GEOGRAPHIC VARIATION WITHIN AN ISLAND: UNIVARIATE AND MULTIVARIATE CONTOURING OF SCALATION, SIZE, AND SHAPE OF THE LIZARD<i>GALLOTIA GALLOTI</i>

Thorpe, Roger S.; Báez, Marcos

doi:10.1111/j.1558-5646.1987.tb05795.x

Cited by 53 publications

(6 citation statements)

References 34 publications

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“…The rejected allopatry hypotheses (1)(2)(3)(4) are also unlikely on other grounds. This hypothesis (6) has the highest and most significant partial correlation with the generalized pattern and all individual characters, except for the number of blue blotches.…”

Section: Research Articlesmentioning

confidence: 99%

Testing hypothesized causes of within-island geographic variation in the colour of lizards

Thorpe

Brown

1989

Experientia

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Within the island of Tenerife the lizard Gallotia galloti shows geographic variation in a range of features, most notably the colour pattern of breeding males. Numerous (7) specific causal hypotheses, both phylogenetic and ecogenetic, are proposed or plausible for this geographic variation and these are simultaneously tested against the observed multivariate pattern. The hypotheses based on the divergence in allopatry (e.g. the secondary contact of populations from the precursor islands of Anaga and Teno and the separation of high-and low-altitude populations by encircling cloud) are rejected. The hypothesis that the pattern is caused by topographically determined climatic differences within the island is not rejected. The climate may influence the balance between selection for signalling colouration for sexual/territorial purposes and natural selection for crypsis.

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Section: Research Articlesmentioning

confidence: 99%

Testing hypothesized causes of within-island geographic variation in the colour of lizards

Thorpe

Brown

1989

Experientia

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“…The latter aspect is important because due to sexual differences in reproductive and ecological roles, some factors can affect one sex more than the other. As a result, geographic patterns in body size may differ markedly between males and females (Herczeg, Gonda, & Merilä, 2010;Pearson, Shine, & Williams, 2002;Roitberg et al, 2015;Saino & De Bernardi, 1994;Thorpe & Baez, 1987).…”

Section: Introductionmentioning

confidence: 99%

Variation in body size and sexual size dimorphism in the most widely ranging lizard: testing the effects of reproductive mode and climate

Roitberg

Orlova

Булахова

et al. 2020

Ecology and Evolution

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Reproductive mode, ancestry, and climate are hypothesized to determine body size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species' range, we analyzed how sex‐specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south‐western France) exhibited a smaller female size and less female‐biased SSD than those of the western viviparous (France to Eastern Europe) and the eastern viviparous (Eastern Europe to Far East) lineages; this pattern persisted even after controlling for climatic effects. The phenotypic response to seasonality was complex: across the lineages, as well as within the eastern viviparous lineage, female size and SSD increase with increasing seasonality, whereas the western viviparous lineage followed the opposing trends. Altogether, viviparous populations seem to follow a saw‐tooth geographic cline, which might reflect the nonmonotonic relationship of body size at maturity in females with the length of activity season. This relationship is predicted to arise in perennial ectotherms as a response to environmental constraints caused by seasonality of growth and reproduction. The SSD allometry followed the converse of Rensch's rule, a rare pattern for amniotes. Our results provide the first evidence of opposing body size—climate relationships in intraspecific units.

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“…Previous studies indicated that variation in scale numbers is often correlated with climate; hotter and drier conditions may favor either fewer but larger scales [140], [141] or a greater number of smaller scales [142], [143]. Sanders et al [144] studied variation in scalation in nocturnal and arboreal Trimeresurus snakes, which also show an increase in scale numbers in hotter and drier climates.…”

Section: Resultsmentioning

confidence: 99%

Island Evolution and Systematic Revision of Comoran Snakes: Why and When Subspecies Still Make Sense

2012

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Species delimitation and species concepts have been a matter of debate among biodiversity researchers in the last decades, resulting in integrative taxonomy approaches and the use of modern species concepts, such as the phylogenetic, evolutionary or general lineage species concepts. The discussion of subspecies status and concepts has been addressed much less extensively, with some researchers completely refraining from recognizing subspecies. However, allopatric insular populations that are particularly differentiated have traditionally been assigned subspecies status. We studied the molecular phylogeny and morphology of endemic Comoran tree snakes of the genus Lycodryas. Taking an integrative taxonomic approach, we used the concept of independent lines of evidence to discriminate between evidence for specific and subspecific status. Molecular (mtDNA) and morphological data provided sufficient evidence to support four different taxa within Comoran Lycodryas. In a revision of this group, we propose two species, each with two subspecies. We present a discussion of the strong sexual dichromatism unique to Comoran Lycodryas within the genus and related genera that may be explained by sexual selection in combination with the absence of major predators. Then, we discuss the effects of insular evolution and the “island rule” on morphological traits in Comoran Lycodryas and in Liophidium mayottensis, another snake endemic to the Comoros. The absence of larger-bodied snakes may have promoted an increase in body size and the number of dorsal scale rows in these species. Finally, we discuss the subspecies concept, its applications and its significance for integrative taxonomy and for limiting taxonomic inflation. We emphasize that taxon descriptions should be based on an integrative approach using several lines of evidence, preferably in combination with statements on the underlying species concepts or operational criteria, to increase the objectivity and comparability of descriptions.

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GEOGRAPHIC VARIATION WITHIN AN ISLAND: UNIVARIATE AND MULTIVARIATE CONTOURING OF SCALATION, SIZE, AND SHAPE OF THE LIZARDGALLOTIA GALLOTI

Cited by 53 publications

References 34 publications

Testing hypothesized causes of within-island geographic variation in the colour of lizards

Testing hypothesized causes of within-island geographic variation in the colour of lizards

Variation in body size and sexual size dimorphism in the most widely ranging lizard: testing the effects of reproductive mode and climate

Island Evolution and Systematic Revision of Comoran Snakes: Why and When Subspecies Still Make Sense

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