Maddock, ST;
Nussbaum, RA;
Day, JJ;
Latta, L;
Miller, M;
Fisk, DL;
Wilkinson, M;
... Pfrender, ME; + view all
(2020)
The roles of vicariance and isolation by distance in shaping biotic diversification across an ancient archipelago: evidence from a Seychelles caecilian amphibian.
BMC Evolutionary Biology
, 20
(1)
, Article 110. 10.1186/s12862-020-01673-w.
Preview |
Text
The roles of vicariance and isolation by distance in shaping biotic diversification across an ancient archipelago evidence f.pdf - Published Version Download (1MB) | Preview |
Abstract
Background: Island systems offer excellent opportunities for studying the evolutionary histories of species by virtue of their restricted size and easily identifiable barriers to gene flow. However, most studies investigating evolutionary patterns and processes shaping biotic diversification have focused on more recent (emergent) rather than ancient oceanic archipelagos. Here, we focus on the granitic islands of the Seychelles, which are unusual among island systems because they have been isolated for a long time and are home to a monophyletic radiation of caecilian amphibians that has been separated from its extant sister lineage for ca. 65–62 Ma. We selected the most widespread Seychelles caecilian species, Hypogeophis rostratus, to investigate intraspecific morphological and genetic (mitochondrial and nuclear) variation across the archipelago (782 samples from nine islands) to identify patterns and test processes that shaped their evolutionary history within the Seychelles. Results: Overall a signal of strong geographic structuring with distinct northern- and southern-island clusters were identified across all datasets. We suggest that these distinct groups have been isolated for ca. 1.26 Ma years without subsequent migration between them. Populations from the somewhat geographically isolated island of Frégate showed contrasting relationships to other islands based on genetic and morphological data, clustering alternatively with northern-island (genetic) and southern-island (morphological) populations. Conclusions: Although variation in H. rostratus across the Seychelles is explained more by isolation-by-distance than by adaptation, the genetic-morphological incongruence for affinities of Frégate H. rostratus might be caused by local adaptation over-riding the signal from their vicariant history. Our findings highlight the need of integrative approaches to investigate fine-scale geographic structuring to uncover underlying diversity and to better understand evolutionary processes on ancient, continental islands.
| Type: | Article |
|---|---|
| Title: | The roles of vicariance and isolation by distance in shaping biotic diversification across an ancient archipelago: evidence from a Seychelles caecilian amphibian |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1186/s12862-020-01673-w |
| Publisher version: | https://doi.org/10.1186/s12862-020-01673-w |
| Language: | English |
| Additional information: | This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. |
| Keywords: | Science & Technology, Life Sciences & Biomedicine, Evolutionary Biology, Genetics & Heredity, Adaptation, AFLPs, Biogeography, Caecilian, Evolution, Islands, Morphology, SPP. SQUAMATA SCINCIDAE, POPULATION-STRUCTURE, GYMNOPHIONA INDOTYPHLIDAE, GENETIC DIVERSITY, INDIAN-OCEAN, EVOLUTION, ISLAND, HISTORY, DIFFERENTIATION, SELECTION |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Genetics, Evolution and Environment |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10116556 |
Archive Staff Only
 |
View Item |
