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Journal Article

Genetic Diversity Declines Toward Species' Range Edges, While Population Abundance and Growth Rate Show no Clear Trend

Jacob K. Moutouama; Orou G. Gaoue
Journal of Biogeography · Vol. 53, Issue 4 · 2026

Abstract

The centre‐periphery hypothesis (CPH) predicts that species exhibit higher abundance, demographic performance and genetic diversity at the centres of their geographic ranges than at their margins. This pattern is commonly attributed to stronger biotic interactions and declining habitat quality toward range edges. Recent reviews on the hypothesis assessed the prevalence of the centre‐periphery hypothesis using a vote‐counting approach. Aim We quantified how population performance changes toward species range edge and aimed to identify the factors that moderate these patterns. Location Africa, America, Asia and Europe. Time Period 1960–2024. Major Taxa Studied Plants and animals. Methods We performed a meta‐analysis of 105 studies to quantify spatial trends in population performance predicted by the centre‐periphery hypothesis. Using meta‐regression, we assessed how distance from range and niche centre, species traits (body mass, seed mass, growth form and pollination mode) and taxonomic kingdom influence population performance. Results Genetic diversity declined toward species' range edges, whereas population growth rate and abundance showed weak and highly variable spatial patterns. Species traits, taxonomic kingdom and distance metrics did not explain the variation in species performance at range edges. Main Conclusions Reduced genetic diversity at species range margins combined with the absence of consistent demographic decline at range edges suggests that species range limits are governed by more complex processes than commonly used population performance metrics can capture. The limited explanatory power of traits, taxonomic groups and distance measures highlights the need for mechanistic frameworks that integrate ecological and evolutionary dynamics to better understand the determinants of species' range limits.

Bibliographic Information

JournalJournal of Biogeography
PublisherWiley
Publication Date2026-04-01
Publication Year2026
Volume53
Issue4
Document TypeJournal Article
Print ISSN0305-0270
eISSN1365-2699
DOI10.1111/jbi.70233
SubjectEcology & Organismal Biology

Access Information

NARA Access Coverage1997-01-01~Current
Journal Homepagehttps://onlinelibrary.wiley.com/loi/13652699
Publisher PageOpen Publisher Page
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