Browsing by Autor "Camilo Salazar"

Now showing 1 - 4 of 4

A neotropical polymorphic damselfly shows poor congruence between genetic and traditional morphological characters in Odonata
(Elsevier BV, 2010) Melissa Sánchez Herrera; Emilio Realpe; Camilo Salazar
Multiple sources of reproductive isolation in a bimodal butterfly hybrid zone
(Oxford University Press, 2010) ASTRID G. MUÑOZ; Camilo Salazar; Juan Manuel Gonzales Castano; Chris D. Jiggins; Mauricio Linares
An important evolutionary question concerns whether one or many barriers are involved in the early stages of speciation. We examine pre- and post-zygotic reproductive barriers between two species of butterflies (Heliconius erato chestertonii and H. e. venus) separated by a bimodal hybrid zone in the Cauca Valley, Colombia. We show that there is both strong pre- and post-mating reproductive isolation, together leading to a 98% reduction in gene flow between the species. Pre-mating isolation plays a primary role, contributing strongly to this isolation (87%), similar to previous examples in Heliconius. Post-mating isolation was also strong, with absence of Haldane's rule, but an asymmetric reduction in fertility (< 11%) in inter-specific crosses depending on maternal genotype. In summary, this is one of the first examples of post-zygotic reproductive isolation playing a significant role in early stages of parapatric speciation in Heliconius and demonstrates the importance of multiple barriers to gene flow in the speciation process.
The Andes as a semi-permeable geographical barrier: genetic connectivity between structured populations in a colorful and widespread spider
(2024) Fabian C. Salgado‐Roa; Carolina Pardo‐Díaz; Nicol Rueda‐M; Diego F. Cisneros‐Heredia; Eloisa Lasso; Camilo Salazar
Geographic barriers, such as mountain ranges, impede genetic exchange among populations, promoting diversification and speciation. The effectiveness of these barriers in limiting gene flow varies between lineages due to each species’ unique dispersal modes and capacities. Our understanding of how the Andes orogeny contributes to species diversification comes from well-studied vertebrates and a few insects, neglecting organisms unable to fly or walk long distances. Additionally, although the Andean altitude is usually assumed to be the driver of diversification, it is not often formally tested. This limits our understanding of how landscape changes, particularly altitude, influence population structure. Some arachnids, such as the colorful spider Gasteracantha cancriformis have been hypothesized to disperse long distances via ballooning (i.e., using their silk to interact with the wind). Still, we do not know how the environment and geography shape its genetic diversity. To address this question, we sampled thousands of loci across the distribution of this spider and implemented population genetics, phylogenetic, and landscape genetic analyses. We identified two genetically distinct groups structured by the Central Andes and a third less structured group in the northern Andes that shares ancestry with the previous two. This structure is largely explained by the elevation along the Andes, which decreases in some regions, facilitating cross-Andean dispersal and gene flow. Our findings support that elevation in the Andes plays a major role in structuring populations in South America, but the strength of this barrier can be defeated by organisms with long-distance dispersal modes together with altitudinal depressions
Two sisters in the same dress: Heliconius cryptic species
(Springer Science+Business Media, 2008) Nathalia Giraldo; Camilo Salazar; Chris D. Jiggins; Eldredge Bermingham; Mauricio Linares
We hypothesize that these species might have resulted from recent convergence in colour pattern, perhaps facilitated by hybrid introgression of wing pattern genes.