PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Ups and downs of biodiversity after mass extinction

Ups and downs of biodiversity after mass extinction
2012-12-21
(Press-News.org) The climate after the largest mass extinction so far 252 million years ago was cool, later very warm and then cool again. Thanks to the cooler temperatures, the diversity of marine fauna ballooned, as paleontologists from the University of Zurich have reconstructed. The warmer climate, coupled with a high CO2 level in the atmosphere, initially gave rise to new, short-lived species. In the longer term, however, this climate change had an adverse effect on biodiversi-ty and caused species to become extinct.

Until now, it was always assumed that it took flora and fauna a long time to recover from the vast mass extinction at the end of the Permian geological period 252 million years ago. According to the scientific consensus, complex ecological communities only began to reappear in the Middle Triassic, so 247 million years ago. Now, how-ever, a Swiss team headed by paleontologist Hugo Bucher from the University of Zurich reveals that marine animal groups such as ammonoids and conodonts (micro-fossils) already peaked three or four million years earlier, namely still during the Ear-ly Triassic.

The scientists chart the temperature curves in detail in Nature Geoscience, demon-strating that the climate and the carbon dioxide level in the atmosphere fluctuated greatly during the Early Triassic and what impact this had on marine biodiversity and terrestrial plants.

Alternate cooler and very warm phases

For their climate reconstruction, Bucher and his colleagues analyzed the composi-tion of the oxygen isotopes in conodonts, the remains of chordates that once lived in the sea. According to the study, the climate at the beginning of the Triassic 249 mil-lion years ago was cool. This cooler phase was followed by a brief very warm cli-mate phase. At the end of the Early Triassic, namely between 247.9 and 245.9 mil-lion years ago, cooler conditions resumed.

Climate and carbon cycle influence biodiversity

The scientists then examined the impact of the climate on the development of flora and fauna. "Biodiversity increased most in the cooler phases," explains paleontolo-gist Bucher. "The subsequent extremely warm phase, however, led to great changes in the marine fauna and a major ecological shift in the flora." Bucher and his team can reveal that this decline in biodiversity in the warm phases correlates with strong fluctuations in the carbon isotope composition of the atmosphere. These, in turn, were directly related to carbon dioxide gases, which stemmed from volcanic erup-tions in the Siberian Large Igneous Province.

Species emerge and die out

Through the climatic changes, conodont and ammonoid faunae were initially able to recover very quickly during the Early Triassic as unusually short-lived species emerged. However, the removal of excess CO2 by primary producers such as algae and terrestrial plants had adverse effects in the long run: The removal of these vast amounts of organic matter used up the majority of the oxygen in the water. Due to the lack of oxygen in the oceans, many marine species died out. "Our studies reveal that greater climatic changes can lead to both the emergence and extinction of species. Thus, it is important to consider both extinction rates and the rate at which new species emerged," says Bucher.

Bucher and his colleagues are convinced that climate changes and the emission of volcanic gases were key drivers of biotic recovery in the oceans during the Early Tri-assic: Cooler climate phases encourage biological diversification. Warmer climate phases and very high CO2 levels in the atmosphere, however, can have a harmful impact on biodiversity.

INFORMATION:

[Attachments] See images for this press release:
Ups and downs of biodiversity after mass extinction

ELSE PRESS RELEASES FROM THIS DATE:

Strength training improves vascular function in young black men

Strength training improves vascular function in young black men
2012-12-21
CHAMPAIGN, Ill. — Six weeks of weight training can significantly improve blood markers of cardiovascular health in young African-American men, researchers report in the Journal of Human Hypertension. The researchers measured blood markers associated with inflammation, immune response or the remodeling of arteries that normally occur after tissue damage, infection or other types of stress. They found that levels of two of these markers dropped significantly in African-American men but not in Caucasian men after six weeks of resistance training. "This suggests that resistance ...

Physicists take photonic topological insulators to the next level

2012-12-21
AUSTIN, Texas—Researchers at The University of Texas at Austin have designed a simulation that for the first time emulates key properties of electronic topological insulators. Their simulation, which was described this week in Nature Materials, is part of a rapidly moving scientific race to understand and exploit the potential of topological insulators, which are a state of matter that was only discovered in the past decade. These insulators may enable dramatic advances in quantum computing and spintronics. "The discovery of these materials, which are insulators in ...

Targeted gene silencing drugs are more than 500 times more effective with new delivery method

Targeted gene silencing drugs are more than 500 times more effective with new delivery method
2012-12-21
New Rochelle, NY, December 20, 2012—Small interfering RNAs (siRNAs) are a potent new drug class that can silence a disease-causing gene, but delivering them to a target cell can be challenging. An innovative delivery approach that dramatically increases the efficacy of an siRNA drug targeted to the liver and has made it possible to test the drug in non-human primates is described in an article in Nucleic Acid Therapeutics, a peer-reviewed journal from Mary Ann Liebert, Inc. publishers (http://www.liebertpub.com). The article is available on the Nucleic Acid Therapeutics ...

Researchers discover genetic basis for eczema, new avenue to therapies

2012-12-21
CORVALLIS, Ore. – Researchers at Oregon State University today announced the discovery of an underlying genetic cause of atopic dermatitis, a type of eczema most common in infancy that also affects millions of adults around the world with dry, itchy and inflamed skin lesions. The findings were just published in PLoS ONE, a professional journal, and may set the stage for new therapeutic approaches to this frustrating syndrome, which is difficult to treat and has no known cure. Eczema is also related to, and can sometimes cause asthma, a potentially deadly immune dysfunction. Pharmaceutical ...

