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Sergio Castellano

Publications and source records attributed to Sergio Castellano.

3 recordsLinked to original sources

Reconciling sexual selection to species recognition: a process-based model of mating decision.

Mating signals often encode information important for both species recognition and mate quality assessment and endure selection pressures that combine both stabilizing and directional components. Here, we present a family of models of mate preference for multiple-message signals. Our models are process based rather than purely normative, they assume the existence of one (or more) "utility function" that order signals along a scale of perceived appropriateness, and interpret preferences either as the differential probability of signals recognition or as the combined effect of differential recognition and direct comparison between signal alternatives. These models show the critical role played by the proximate mechanisms of information processing in influencing the ultimate function of female mate choice. They show that if preferences are an emergent property of the way animals recognize signals then species recognition and mate quality assessment are expected to constrain each other severely and to limit the overall discrimination power of the system. In contrast, if preferences result from two computational processes, recognition and comparison, the constraining effects of species recognition and mate quality assessment are sensibly reduced. In these cases, females may improve discrimination in mate quality by adopting permissive recognition rules and limiting the risks of heterospecific mating.

Animals↗

Evidence for chromosome and Pst I satellite DNA family evolutionary stasis in the Bufo viridis group (Amphibia, Anura).

The West Palearctic green toads, Bufo viridis , represent a species complex. Apart from tetraploid populations, which form at least one separate species, evidence exists for relevant differentiation among diploid populations. We present the results of a chromosomal (C-, Ag-NOR-, Replication pattern, DAPI and CMA3 banding) and molecular study (isolation and characterization of a satellite DNA family) carried out on a number of Central Asian, European and North African populations. For comparative purposes, our molecular analysis was also extended to specimens of three additional Bufo species (B. bufo, B. mauritanicus and B. cf. regularis ), as well as two rare African bufonids (Werneria mertensis and Wolterstoffina sp.). Our results demonstrate a remarkable karyological and molecular evolutionary stasis in the Bufo viridis complex. In fact, all chromatinic markers showed the same pattern and/or composition in all specimens, independently of their origin and ploidy levels. Even the NOR loci were invariably two and located on the telomeric regions of two chromosomes of the sixth pair, or quartet. Furthermore, very similar patterns of genomic hybridization of a monomeric unit of the Pst I satellite DNA family (named pBv) were observed in all diploid and tetraploid populations, as well as in B. bufo and B. mauritanicus . Finally, pBv hybridizes with monomeric units of Pst I satellite DNA in all species studied, including Werneria and Wolterstorffina, which are thought to have separated from Bufo as early as in the Mesozoic.

Animals↗

Is the partial Mantel test inadequate?

A publication by Raufaste and Rousset (2001) questioned the effectiveness of the partial Mantel test, a nonparametric statistical test for association among three distance matrices. By repeated simulations, we calculated the cumulative density functions of the null-hypothesis probability of no correlation, within an explicit model of causal relationships. Results do not support the criticism: in conditions of moderate correlation between the independent matrices, the actual error rate is closely associated to the intended type-I error alpha.

Computer Simulation↗