Featured Research

from universities, journals, and other organizations

University Of Cincinnati Geologist Finds Survival Benefit To Evolving After Mass Extinctions

Date:
November 7, 2001
Source:
University Of Cincinnati
Summary:
An evolutionary group has a significantly better chance of surviving for a long time in the geologic record if it first appears right after a mass extinction. University of Cincinnati geologist Arnold Miller will present his findings Tuesday morning Nov. 6 during the annual meeting of the Geological Society of America in Boston.

Cincinnati - An evolutionary group has a significantly better chance of surviving for a long time in the geologic record if it first appears right after a mass extinction.

University of Cincinnati geologist Arnold Miller will present his findings Tuesday morning Nov. 6 during the annual meeting of the Geological Society of America in Boston.

Professor Miller used a database of marine fossil genera compiled by J. John Sepkoski to examine longevity trends throughout the Phanerozoic (the last 540 million years). In four separate cases, he found that genera first appearing following mass extinctions survived for longer periods of time, on average, than those that first appeared at other times.

"There was already a sense that organisms originating in the wakes of mass extinctions were generalists with respect to their geographic and environmental distributions," said Miller. "My analysis indicates that these characteristics promoted evolutionary longevity."

Miller said that the trend is apparent no matter what the ultimate cause was of each mass extinction. Genera that were more widespread, might have fared better over the long run because of a kind of "safety in geography." If a catastrophe decimated the individuals living in one region, then a genus could still survive if individuals belonging to the genus also lived in other regions.

To conduct his analysis, Miller divided the Phanerozoic into 156 "bins" or substages. Then, he looked at the average longevity of genera originating in each bin. Significant peaks in mean longevities occurred in the substages following major mass extinctions in Late Permian, Late Triassic, and Late Cretaceous-three of the "big five" extinctions of the Phanerozoic-and following a lesser, but still significant extinction at the end of the Jurassic.

"These are very sharp peaks," noted Miller, who followed up his first analysis with a number of statistical techniques to weed out artifacts in the data set. "I was trying and trying to kill the pattern, but it wouldn't go away."

One enigma in the analysis is that the pattern does not extend back into the Paleozoic, the earliest of the three eras that comprise the Phanerozoic. Although there were fairly high extinction rates during parts of the Cambrian, Ordovician and Devonian, Miller's analysis showed no clear relationship between extinction events and longevity in any of those periods. "To see nothing is quite something," he said, summing up that intriguing finding.

It is possible that, after the Paleozoic, there was a major change in the dynamics of evolution, but Miller noted that any real explanation for the difference between the Paleozoic and post-Paleozoic remains to be determined.

Miller is currently working with a team of geologists worldwide to build an online database that depicts the occurrences of marine genera throughout the Phanerozoic, and which will incorporate data on the geography and paleoenvironment of each occurrence. In the future, he hopes to use these data to assess directly whether the longer-lived genera really were those with wider geographic and environmental distributions. "We really haven't looked definitively at the characteristics of the post-extinction players, but with the databases we're building, we'll be able to."

Miller's work is supported by NASA's Program in Exobiology and NSF's Program in Biocomplexity.


Story Source:

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


Cite This Page:

University Of Cincinnati. "University Of Cincinnati Geologist Finds Survival Benefit To Evolving After Mass Extinctions." ScienceDaily. ScienceDaily, 7 November 2001. <www.sciencedaily.com/releases/2001/11/011107073104.htm>.
University Of Cincinnati. (2001, November 7). University Of Cincinnati Geologist Finds Survival Benefit To Evolving After Mass Extinctions. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2001/11/011107073104.htm
University Of Cincinnati. "University Of Cincinnati Geologist Finds Survival Benefit To Evolving After Mass Extinctions." ScienceDaily. www.sciencedaily.com/releases/2001/11/011107073104.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Trick-or-Treating Banned Because of Polar Bears

Trick-or-Treating Banned Because of Polar Bears

Buzz60 (Oct. 21, 2014) Mother Nature is pulling a trick on the kids of Arviat, Canada. As Mara Montalbano (@maramontalbano) tells us, the effects of global warming caused the town to ban trick-or-treating this Halloween. Video provided by Buzz60
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
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