Forces driving the divergence of Carex (Cyperaceae) lineages: the role of the biotic component
ID: 613 / 302
Proposed Symposium Title: Forces driving the divergence of Carex (Cyperaceae) lineages: the role of the biotic component
Carmen Benítez-Benítez1, Pedro Jiménez-Mejías2, Juan Antonio Calleja-Alarcón3, María Sanz-Arnal2, Pablo Vargas4, Francisco Lara3, Roberto Garilleti5, Santiago Martín-Bravo2, Marcial Escudero1, Mario Fernández-Mazuecos3, Joaquín Calatayud6#, Nagore Medina3#
Affiliations: 1 Department of Plant Biology and Ecology, Universidad de Sevilla, Seville, Spain 2 Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain 3 Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain 4 Real Jardín Botánico de Madrid, Madrid, Spain 5 Department of Botany and Geology, Universidad de Valencia, Valencia, Spain 6 Department of Biology and Geology, Physics and Inorganic Chemistry, Universidad Rey Juan Carlos, Madrid, Spain
Divergence between lineages and speciation may be attributed to both geographic isolation and adaptive ecological differentiation. Carex elata and C. reuteriana are two closely related species with very similar habit ecological requirements, inhabiting river shores at medium-low altitudes, that display an allopatric distribution within the Iberian Peninsula. They conform an ideal system to study the relative importance of geographical versus ecological factors in differentiation and speciation. We employed a multidisciplinary approach integrating abiotic, biotic and geographical factors, and genomic data (genotyping-by-sequencing) to infer the relative role of different evolutionary drivers. Abiotic factors were assessed based on 38 bioclimatic variables. We characterised biotic factors using the community of co-occurring plant species as a proxy containing real presence and absence data for vascular plant taxa (using 1536 vegetation inventories). Geographical factors were evaluated with a distance matrix based on geographic coordinates. We used regularized generalized linear models to determine which variables contribute more to explain the observed allopatric distribution pattern. Furthermore, we examined the relationships between genetic distances (from SNPs) and abiotic, biotic and geographical factors. The genomic analysis revealed a clear geographic structure of the taxa. Interestingly, their distributions are better predicted by the presence of other species within their respective communities than by abiotic or geographical factors. This suggests that biotic factors have played an important role in the divergence of these taxa or act as a proxy for other unaccounted ecological factors. In addition, inter-population genetic distances of each taxon are significantly associated with all aforementioned factors, albeit with varying degrees of influence. However, biotic distances alone explain the highest proportion of genetic distance variance within C. elata, whereas abiotic or geographical factors have a greater effect in C. reuteriana. This study contributes to a deeper understanding of the evolutionary processes shaping the distribution and population dynamics of species.