Featured Research

from universities, journals, and other organizations

Oxygen Theory Of Mass Extinction Questioned By New Research Findings

Date:
September 10, 2008
Source:
Dublin, University College
Summary:
Several theories have been proposed by scientists to explain the two mass extinction events which took place on the earth 250 and 200 million years ago. The Permian-Triassic catastrophe (250 million years ago) was the worst of all five of the mass extinction events to ever have befallen the earth. It eradicated almost 95% of all species, 53% of marine families, 84% of marine genera and an approximated 70% of all land species including plants, insects and vertebrate animals.

Several theories have been proposed by scientists to explain the two mass extinction events which took place on the earth 250 and 200 million years ago.

Related Articles


The Permian-Triassic catastrophe (250 million years ago) was the worst of all five of the mass extinction events to ever have befallen the earth. It eradicated almost 95% of all species, 53% of marine families, 84% of marine genera and an approximated 70% of all land species including plants, insects and vertebrate animals.

Many scientists suspect that the event was the result of a comet or an asteroid colliding with the earth. Others believe that flood volcanism from the Siberian Traps and the associated oxygen loss in the seas was the cause. While others continue to investigate the possibility that thinning levels of atmospheric oxygen caused the eradication of so many species at the time.

But new research findings by University College Dublin scientists published in Science question the theory of falling oxygen levels as a mechanism for causing the mass extinction events.

To assess the likely atmospheric oxygen levels at the time of the mass extinction events, using purposefully designed walk-in-plant-growth rooms equipped with thermal imaging system and full atmospheric, temperature and humidity control, Dr Claire Belcher and her University College Dublin colleagues spent several months measuring the lower limits of oxygen at which combustion can occur.

When the measurements were recorded, they compared their results with the charcoal in the fossil record from ancient times because the charcoal that remains in the fossil record reveals the presence of ancient wildfires which require a sufficient level of oxygen in the air for plants to burn.

“By performing experimental burns using pine wood, moss, matches, paper and a candle at 20°C in varying ranges of oxygen concentrations and comparing these results to the occurrences of fossil charcoal throughout the Mesozoic (250-65 million years ago), we were able to identify that prolonged periods of low oxygen are unlikely to have occurred,” says Dr Claire Belcher from the School of Biology and Environmental Science, University College Dublin, the lead author of the report.

“Low oxygen atmospheres, less than 12%, are considered to be the primary driver of at least two of the ‘big five’ mass-extinction events,” explains Dr Belcher. “But our research findings question that hypothesis and highlight the need for more detailed studies of fossil charcoal across these mass extinction events.”

This is the first time that research to identify the lower limit of atmospheric oxygen under which combustion can occur have been conducted within fully controlled and realistic environments. The six walk-in chambers at University College Dublin, funded by EU Marie Curie, enable the realistic reconstruction of environmental conditions from the past.


Story Source:

The above story is based on materials provided by Dublin, University College. Note: Materials may be edited for content and length.


Cite This Page:

Dublin, University College. "Oxygen Theory Of Mass Extinction Questioned By New Research Findings." ScienceDaily. ScienceDaily, 10 September 2008. <www.sciencedaily.com/releases/2008/09/080908073751.htm>.
Dublin, University College. (2008, September 10). Oxygen Theory Of Mass Extinction Questioned By New Research Findings. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2008/09/080908073751.htm
Dublin, University College. "Oxygen Theory Of Mass Extinction Questioned By New Research Findings." ScienceDaily. www.sciencedaily.com/releases/2008/09/080908073751.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) — Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) — The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) — A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins