A Combination of Divergence and Conservatism in the Niche Evolution of the Moorish Gecko, Tarentola mauritanica (Gekkota: Phyllodactylidae)
May
A Combination of Divergence and Conservatism in the Niche Evolution of the Moorish Gecko, Tarentola mauritanica (Gekkota: Phyllodactylidae)
Catarina Rato 0 1
David James Harris 0 1
Ana Perera 0 1
Silvia B. Carvalho 0 1
Miguel A. Carretero 0 1
Dennis Rdder 0 1
0 1 CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto , Campus Agrario de Vairao, Rua Padre Armando Quintas, Vairao, Vila do Conde, Portugal, 2 Zoologisches Forschungsmuseum Alexander Koenig, Bonn , Germany
1 Academic Editor: Stefan Lotters, Trier University , GERMANY
The quantification of realized niche overlap and the integration of species distribution models (SDMs) with calibrated phylogenies to study niche evolution are becoming not only powerful tools to understand speciation events, but can also be used as proxies regarding the delimitation of cryptic species. We applied these techniques in order to unravel how the fundamental niche evolved during cladogenesis within the Tarentola mauritanica species-complex. Our results suggest that diversification within this complex, during the Miocene and Pleistocene, is associated with both niche divergence and niche conservatism, with a pattern that varies depending on whether the variables involved are related to the mean or seasonality of temperature and humidity. Moreover, climatic variables related to humidity and temperature seasonality were involved in the niche shift and genetic diversification of the European/North African clade during the Pleistocene and in its maintenance in a fundamental niche distinct from that of the remaining members of the group. This study further highlights the need for a taxonomic revision of the T. mauritanica species-complex.
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Funding: Both CR and SBC are funded through a
Post-Doctoral grant (SFRH/BPD/92343/2013 and
SFRH/BPD/74423/2010, respectively) and AP by an
IF contract (IF/01257/2012) supported by the
Fundao para a Cincia e a Tecnologia (FCT) under
the Programa Operacional Potencial Humano
Quadro de Referncia Estratgico Nacional funds
from the European Social Fund and Portuguese
Ministrio da Educao e Cincia. DJH was
supported by the Project Genomics and Evolutionary
Speciation by natural selection occurs mainly through two distinct mechanisms;
mutationorder and ecological speciation [1,2,3] (Fig 1). Mutation-order speciation occurs when distinct
advantageous or neutral mutations are fixed by chance between different populations/entities,
while these are under similar ecological conditions or selective pressures [1,3]. The fixation of
such mutations by drift, reduces the fitness of hybrids over evolutionary time scales [4]. On the
other hand, ecological speciation refers to the evolution of reproductive isolation between
species primarily by differential adaptation to distinct environmental or ecological conditions
[5,6,7]. In this context, natural selection acts as a divergent mechanism driving to fixation
Biology, co-financed by North Portugal Regional
Operational Programme 2007/2013 (ON.2 O Novo
Norte), under the National Strategic Reference
Framework (NSRF), through the European Regional
Development Fund (ERDF). Research was funded by
FEDER funds through the Operational Programme
for Competitiveness Factors - COMPETE and by
National Funds through FCT - under the projects
PTDC/BIA-BEC/105327/2008 and
FCOMP-01-0124FEDER-008970 (to AP) and PTDC/BIA-BIC/118624/
2010 and FCOMP-01-0124-FEDER-019676 (to
SBC). The funders had no role in study design, data
collection and analysis, decision to publish, or
preparation of the manuscript.
Competing Interests: The authors have declared
that no competing interests exist.
distinct advantageous mutations in each of the different environments [1,2]. Whether
ecological divergence may constitute the primary force inducing speciation or simply acts secondarily
after an interruption of gene flow due to other causes may be difficult to ascertain in practice
by monitoring the ecological traits of clades in a given phylogeny [1]. However, the appraisal of
ecological divergence can sometimes serve as a proxy to support species delimitation to
understand which ecologically associated factors led to speciation (e.g. [8,9,10,11,12]).
During ecological divergence, natural populations are subjected to different biotic and abiotic
factors, such as predation, competition, climate and food resource fluctuations [1,5], which may
lead to distinct evolutionary responses and patterns of climatic tolerances (reviewed in [13]) and
to the consequent evolution of organisms in new habitats (niche divergence) (e.g.
[8,14,15,16,17]). On the contrary, niche conservatism consists of the preservation of ecological
similarity among populations over time [18,19], being important in the classic model of
allopatric speciation, as it may limit adaptation to the ecological conditions at the geographic barrier
and promote genetic isolation and differentiation between vicariant populations (e.g.
[15,16,20,21]) (F (...truncated)