Featured Research

from universities, journals, and other organizations

In Evolution Game, Survival Doesn't Equal Success; Finding Has Implications For Future Of Biodiversity

Date:
June 11, 2002
Source:
National Science Foundation
Summary:
A significant number of organisms that survived the five greatest mass extinctions in Earth's history subsequently failed to achieve evolutionary success, according to a new study funded by the National Science Foundation (NSF) and conducted by University of Chicago scientist David Jablonski.

A significant number of organisms that survived the five greatest mass extinctions in Earth's history subsequently failed to achieve evolutionary success, according to a new study funded by the National Science Foundation (NSF) and conducted by University of Chicago scientist David Jablonski.

"It's clear that there is a lot of evolutionary action in the aftermath of mass extinctions," said Jablonski. "During the rebound from mass extinctions, it's not an all-or-nothing thing. The shape of the post-extinction world comes not only from who goes extinct, but from which survivors are successful – or, instead, become extinct or marginalized in the aftermath."

Jablonski lays out his evidence in the June 11 issue of the journal, Proceedings of the National Academy of Sciences. The research was also supported by the Guggenheim Foundation.

"Because most extinction event survivor organisms rebound so robustly, paleontological studies are generally focused on these evolutionary winners," explains Richard Lane, director of NSF's paleontology program. "Jablonski's research examines why other groups of organisms weakly struggle through these major catastrophic events only to meet their demise somewhat later, geologically speaking."

To test the idea that many survivors go on to lose the evolutionary game, Jablonski turned to the paleontological literature and to his own work on the aftermath of mass extinction at the end of the Mesozoic Era. In a global analysis of marine genera, he determined how many lineages survived each of the largest mass extinctions in Earth's history only to die off within the first five or 10 million years thereafter.

Patterns at higher levels of biological organization - for example, orders that include a large number of genera - often play out differently. However, Jablonski also found a 17 percent extinction rate for orders following three of the five big mass extinctions.

This result surprised Jablonski, who had assumed that survival of a mass extinction would be good news for most major groups. "It wasn't good news for everybody, even at this level," he said.

These sets of doomed survivors are the last representatives of their clades, a technical term for an evolutionary group of organisms that includes an ancestor and all of its descendants. Jablonski creates a special category for them in his article, calling them "Dead Clade Walking," in homage to the 1995 film "Dead Man Walking," about a death-row inmate.

Paleontologists still poorly understand the process that sorts the winners from the losers after a major extinction, Jablonski said. His statistical analysis ruled out one of the most straightforward of possible causes - that lineages that have suffered a major blow to their numbers during a mass extinction might be especially extinction-prone in the aftermath because they contain fewer species to buffer against the hard times. Instead, Jablonski found that many of the biggest post-extinction winners had passed through a diversity bottleneck as narrow as the Dead Clade Walking groups.

Other possible causes include environmental change and increased competition between species. Both issues need further study, Jablonksi said, and there are probably examples of each in the fossil record.


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "In Evolution Game, Survival Doesn't Equal Success; Finding Has Implications For Future Of Biodiversity." ScienceDaily. ScienceDaily, 11 June 2002. <www.sciencedaily.com/releases/2002/06/020611071328.htm>.
National Science Foundation. (2002, June 11). In Evolution Game, Survival Doesn't Equal Success; Finding Has Implications For Future Of Biodiversity. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2002/06/020611071328.htm
National Science Foundation. "In Evolution Game, Survival Doesn't Equal Success; Finding Has Implications For Future Of Biodiversity." ScienceDaily. www.sciencedaily.com/releases/2002/06/020611071328.htm (accessed August 23, 2014).

Share This




More Plants & Animals News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Farm Resurgence Grows With Younger Crowd

Farm Resurgence Grows With Younger Crowd

AP (Aug. 22, 2014) New England farms are seeing a surge in younger farm hands as the 'buy local' food movement grows across the country. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) According to a new study, spiders that live in cities are bigger, fatter and multiply faster. 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:
from the past week

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