Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Earth Science News .




CLIMATE SCIENCE
Extreme climate change linked to early animal evolution
by Staff Writers
Riverside, CA (SPX) Oct 01, 2012


This photo shows researchers studying exposures of the Doushanto Formation. Located in China, the formation is most notable for its scientific contributions in the hunt for Precambrian life. Credit: M. Kennedy.

An international team of scientists, including geochemists from the University of California, Riverside, has uncovered new evidence linking extreme climate change, oxygen rise, and early animal evolution.

A dramatic rise in atmospheric oxygen levels has long been speculated as the trigger for early animal evolution. While the direct cause-and-effect relationships between animal and environmental evolution remain topics of intense debate, all this research has been hampered by the lack of direct evidence for an oxygen increase coincident with the appearance of the earliest animals - until now.

In the Sept. 27 issue of the journal Nature, the research team, led by scientists at the University of Nevada, Las Vegas, offers the first evidence of a direct link between trends in early animal diversity and shifts in Earth system processes.

The fossil record shows a marked increase in animal and algae fossils roughly 635 million years ago. An analysis of organic-rich rocks from South China points to a sudden spike in oceanic oxygen levels at this time - in the wake of severe glaciation. The new evidence pre-dates previous estimates of a life-sustaining oxygenation event by more than 50 million years.

"This work provides the first real evidence for a long speculated change in oxygen levels in the aftermath of the most severe climatic event in Earth's history - one of the so-called 'Snowball Earth' glaciations," said Timothy Lyons, a professor of biogeochemistry at UC Riverside.

The research team analyzed concentrations of trace metals and sulfur isotopes, which are tracers of early oxygen levels, in mudstone collected from the Doushantuo Formation in South China. The team found spikes in concentrations of the trace metals, denoting higher oxygen levels in seawater on a global scale.

"We found levels of molybdenum and vanadium in the Doushantuo Formation mudstones that necessitate that the global ocean was well ventilated. This well-oxygenated ocean was the environmental backdrop for early animal diversification," said Noah Planavsky, a former UCR graduate student in Lyons's lab now at CalTech.

The high element concentrations found in the South China rocks are comparable to modern ocean sediments and point to a substantial oxygen increase in the ocean-atmosphere system around 635 million years ago.

According to the researchers, the oxygen rise is likely due to increased organic carbon burial, a result of more nutrient availability following the extreme cold climate of the 'Snowball Earth' glaciation when ice shrouded much of Earth's surface.

Lyons and Planavsky argued in research published earlier in the journal Nature that a nutrient surplus associated with the extensive glaciations may have initiated intense carbon burial and oxygenation. Burial of organic carbon - from photosynthetic organisms - in ocean sediments would result in the release of vast amounts of oxygen into the ocean-atmosphere system.

"We are delighted that the new metal data from the South China shale seem to be confirming these hypothesized events," Lyons said.

The joint research was supported by grants from the National Science Foundation, the NASA Exobiology Program, and the National Natural Science Foundation of China. Besides Lyons and Planavsky, the research team includes Swapan K. Sahoo (first author of the research paper) and Ganqing Jiang (principal investigator of the study) of the University of Nevada, Las Vegas; Brian Kendall and Ariel D. Anbar of Arizona State University; Xinqiang Wang and Xiaoying Shi of the China University of Geosciences (Beijing); and UCR alumnus Clint Scott of United States Geological Survey.

.


Related Links
University of California - Riverside
Climate Science News - Modeling, Mitigation Adaptation






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





CLIMATE SCIENCE
Loss of species makes nature more sensitive to climate change
Gothenburg, Sweden (SPX) Sep 27, 2012
High biodiversity acts as an insurance policy for nature and society alike as it increases the likelihood that at least some species will be sufficiently resilient to sustain important functions such as water purification and crop pollination in a changing environment. "It's the same principle as an investment portfolio - you'd be mad to put all your eggs in one basket," says researcher Jo ... read more


CLIMATE SCIENCE
World facing unprecedented refugee crisis: UNHCR

Twenty-five killed in Hong Kong ferry collision: official

Libyans surrender hundreds of weapons to army

Seven Britons, five Chinese dead in Nepal air crash: police

CLIMATE SCIENCE
HP powers business tablet with Windows 8

'MindMeld' app anticipates people's needs

Search for element 113 concluded at last

Kodak dumps inkjet printers, more jobs

CLIMATE SCIENCE
China's dams a threat to the Mekong

Great Barrier Reef coral halved in 27 years: study

Scaling down: Warming will make fish smaller

Jordanian thirst for water grows

CLIMATE SCIENCE
Australian tycoon fined for Arctic party cruise

Study: Arctic warming faster than before

Rudolph unfed loathes rain, dear

Melting Arctic ice cap at record low

CLIMATE SCIENCE
Plant scientists create 'see-through' soil

Ex-Aussie PM criticises UN on food security

Argentina looks to soybean windfall

Italy's Slow Food movement prepares giant food fair

CLIMATE SCIENCE
Nigeria seasonal floods kill 148: Red Cross

Powerful typhoon hits Japan mainland

Typhoon Jelawat on course to hit mainland Japan

Toll from Spain floods rises to 10: regional officials

CLIMATE SCIENCE
Nigeria seeks to end the curse of unfinished projects

Ivory Coast opens first major trial of soldiers in political crisis

France to facilitate Mali anti-rebel force

One-third of Lesotho faces food crisis: UN food agency

CLIMATE SCIENCE
Compelling evidence that brain parts evolve independently

Anti-aging pill being developed

Human Brains Develop Wiring Slowly, Differing from Chimpanzees

Breaking up harder to do on Facebook




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement