Spatial patterns of demography and genetic processes across the species' range: Null hypotheses for landscape conservation genetics

• Published in: Conservation genetics Vol. 4; no. 5; pp. 639 - 645
• Main Authors: Vucetich, John A, Waite, Thomas A
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.01.2003
• Subjects: Conservation genetics; Demography; Genetic diversity; Genetics; Population number
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1023/A:1025671831349

Compared with populations near the core of aspecies' range, edge populations tend to becharacterized by low density and high temporalvariation. Based on empirical studiesquantifying this pattern, we show thateffective population size (N^sub e^)could be 2 to 30 times greater near the coreof the species' range than near the edge ofthe range. Hence, the rate of genetic driftmay be 2 to 30 times greater near the edge ofthe range. Despite these strong spatialpatterns in N^sub e^, empirical findingsindicate that peripheral populations sometimeshave less but sometimes have more geneticdiversity than core populations. Our analysisindicates that this variation can be explainedby uncertainty in spatial patterns ofmigration rates. Nevertheless, our analysis:(1) provides a framework or null hypothesis forempirically assessing how spatial patterns ofmigration or selection influence large-scalespatial patterns of genetic diversity, (2)highlights the potential importance ofcontemporary processes, such as spatialpatterns in N^sub e^ (cf. historicalphenomena, such as range expansion) in thedevelopment and maintenance of large-scalespatial patterns in genetic diversity, and (3) provides new context for understanding the conservation value and vulnerability of peripheralpopulations. The conservation ofecological/evolutionary processes requiresunderstanding large scale spatial patterns ofdemographic and genetic processes such as thatdescribed here.[PUBLICATION ABSTRACT]