tailieunhanh - Strong reproductive barriers in a narrow hybrid zone of West-Mediterranean green toads (Bufo viridis subgroup) with Plio-Pleistocene divergence

Research shows that sensational news stories as well as popular romance novels often feature themes related to important topics in evolutionary psychology. In the first of four studies described in this paper we examined the song lyrics from three Billboard charts: Country, Pop, and R&B. A content analysis of the lyrics revealed 18 reproductive themes that read like an outline for a course in evolutionary psychology. Approximately 92% of the 174 songs that made it into the Top Ten in 2009 contained one or more reproductive messages, with an average of reproductive. | Colliard et al. BMC Evolutionary Biology 2010 10 232 http 1471-2148 10 232 BMC Evolutionary Biology RESEARCH ARTICLE Open Access Strong reproductive barriers in a narrow hybrid zone of West-Mediterranean green toads Bufo viridis subgroup with Plio-Pleistocene divergence 1 2 3 2 1 1 Caroline Colliard Alessandra Sicilia Giuseppe Fabrizio Turrisi Marco Arculeo Nicolas Perrin Matthias Stock Abstract Background One key question in evolutionary biology deals with the mode and rate at which reproductive isolation accumulates during allopatric speciation. Little is known about secondary contacts of recently diverged anuran species. Here we conduct a multi-locus field study to investigate a contact zone between two lineages of green toads with an estimated divergence time of My and report results from preliminary experimental crosses. Results The Sicilian endemic Bufo siculus and the Italian mainland-origin B. balearicus form a narrow hybrid zone east of Mt. Etna. Despite bidirectional mtDNA introgression over a ca. 40 km North-South cline no F1 hybrids could be found and nuclear genomes display almost no admixture. Populations from each side of the contact zone showed depressed genetic diversity and very strong differentiation FST . Preliminary experimental crosses point to a slightly reduced fitness in F1 hybrids a strong hybrid breakdown in backcrossed offspring F1 x parental with very few reaching metamorphosis and a complete and early mortality in F2 F1 x F1 . Conclusion Genetic patterns at the contact zone are molded by drift and selection. Local effective sizes are reduced by the geography and history of the contact zone B. balearicus populations being at the front wave of a recent expansion late Pleistocene . Selection against hybrids likely results from intrinsic genomic causes disruption of coadapted sets of genes in backcrosses and F2-hybrids possibly reinforced by local adaptation the ranges of the two taxa roughly coincide with .

• Sức khỏe phụ nữ
• Model Selection Tests
• Stem Cell
• Novel Pathogenesis
• Pathogenesis of Endometriosis
• Green Tea
• Tea for Endometriosis
• Artificial intelligence
• Decision making
• Machine learning
• Model selection
• Philosophy of probability
• Tests of stationarity