Lack of congruence between morphometric evolution and genetic differentiation suggests a recent dispersal and local habitat adaptation of the Madeiran lizard Lacerta dugesii

Niche divergence or conservatism and phenotypic adaptation are important in lineage diversification. We used mitochondrial DNA (mtDNA), morphology and ecological niche models to examine these processes in three subspecies of Sage Sparrow (Artemisiospiza belli belli, A. b. canescens and A. b. nevadensis) that breed in bioclimatically diverse ecoregions in western North America. Overall, mtDNA and morphology are congruent with subspecies, ecoregion and bioclimatic niche. Niche divergence, rather than niche conservatism, accompanied by phenotypic adaptation, is associated with lineage diversification between subspecies. This diversification has occurred with and without physical barriers or accompanying genetic divergence. Populations of A. b. canescens are divided by a montane barrier into two bioclimatic regions (San Joaquin Valley, Mojave Desert), where they are indistinguishable phenotypically, but show distinctive genetic patterns. Although there is no physical barrier between A. b. canescens in the San Joaquin Valley and A. b. belli in the Coast Ranges, these populations occupy different bioclimatic niches and are phenotypically, but not genetically, diagnosable. Niche overlap is greatest between A. b. canescens from the Mojave Desert and A. b. nevadensis from the Great Basin, yet these subspecies maintain distinctive phenotypes and mtDNA, even in local secondary contact and sympatry. Palaeoclimatic niche models for the Last Glacial Maximum (c. 21 000 bp) and the Last Interglacial (c. 120 000 bp) suggest that ecoregionally distinct populations of Artemisiospiza belli experienced different Pleistocene range fluctuations and glacial refugia, with temporal niche conservatism. Populations probably reached their current distributions as favourable climates and habitats expanded after the last glaciation. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••–••.

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“…Hoekstra et al ., ; Mullen et al ., ) and lizards (e.g. Brehm et al ., ; Rosenblum, Hickerson & Moritz, ).…”

Section: Discussionmentioning

confidence: 98%

The role of niche divergence and phenotypic adaptation in promoting lineage diversification in the Sage Sparrow (Artemisiospiza belli, Aves: Emberizidae)

Cicero

Koo

2012

Biol J Linn Soc Lond

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“…Lastly, the breakdown of gene flow on islands allows adaptive changes to occur very rapidly compared to the accumulation of genetic divergence (Vitt et al. , 1997; Brehm et al. , 2001).…”

Section: Discussionmentioning

confidence: 99%

Mandibles and molars of the wood mouse, Apodemus sylvaticus (L.): integrated latitudinal pattern and mosaic insular evolution

Renaud¹,

Michaux²

2006

Journal of Biogeography

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International audienceAim The distinct nature of island populations has traditionally been attributed either to adaptation to particular insular conditions or to random genetic effects. In order to assess the relative importance of these two disparate processes, insular effects were addressed in the European wood mouse, Apodemus sylvaticus (Linnaeus, 1758). Location Wood mice from 33 localities on both mainland and various Atlantic and western Mediterranean islands were considered. This sampling covers only part of the latitudinal range of A. sylvaticus but included the two main genetic clades identified by previous studies. Islands encompass a range of geographical conditions (e.g. small islands fringing the continent through large and isolated ones). Methods The insular syndrome primarily invokes variations in body size, but ecological factors such as release from competition, niche widening and food availability should also influence other characters related to diet. In the present study, the morphology of the wood mice was quantified based on two characters involved in feeding: the size and shape of the mandibles and first upper molars. The size of the mandible is also a proxy for the body size of the animal. Patterns of morphological differentiation of both features were estimated using twodimensional outline analysis based on Fourier methods. Results Significant differences between mainland and island populations were observed in most cases for both the mandibles and molars. However, molars and mandibles displayed divergent patterns. Mandible shape diverged mostly on islands of intermediate remoteness and competition levels, whereas molars exhibited the greatest shape differentiation on small islands, such as Port-Cros and Porquerolles. A mosaic pattern was also displayed for size. Body and mandible size increased on Ibiza, but molar size remained similar to mainland populations. Mosaic patterns were, however, not apparent in the mainland populations. Congruent latitudinal variations were evident for the size and shape of both mandibles and molars. Main conclusions Mosaic evolution appears to characterize insular divergence. The molar seems to be more prone to change with reduced population size on small islands, whereas the mandible could be more sensitive to peculiar environmental conditions on large and remote islands

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“…2005). In addition, ecological factors influence genetic diversity (Brehem et al. 2001; Via 2002; Whiteley et al.…”

Section: Introductionmentioning

confidence: 99%

Population structure, genetic variation and morphological diversity in indigenous sheep of Ethiopia

et al. 2007

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We investigated genetic and morphological diversity and population structure of 14 traditional sheep populations originating from four ecological zones in Ethiopia (sub-alpine, wet highland, sub-humid lowland and arid lowland). All animals (n = 672) were genotyped for 17 microsatellite markers and scored for 12 morphological characters. The sheep were initially classified as fat-tailed (11 populations), thin-tailed (one population) and fat-rumped sheep (two populations). These classifications are thought to correspond to three consecutive introduction events of sheep from the Near-East into East Africa. For the 14 populations, allelic richness ranged from 5.87 to 7.51 and expected heterozygosity (H(E)) from 0.66 to 0.75. Genetic differentiations (F(ST) values) between all pairs of populations, except between sub-alpine populations, were significantly different from zero (P < 0.001). Cluster analysis of morphological characters and a dendrogram constructed from genetic distances were broadly consistent with the classification into fat-tailed, thin-tailed and fat-rumped sheep. Bayesian cluster analysis using microsatellite markers indicated that there has been further genetic differentiation after the initial introduction of sheep into Ethiopia. Investigation of factors associated with genetic variation showed that an isolation-by-distance model, independently of other factors, explained most of the observed genetic variation. We also obtained a strong indication of adaptive divergence in morphological characters, patterns of morphological variation being highly associated with ecology even when the effect of neutral genetic divergence (F(ST)) was parcelled out in partial Mantel tests. Using a combination of F(ST) values, Bayesian clustering analysis and morphological divergence, we propose a classification of Ethiopian sheep into six breed groups and nine breeds.

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Lack of congruence between morphometric evolution and genetic differentiation suggests a recent dispersal and local habitat adaptation of the Madeiran lizard Lacerta dugesii

Cited by 14 publications

References 26 publications

The role of niche divergence and phenotypic adaptation in promoting lineage diversification in the Sage Sparrow (Artemisiospiza belli, Aves: Emberizidae)

The role of niche divergence and phenotypic adaptation in promoting lineage diversification in the Sage Sparrow (Artemisiospiza belli, Aves: Emberizidae)

Mandibles and molars of the wood mouse, Apodemus sylvaticus (L.): integrated latitudinal pattern and mosaic insular evolution

Population structure, genetic variation and morphological diversity in indigenous sheep of Ethiopia

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