Abstract
The combination of niche modelling and landscape genetics (genomics) helps to disentangle processes that have shaped population structure in the evolutionary past and presence of species. Herein, we integrate a comprehensive genomic dataset with ecological parameters and niche modelling for the threatened Kaiser’s newt, a newt species adapted to mountain spring-ponds in Iran. Genomic analysis suggests the existence of two highly differentiated clades North and South of the Dez River. Genetic variation between the two clades (76.62%) was much greater than within clades (16.25%), suggesting that the Dez River prevented gene flow. River disconnectivity, followed by geographic distance, contributed mostly to genetic differentiation between populations. Environmental niche and landscape resistance had no significant influence. Though a significant difference between climatic niches occupied by each clade at the landscape-scale, habitat niches at the local-scale were equivalent. ‘Niche similarity analysis’ supported niche conservatism between the two clades despite the southward shift in the climatic niche of the Southern clade. Accordingly, populations of different clades may occupy different climatic niches within their ancestral niche. Our results indicate that the change of climatic conditions of geographically and genetically separated populations does not necessarily result in the shift of an ecological niche.
Highlights
Landscape characteristics influence functional connectivity of habitats and affect migration and gene flow of individuals among populations[1]
Using de novo assembly on reads obtained from a ddRAD protocol, we recovered a total of 26,746 loci of an average length of 115 bp, each of them being present in at least 28 individuals of N. kaiseri from 16 localities (Fig. 1)
This tree shows a structure within N. kaiseri that is consistent with the previous study on a segment of the mitochondrial DNA24, populations are split into two monophyletic groups, which are geographically separated by the Dez River (Fig. 1)
Summary
Landscape characteristics influence functional connectivity of habitats and affect migration and gene flow of individuals among populations[1]. Genetic divergence at the intraspecific level is mainly the result of limited gene flow among allopatric populations or lineages If these lineages use different components of the environmental space, this differentiation will result in a ‘niche divergence’ pattern[12]. Populations of N. kaiseri are facing a heterogeneous mountainous landscape with diverse climatic conditions ranging from wet to dry that is disconnected by two main rivers, Dez and Karoon. This is in contrast to the remaining more northerly distributed species (N. strauchii, N. crocatus, N. barrani and N. derjugini), which occupy more homogenous mountainous habitats and reproduce in streams. In order to obtain a more complete understanding of both genetic structure and the underlying processes shaping it, the analysis of an extensive multi-locus dataset for N. kaiseri is crucial to inform future conservation measures
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
