The dynamics of genetic and morphological variation on volcanic islands

Abstract

Oceanic archipelagos of volcanic origin have been important in the study of evolution because they provide repeated natural experiments allowing rigorous tests of evolutionary hypotheses. Ongoing volcanism on these islands may, however, affect the evolutionary diversification of species. Analysis of population structure and phylogeographic patterns in island populations can provide insight into evolutionary dynamics on volcanic islands. We analysed genetic and morphological variation in the gecko Tarentola boettgeri on the island of Gran Canaria and compared it with Tarentola delalandii on Tenerife, a neighbouring volcanic island of similar age but distinctly different geological past. Intraspecific divergence of mitochondrial haplotypes indicates long-term persistence of Tarentola on each island, with a phylogeographic signal left by older volcanic events. More recent volcanic eruptions (approximately 0.2 million years ago on Tenerife, approximately 2.2 million years ago on Gran Canaria) have left a signature of population expansion in the population genetic structure, the strength of which depends on the time since the last major volcanic eruption on each island. While these stochastic events have left traces in morphological variation in Tenerife, in Gran Canaria geographical variation was solely associated with environmental variables. This suggests that historically caused patterns in morphology may be overwritten by natural selection within 2 million years.

Colonization of the Aeolian Islands byPimelia rugulosa rugulosaGermar, 1824 (Coleoptera: Tenebrionidae) inferred from the genetic structure of populations: geological and environmental relations

“…The observed high level of fragmentation can be further interpreted in terms of the variegated geological history of the archipelago (Gübitz et al, 2005;Bloor et al, 2008). Volcanism, by determining the independent emergence of different islands in succession over approximately the last 400 kyr, shaped an extremely fragmented environment, which promoted the differentiation of separate lineages of P. r. rugulosa in each island.…”

“…Volcanic islands are dynamic environments that have undergone changes in size and shape during their formation, leaving characteristic signatures in the genetic and morphological variation of local populations (Carson & Templeton, 1984;Carson, Lockwood & Craddock, 1990;Beheregaray et al, 2003;Gübitz et al, 2005;Bloor, Kemp & Brown, 2008). Furthermore, studies conducted on several species provide evidence that volcanism may affect within-island cladogenesis and genetic diversity (Thorpe, Black & Malhotra, 1996;Pestano & Brown, 1999;Brown, Campos-Delgado & Pestano, 2000) and that massive volcanic events may lead to a reduction in both genetic and biological diversity (Emerson & Oromi, 2000;Contreras-Diaz et al, 2003;Emerson, 2003).…”

“…Archipelagos of volcanic origin have been intensely studied as they provide ideal sites for testing evolutionary hypotheses (Gübitz, Roger & Malhotra, 2005). Volcanic islands are dynamic environments that have undergone changes in size and shape during their formation, leaving characteristic signatures in the genetic and morphological variation of local populations (Carson & Templeton, 1984;Carson, Lockwood & Craddock, 1990;Beheregaray et al, 2003;Gübitz et al, 2005;Bloor, Kemp & Brown, 2008).…”

Pleistocene climatic cycling drives intra‐specific diversification in the intermediate horseshoe bat (Rhinolophus affinis) in Southern China

“…2003; Vandergast et al. 2004; Gübitz et al. 2005), which occurred on Hainan during the early Pleistocene (Long et al.…”

Historical volcanism and within-island genetic divergence in the Tenerife skink (Chalcides viridanus)

“…2) as this contained many individuals (n=43) allowing examination of a reasonable number of temporal groups (five were used and reported here, but analyses were also performed with between 2- appears quite similar to that in lizards on the neighbouring islands of Gran Canaria (Gübitz et al, 2005; and Lanzarote (Bloor et al, 2008) and also to giant tortoises on the Galápagos (Beheregaray et al, 2003).…”