating.

Greed "is a robust determinant of unethical behavior," the researchers write in the report. "Plato and Aristotle deemed greed to be at the root of personal immorality, arguing that greed drives desires for material gain at the expense of ethical standards." For this study, the researchers conclude that, in part, due to their more favorable beliefs about greed, upper-class individuals are more willing to deceive and cheat others for personal gain.

"Study 4 is also intriguing," said Piff. Study 4 sought to provide experimental evidence that the experience of higher social class has a causal effect on unethical decision-making and behavior. It was the only study in which researchers manipulated participants into temporarily feeling either higher or lower in social class rank to test whether these feelings actually caused people to behave more or less unethically.

At the end of the study, the experimenter presented participants with a jar of individually wrapped candies, ostensibly for children in a nearby laboratory, but informed them that they could take some if they wanted. This task served as a measure of unethical behavior because taking candy would reduce the amount that would otherwise be given to children.

People in this study, who were made to feel higher in social class rank, took approximately two times as much candy from children than did people who were made to feel lower in social class rank.

"Across all seven studies, the general pattern we find is that as a person's social class increases, his or her tendency to behave unethically also increases," said Piff.

Joining Piff in the research were Daniel M. Stancato, Rodolfo Mendoza-Denton and Dacher Keltner of UC Berkeley and Stéphane Côté of the University of Toronto.

-NSF-