Biology subjects

Carvajal-Rodriguez, A.

Publications and source records attributed to Carvajal-Rodriguez, A..

4 recordsLinked to original sources

bioRxiv2018

Multi-model inference of mate choice effects from an information theoretic approach

Non-random mating has a significant impact on the evolution of organisms. Here, I developed a modelling framework for discrete traits (with any number of phenotypes) to explore different models connecting the non-random mating causes (intra sexual competition and/or mate choice) and their consequences (sexual selection and/or assortative mating). I derived the formulas for the maximum likelihood estimates of each model and used information criteria for performing multimodel inference. Simulation results showed a good performance of both model selection and parameter estimation. The methodology was applied to data from Galician Littorina saxatilis ecotypes, to show that the mating pattern is better described by models with two parameters that involve both mate choice and intrasexual competition, generating positive assortative mating plus female sexual selection. As far as I know, this is the first standardized methodology for model selection and multimodel inference of mating parameters for discrete traits. The advantages of this framework include the ability of setting up models from which the parameters connect causes, as intrasexual competition and mate choice, with their outcome in the form of data patterns of sexual selection and assortative mating. For some models, the parameters may have a double effect i.e. they cause both kind of patterns, while for others models there are separated parameters for one kind of pattern or another. The full methodology was implemented in a software called InfoMating (available at http://acraaj.webs6.uvigo.es/InfoMating/Infomating.htm).

evolutionary biology↗

bioRxiv2018

A generalization of the informational view of non-random mating: Models with variable population frequencies

Mate choice may generate non-random mating patterns. It has been recently shown that the mating distribution caused by mate choice can be expressed as a gain in information with respect to random mating. In that model, the population phenotypic frequencies were assumed as constant during the breeding season. In the present work such restriction was relaxed to consider different encounter-mating processes in which the population frequencies of available individuals change over mating rounds. As with the constant case, here we describe the change in the mating phenotypes by the flow of information with respect to random mating. This information can be partitioned into sexual selection, sexual isolation and a mixed effect. Likewise, the pairwise statistics for total change, sexual selection and sexual isolation are generalized for variable population frequencies.\n\nThe new tests had more power for the detection of the effects of non-random mating when the population frequencies vary during the breeding season. The differences in power were high for sexual selection but slight for sexual isolation scenarios. However, the application of the new formulas require the estimation of frequencies at each mating round. Therefore, choosing one or another type of statistics would depend on the biological scenario as well as in the availability and easiness to split the sampling in more than one mating round.

evolutionary biology↗

bioRxiv2017

MatSim: Monte Carlo simulation for the generation of mating tables

In species with sexual reproduction, the mating pattern is a meaningful element for understanding evolutionary and speciation processes. Given a mating pool where individuals can encounter each other randomly, the individual mating preferences would define the mating frequencies in the population. However, in every mating process we can distinguish two different steps. First, the encounter between partners. Second, the actual mating once the encounter has occurred. Yet, we cannot always assume that the observed population patterns accurately reflect the individuals preferences. In some scenarios the individuals may have difficulties to achieve their preferred matings, such as in monogamous species with low population size, where the mating process is similar to a sampling without replacement. In the latter, the encounter process will introduce some noise that may disconnect the individual preferences from the obtained mating pattern. Actually, the difference between the mating pattern observed in a population and the mating preferences of the individuals have been shown by different modeling scenarios.\n\nHere I present a program that simulates the mating process for both discrete and continuous traits, under different encounter models and individual preferences, including effects as time dependence and aging. The utility of the software is demonstrated by replicating and extending, a recent study that showed how patterns of positive assortative mating, or marriage in human societies, may arise from non-assortative individual preferences. The previous result is confirmed and is shown to be caused by the marriage among the \"ugliest\" and oldest individuals, who after many attempts were finally able to mate among themselves. In fact, I show that the assortative pattern vanishes if an aging process prevents these individuals from mating altogether. The software MateSim is available jointly with the users manual, at http://acraaj.webs.uvigo.es/MateSim/matesim.htm

evolutionary biology↗

bioRxiv2016

Non-random mating and information theory

In this work, mate choice is modeled by means of the abstract concept of mutual mating propensity. This only assumes that different type of couples can have different mating success. The model is adequate for any population where mating occurs among distinct types. There is no extra assumption about particular mating scheme or preference model. The concept of mutual mating propensity permits to express the observed change in the mating phenotypes as the gain in information with respect to random mating. The obtained expression is a form of the Price equation in which the mapping between ancestral and descendant population is substituted by a mapping between random mating and non random mating population.\n\nAt the same time, this framework provides the connection between mate choice and the exact mathematical partition of the choice effects, namely sexual isolation, sexual selection and a mixed effect. The sexual selection component is the sum of the intra-sexual male and female selection.\n\nThe proposed framework helps to unveil previously hidden invariants. For example, if the mutual preference between partner types is multiplicative there is no sexual isolation (inter-sexual selection) effect on the frequencies, i.e. the only possible effect of mate choice is intra-sexual selection. On the contrary, whatever the contribution of each partner to the mutual preference, if it comes as a non-multiplicative factor, there is at least an inter-sexual selection detectable effect.\n\nThis new view over the mate choice problem, permits to develop general mating propensity models and to make predictions of the mate choice effects that may emerge from such models. This possibility opens up the way for setting a general theory of model fitting and multimodel inference for mate choice.\n\nThus, it is suggested that the proposed framework, by describing mate choice as the flow of information due to non-random mating, provides a new important setting for exploring different mating models and their consequences.

evolutionary biology↗