HOME >> BIOLOGY >> NEWS
Life in a greenhouse world

nt component of Earth's atmosphere occurred at the same time as analogous evidence for the first cyanobacteria?'"

Schwartzman and Caldeira followed up the proposal of Charles Dismukes and coworkers that now extinct bacteria were performing oxygen-based photosynthesis before cyanobacteria came onto the scene. In a CO2 dominated world, these early oxygenic photosynthesizers split bicarbonate instead of water as the source of oxygen. They apparently boosted organic productivity and caused greater methane production by methanogens living in the ocean.

"It takes far less methane to maintain climatic temperatures than it does carbon dioxide," says Schwartzman.

As methane became dominant, CO2 levels dropped dramatically. Cyanobacteria then emerged and began oxygenic photosynthesis by splitting water as the source of oxygen. According to Schwartzman, only when atmospheric oxygen levels began to rise some 2.2 billion years ago did a CO2-concentrating mechanism emerge, an adaptation to declining CO2/02 ratios in the external environment.

Thus, global constraints on evolution appeared to have included carbon dioxide as well as oxygen levels in the atmosphere along with surface temperature. All the former have been strongly influenced by biological evolution in a complex set of feedbacks, an essential aspect of biospheric evolution. "The classical paradigm of evolution, that changes in the local environment lead to natural selection, should be rethought to include these feedbacks on a global scale. We hope that our hypothesis will be tested by looking more closely at the extant geologic record of the proposed transition as well as the insights from the study of photosynthesis and molecular biology of modern organisms," says Schwartzman.


'"/>

Contact: Ann Cairns
acairns@geosociety.org
303-357-1056
Geological Society of America
25-Oct-2002


Page: 1 2

Related biology news :

1. Plants will not save us from greenhouse gases
2. Environmental decontamination, greenhouse gases, and the genome of a methane-loving bacterium
3. New space-borne instrument to track greenhouse gases, ozone destroyers, and other pollutants
4. Continents played key role in collapse and regeneration of Earths early greenhouse, geologists say
5. Improved crop production and fewer greenhouse gases
6. UGA researchers track greenhouse gases in forests
7. Scientists find key to ocean bacterium that helps control greenhouse gas
8. Plant diversity threatened by climate change and buildup of greenhouse gas, study reveals
9. Shifts in rice farming practices in China reduce greenhouse gas methane
10. Agricultural science helping farmers reduce greenhouse gas
11. Prospect of greenhouse gas reduction drives biofuels market

Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Life greenhouse world

(Date:8/19/2014)... Efforts must be made to decrease China,s increasing caesarean ... August) in BJOG: An International Journal of Obstetrics ... the highest caesarean delivery rates in the world. Of ... by caesarean. Although the exact rate is not known, ... China reports total caesarean rates ranging from 36% to ...
(Date:8/19/2014)... used in supermarkets to encourage healthier spending habits? A ... that very question by tracking the purchasing records in ... to rate the nutritional value of foods for sale. ... David Just, PhD, and Brian Wansink PhD, author of ... over 150 Hannaford Supermarkets in the Northeastern United States ...
(Date:8/19/2014)... and Network-Level Science, , Imagine if we had the ... was responding to global changes in real time. Such ... multiple decades of information about ecological responses to environmental ... of different ecosystem types. , In fact, this ... Network, which will soon celebrate its 35th anniversary. , ...
Breaking Biology News(10 mins):Is China's 50 percent cesarean section delivery rate too high? 2Is China's 50 percent cesarean section delivery rate too high? 3This week from AGU: Long-term ecological research, predicting cholera outbreaks 2
(Date:8/20/2014)... improve the health of your heart, researchers have discovered. ... a standard TENS machine like those designed to relieve ... the small raised flap at the front of the ... The stimulation changed the influence of the nervous system ... can drive failing hearts too hard. , Professor Jim ...
(Date:8/19/2014)... 19, 2014 Shimadzu Scientific Instruments ... Prominence-i and Nexera-i, adding to the company’s extensive ... functionality, an intuitive operating environment, and full automation, ... efficient workflow for conventional to ultra-high-speed analysis. ... and intelligent design so users can begin building ...
(Date:8/19/2014)... DUBLIN , Aug. 19, 2014 Research ... Oxide Fuel Cells (SOFCs) - Global Strategic Business Report" ... the worldwide markets for Solid Oxide Fuel Cells (SOFCs) in ... US, Canada , Europe ... Annual estimates and forecasts are provided for the period 2012 ...
(Date:8/19/2014)... , Aug. 19, 2014 CSSi, the ... industry, recently announced the formation of the company,s Medical ... announce the addition of Dr. William E. Gannon, ... http://photos.prnewswire.com/prnh/20140818/136957 The MCAB, with ... variety of therapeutic areas and set strategic goals for ...
Breaking Biology Technology:'Tickling' your ear could be good for your heart 2Shimadzu’s New i-Series Integrated Liquid Chromatography Systems Provide Laboratories Wider Range of Analytical Capabilities 2Shimadzu’s New i-Series Integrated Liquid Chromatography Systems Provide Laboratories Wider Range of Analytical Capabilities 3Global Solid Oxide Fuel Cells (SOFCs) - Strategic Business Report 2014 2CSSi Appoints Dr. William E. Gannon, Jr. to Newly Formed Medical and Clinical Advisory Board 2CSSi Appoints Dr. William E. Gannon, Jr. to Newly Formed Medical and Clinical Advisory Board 3
Cached News: