An integrative study of island diversification: Insights from the endemic Haemodracon geckos of the Socotra Archipelago

Tamar K., Simó-Riudalbas M., Garcia-Porta J., Santos X., Llorente G., Vasconcelos R., Carranza S. (2019) An integrative study of island diversification: Insights from the endemic Haemodracon geckos of the Socotra Archipelago. Molecular Phylogenetics and Evolution. 133: 166-175.
Link
Doi: 10.1016/j.ympev.2019.01.009

Abstract:

The Socotra Archipelago in the Arabian Sea is considered one of the most geo-politically isolated landforms on earth and a center of endemism. The archipelago is located at the western edge of the Indian Ocean and comprises four islands: Socotra, Darsa, Samha, and Abd al Kuri. Here we provide an integrative study on Haemodracon geckos, the sole genus of geckos strictly endemic to the archipelago. The sympatric distribution of Haemodracon riebeckii and H. trachyrhinus on Socotra Island provides a unique opportunity to explore evolutionary relationships and speciation patterns, examining the interplay between possible sympatric and allopatric scenarios. We used molecular data for phylogenetic inference, species delimitation analyses, and to infer the diversification timeframe. Multivariate statistics were used to analyze morphological data. Ecological comparisons were explored for macro-niches using species distribution models and observations were used for micro-habitat use. Haemodracon species exhibit great levels of intraspecific genetic diversity. Our calibration estimates revealed that Haemodracon diverged from its closest relative, the mainland genus Asaccus, in the Eocene, before the detachment of the archipelago. The two Haemodracon species diversified in situ on Socotra Island during the Middle Miocene, after the archipelago's isolation, into the two reciprocally monophyletic recognized species. Their divergence is associated mostly with remarkable body size differences and micro-habitat segregation, with low levels of climatic and body shape divergences within their sympatric distributions. These results display how ecological, sympatric speciation, and allopatric speciation followed by secondary contact, may both have varying roles at different evolutionary phases. © 2019 Elsevier Inc.

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Oldest skeleton of a fossil flying squirrel casts new light on the phylogeny of the group

Casanovas-Vilar I., Garcia-Porta J., Fortuny J., Sanisidro Ó., Prieto J., Querejeta M., Llácer S., Robles J.M., Bernardini F., Alba D.M. (2018) Oldest skeleton of a fossil flying squirrel casts new light on the phylogeny of the group. eLife. 7: 0-0.
Link
Doi: 10.7554/eLife.39270

Abstract:

Flying squirrels are the only group of gliding mammals with a remarkable diversity and wide geographical range. However, their evolutionary story is not well known. Thus far, identification of extinct flying squirrels has been exclusively based on dental features, which, contrary to certain postcranial characters, are not unique to them. Therefore, fossils attributed to this clade may indeed belong to other squirrel groups. Here we report the oldest fossil skeleton of a flying squirrel (11.6 Ma) that displays the gliding-related diagnostic features shared by extant forms and allows for a recalibration of the divergence time between tree and flying squirrels. Our phylogenetic analyses combining morphological and molecular data generally support older dates than previous molecular estimates (~23 Ma), being congruent with the inclusion of some of the earliest fossils (~36 Ma) into this clade. They also show that flying squirrels experienced little morphological change for almost 12 million years. © Casanovas-Vilar et al.

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Diversification in arid mountains: biogeography and cryptic diversity of Pristurus rupestris rupestris in Arabia

Garcia-Porta, J., Simó-Riudalbas, M., Robinson, M., Carranza, S. (2017) Diversification in arid mountains: biogeography and cryptic diversity of Pristurus rupestris rupestris in Arabia. Journal of Biogeography. 44: 1694-1704.
Link
Doi: 10.1111/jbi.12929

Abstract:

Transcriptomic and macroevolutionary evidence for phenotypic uncoupling between frog life history phases

Valero, K.C.W., Garcia-Porta, J., Rodríguez, A., Arias, M., Shah, A., Randrianiaina, R.D., Brown, J.L., Glaw, F., Amat, F., Künzel, S., Metzler, D., Isokpehi, R.D., Vences, M. (2017) Transcriptomic and macroevolutionary evidence for phenotypic uncoupling between frog life history phases. Nature Communications. 8: 0-0.
Link
Doi: 10.1038/ncomms15213

Abstract:

Testing the island effect on phenotypic diversification: Insights from the Hemidactylus geckos of the Socotra Archipelago

Garcia-Porta J., Šmíd J., Sol D., Fasola M., Carranza S. (2016) Testing the island effect on phenotypic diversification: Insights from the Hemidactylus geckos of the Socotra Archipelago. Scientific Reports. 6: 0-0.
Link
Doi: 10.1038/srep23729

Abstract:

Island colonization is often assumed to trigger extreme levels of phenotypic diversification. Yet, empirical evidence suggests that it does not always so. In this study we test this hypothesis using a completely sampled mainland-island system, the arid clade of Hemidactylus, a group of geckos mainly distributed across Africa, Arabia and the Socotra Archipelago. To such purpose, we generated a new molecular phylogeny of the group on which we mapped body size and head proportions. We then explored whether island and continental taxa shared the same morphospace and differed in their disparities and tempos of evolution. Insular species produced the most extreme sizes of the radiation, involving accelerated rates of evolution and higher disparities compared with most (but not all) of the continental groups. In contrast, head proportions exhibited constant evolutionary rates across the radiation and similar disparities in islands compared with the continent. These results, although generally consistent with the notion that islands promote high morphological disparity, reveal at the same time a complex scenario in which different traits may experience different evolutionary patterns in the same mainland-island system and continental groups do not always present low levels of morphological diversification compared to insular groups.

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Similar local, but different systemic, metabolomic responses of closely related pine subspecies to folivory by caterpillars of the processionary moth

Rivas-Ubach A., Sardans J., Hódar J.A., Garcia-Porta J., Guenther A., Oravec M., Urban O., Peñuelas J. (2015) Similar local, but different systemic, metabolomic responses of closely related pine subspecies to folivory by caterpillars of the processionary moth. Plant Biology. : 0-0.
Link
Doi: 10.1111/plb.12422

Abstract:

Plants respond locally and systemically to herbivore attack. Most of the research conducted on plant-herbivore relationships at element and molecular levels have focused on the elemental composition or/and certain molecular compounds or specific families of defence metabolites showing that herbivores tend to select plant individuals or species with higher nutrient concentrations and avoid those with higher levels of defence compounds. We performed stoichiometric and metabolomics, both local and systemic, analyses in two subspecies of Pinus sylvestris under attack from caterpillars of the pine processionary moth, an important pest in the Mediterranean Basin. Both pine subspecies responded locally to folivory mainly by increasing relative concentrations of terpenes and some phenolics. Systemic responses differed between pine subspecies, and most of the metabolites presented intermediate concentrations between those of the affected parts and unattacked trees. Our results support the hypothesis that foliar nutrient concentrations are not a key factor for plant selection by adult female processionary moths for oviposition, since folivory was not associated with any of the elements analysed. Phenolic compounds generally did not increase in the attacked trees, questioning the suggestion of induction of phenolics following folivory attack and the anti-feeding properties of phenolics. Herbivory attack produced a general systemic shift in pines, in both primary and secondary metabolism, which was less intense and chemically different from the local responses. Local pine responses were similar between pine subspecies, while systemic responses were more distant. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

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