Extending steroid treatment does not benefit children with hard-to-treat kidney disease

2012-12-21
Highlights Six months of steroid treatment in children with nephrotic syndrome did not reduce relapse rates or side effects compared with three months of treatment. Because many children with nephrotic syndrome face frequent relapses, future research should focus on preventing relapses through new treatment strategies. Nephrotic syndrome has an estimated incidence of two to seven cases per 100,000 children and a prevalence of nearly 16 cases per 100,000. Washington, DC (December 20, 2012) — Extending steroid treatment for the most common form of kidney disease ...

New target for treating prediabetes in patients with kidney disease

2012-12-21
Highlights Retention of certain compounds that are normally excreted by the kidneys may cause insulin resistance, or prediabetes, in kidney disease patients. When mice with kidney disease were treated with a prebiotic that reduces blood levels of these compounds, insulin resistance and lipid abnormalities were prevented. Washington, DC (December 20, 2012) —Insulin resistance, or prediabetes, in individuals with kidney disease may be caused by the progressive retention of certain compounds that are normally excreted by the kidneys in healthy individuals, ...

Science's Breakthrough of the Year: Discovery of the Higgs boson

2012-12-21
The observation of an elusive sub-atomic particle, known as the Higgs boson, has been heralded by the journal Science as the most important scientific discovery of 2012. This particle, which was first hypothesized more than 40 years ago, holds the key to explaining how other elementary particles (those that aren't made up of smaller particles), such as electrons and quarks, get their mass. In addition to recognizing the detection of this particle as the 2012 Breakthrough of the Year, Science and its international nonprofit publisher, AAAS, have identified nine other ...

Wallace's century-old map of natural world updated

Wallaces century-old map of natural world updated
2012-12-21
Until today, Alfred Russell Wallace's century old map from 1876 has been the backbone for our understanding of global biodiversity. Thanks to advances in modern technology and data on more than 20,000 species, scientists from University of Copenhagen have now produced a next generation map depicting the organisation of life on Earth. Published online in Science Express today, the new map provides fundamental information regarding the diversity of life on our planet and is of major significance for future biodiversity research. An essential question in understanding life ...

Unlocking new talents in nature

2012-12-21
PASADENA, Calif.—Protein engineers at the California Institute of Technology (Caltech) have tapped into a hidden talent of one of nature's most versatile catalysts. The enzyme cytochrome P450 is nature's premier oxidation catalyst—a protein that typically promotes reactions that add oxygen atoms to other chemicals. Now the Caltech researchers have engineered new versions of the enzyme, unlocking its ability to drive a completely different and synthetically useful reaction that does not take place in nature. The new biocatalysts can be used to make natural products—such ...

To outsmart malarial drug resistance, research team develops new whole-plant strategy

To outsmart malarial drug resistance, research  team develops new whole-plant strategy
2012-12-21
AMHERST, Mass. – Malaria brings misery and death to millions in the developing world each year, and fighting it keeps medical researchers up at night because the mosquito-borne parasite Plasmodium falciparum, which causes the deadliest form of the disease, has developed resistance to every drug thrown at it. Resistance has cut short the useful life of nearly every therapy tried so far, experts say. But now molecular parasitologist Stephen Rich at the University of Massachusetts Amherst has led a research team who report a promising new low-cost combined therapy with a ...

LAST 30 PRESS RELEASES:

Signs identified that precede sudden arrhythmic death syndrome in young people

Discovery of bacteria's defence against viruses becomes a piece of the puzzle against resistance

Pre-eclampsia is associated with earlier onset and higher incidence of cardiovascular risk factors

Warwick astronomers discover doomed pair of spiralling stars on our cosmic doorstep

Soil conditions significantly increase rainfall in world’s megastorm hotspots

NK cells complexed with bispecific antibody yield high response rates in patients with lymphoma

Planetary health diet and mediterranean diet associated with similar survival and sustainability benefits

Singapore launches national standard to validate antimicrobial disinfectant products

Molecular stool test could improve detection of tuberculosis in adults with HIV

Suspected fibrocartilaginous embolus in Asian small-clawed otter (Aonyx cinereus)

Enhancing heat transfer using the turbulent flow of viscoelastic fluids

Exercise as an anti-ageing intervention to avoid detrimental impact of mental fatigue

UMass Amherst Nursing Professor Emerita honored as ‘Living Legend’

New guidelines aim to improve cystic fibrosis screening

Picky eaters by day, buffet by night: Butterfly, moth diets sync to plant aromas

Pennington Biomedical’s Dr. Leanne Redman honored with the E. V. McCollum Award from the American Society for Nutrition

CCNY physicists uncover electronic interactions mediated via spin waves

Researchers’ 3D-printing formula may transform future of foam

Nurture more important than nature for robotic hand

Drug-delivering aptamers target leukemia stem cells for one-two knockout punch

New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New sea grant report helps great lakes fish farmers navigate aquaculture regulations

Strain “trick” improves perovskite solar cells’ efficiency

How GPS helps older drivers stay on the roads

Estrogen and progesterone stimulate the body to make opioids

Dancing with the cells – how acoustically levitating a diamond led to a breakthrough in biotech automation

Machine learning helps construct an evolutionary timeline of bacteria

Cellular regulator of mRNA vaccine revealed... offering new therapeutic options

Animal behavioral diversity at risk in the face of declining biodiversity

Finding their way: GPS ignites independence in older adult drivers

[Press-News.org] Ups and downs of biodiversity after mass extinction