Charles Darwin University

CDU eSpace
Institutional Repository

 
CDU Staff and Student only
 

Most species are not driven to extinction before genetic factors impact them

Spielman, D., Brook, Barry W. and Frankham, Richard (2004). Most species are not driven to extinction before genetic factors impact them. Proceedings of the National Academy of Sciences of the USA,101(42):15261-15264.

Document type: Journal Article
Citation counts: Scopus Citation Count Cited 340 times in Scopus Article | Citations
Altmetric Score Altmetric Score is 21
Google Scholar Search Google Scholar

Title Most species are not driven to extinction before genetic factors impact them
Author Spielman, D.
Brook, Barry W.
Frankham, Richard
Journal Name Proceedings of the National Academy of Sciences of the USA
Publication Date 2004
Volume Number 101
Issue Number 42
ISSN 0027-8424   (check CDU catalogue open catalogue search in new window)
Scopus ID 2-s2.0-6344258124
Start Page 15261
End Page 15264
Total Pages 4
Place of Publication Washington, YSA
Publisher The National Academy of Sciences of the USA
HERDC Category C1 - Journal Article (DEST)
Abstract There is controversy concerning the role of genetic factors in species extinctions. Many authors have asserted that species are usually driven to extinction before genetic factors have time to impact them, but few studies have seriously addressed this issue. If this assertion is true, there will be little difference in genetic diversity between threatened and taxonomically related nonthreatened species. We compared average heterozygosities in 170 threatened taxa with those in taxonomically related nonthreatened taxa in a comprehensive metaanalysis. Heterozygosity was lower in threatened taxa in 77% of comparisons, a highly significant departure from the predictions of the no genetic impact hypothesis. Heterozygosity was on average 35% lower (median 40%) in threatened taxa than in related nonthreatened ones. These differences in heterozygosity indicate lowered evolutionary potential, compromised reproductive fitness, and elevated extinction risk in the wild. Independent evidence from stochastic computer projections has demonstrated that inbreeding depression elevates extinction risk for threatened species in natural habitats when all other threatening processes are included in the models. Thus, most taxa are not driven to extinction before genetic factors affect them adversely.
Keywords effective population-size
inbreeding depression
conservation biology
island populations
drosophila
diversity
fitness
ratios
DOI http://dx.doi.org/10.1073/pnas.0403809101   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)
 
Versions
Version Filter Type
Access Statistics: 49 Abstract Views  -  Detailed Statistics
Created: Fri, 12 Sep 2008, 08:35:25 CST by Administrator