784 resultados para Mutual Mate Choice
Resumo:
A previous genome-wide association study (GWAS) of more than 100,000 individuals identified molecular-genetic predictors of educational attainment. We undertook in-depth life-course investigation of the polygenic score derived from this GWAS using the four-decade Dunedin Study (N = 918). There were five main findings. First, polygenic scores predicted adult economic outcomes even after accounting for educational attainments. Second, genes and environments were correlated: Children with higher polygenic scores were born into better-off homes. Third, children's polygenic scores predicted their adult outcomes even when analyses accounted for their social-class origins; social-mobility analysis showed that children with higher polygenic scores were more upwardly mobile than children with lower scores. Fourth, polygenic scores predicted behavior across the life course, from early acquisition of speech and reading skills through geographic mobility and mate choice and on to financial planning for retirement. Fifth, polygenic-score associations were mediated by psychological characteristics, including intelligence, self-control, and interpersonal skill. Effect sizes were small. Factors connecting DNA sequence with life outcomes may provide targets for interventions to promote population-wide positive development.
Resumo:
Mate choice is a primary mechanism driving the evolution of sexually selected traits such as elabo-rate displays and ornaments. In a majority of taxa studied to date, females are seen to actively sampleand evaluate multiple males, presumably to optimize mating opportunities. During this process femalesmay encounter males both familiar and novel, a distinction that might influence how mate choice pro-ceeds. Using a socially monogamous passerine, the blue-black grassquit (Volatinia jacarina), we studiedhow females respond to novel versus familiar (“paired”) males, and how encounters with novel malesinfluence subsequent interactions with their paired males. Additionally, we measured the hormonalresponse of males after visualizing their paired females interacting with novel males. We found thatfemales were attentive to novel males irrespective of these males’ phenotypic attributes, suggesting thatin these interactions novelty is highly relevant. After exposure to novel males, females tended to respondaggressively towards their paired males; by contrast, the behaviour of males towards their paired femalesdid not change. Moreover, we did not detect any hormonal responses of males to viewing their pairedfemales interacting with novel males. Together these results suggest that the distinction between famil-iarity and novelty may hold special relevance for females in mate choice, a finding that bears upon ourunderstanding of the evolution of extra-pair paternity and reproductive behaviour.
Resumo:
S’approvisionner en nourriture est essentiel à la survie et au succès reproducteur. Lorsque les animaux font face à des changements environnementaux brutaux, ils doivent s’ajuster rapidement à leur nouvel environnement et parfois même innover dans leur façon de s’approvisionner. Des processus comportementaux et cognitifs, tels que l’innovation et l’apprentissage, permettent aux animaux d'intégrer de nouveaux comportements à leur répertoire comportemental afin de s'adapter de façon optimale. Les performances cognitives varient entre les individus d’une même population et bien que des études récentes se soient intéressées aux causes de ce phénomène, de convaincantes évidences sont manquantes afin d’expliquer pourquoi ces variations sont maintenues. Au cours de ce mémoire, les questions des pressions de sélection s'exerçant sur les performances d’alimentation par une tâche motrice nouvelle sont abordées afin de mieux comprendre l'évolution des capacités cognitives au sein d'une population captive de diamants mandarins (Taeniopygia guttata). Nous avons tout d'abord testé si les femelles diamants mandarins modifient leurs préférences d'accouplement après avoir observé la performance d'alimentation par une tâche motrice nouvelle des mâles. Afin de déterminer si les femelles sont capables de discriminer entre les mâles sur la base de leur capacité cognitive, nous avons également évalué les performances d’apprentissage de chacune d’elles. En effet, des études ont suggéré qu’il peut être coûteux, spécialement en terme de temps, de discriminer entre des partenaires potentiels sur cette base. La généralisation d’une préférence pour un mâle performant à d’autres mâles possédant le même phénotype permettrait la réduction de ces coûts. Nous avons donc finalement testé si les femelles diamants mandarins peuvent généraliser leur préférence après avoir observé les performances d’alimentation pour une tâche motrice nouvelle d’un mâle. Nos résultats suggèrent que les femelles diamants mandarins ne peuvent évaluer les capacités cognitives d’un mâle par l’intermédiaire de traits indicateurs. Toutefois, nous avons démontré qu’une observation directe des performances d’alimentation d’un mâle guide le choix d’appariement des femelles. Également, nous avons montré que les femelles peuvent généraliser l’apparence du mâle le plus performant et utiliser cette information lors de l’évaluation de nouveaux mâles. La relation entre les performances cognitives et le choix de partenaire pourraient s’expliquer par exemple par une meilleure exploitation de l’habitat, mais nécessite des études plus approfondies.
Resumo:
S’approvisionner en nourriture est essentiel à la survie et au succès reproducteur. Lorsque les animaux font face à des changements environnementaux brutaux, ils doivent s’ajuster rapidement à leur nouvel environnement et parfois même innover dans leur façon de s’approvisionner. Des processus comportementaux et cognitifs, tels que l’innovation et l’apprentissage, permettent aux animaux d'intégrer de nouveaux comportements à leur répertoire comportemental afin de s'adapter de façon optimale. Les performances cognitives varient entre les individus d’une même population et bien que des études récentes se soient intéressées aux causes de ce phénomène, de convaincantes évidences sont manquantes afin d’expliquer pourquoi ces variations sont maintenues. Au cours de ce mémoire, les questions des pressions de sélection s'exerçant sur les performances d’alimentation par une tâche motrice nouvelle sont abordées afin de mieux comprendre l'évolution des capacités cognitives au sein d'une population captive de diamants mandarins (Taeniopygia guttata). Nous avons tout d'abord testé si les femelles diamants mandarins modifient leurs préférences d'accouplement après avoir observé la performance d'alimentation par une tâche motrice nouvelle des mâles. Afin de déterminer si les femelles sont capables de discriminer entre les mâles sur la base de leur capacité cognitive, nous avons également évalué les performances d’apprentissage de chacune d’elles. En effet, des études ont suggéré qu’il peut être coûteux, spécialement en terme de temps, de discriminer entre des partenaires potentiels sur cette base. La généralisation d’une préférence pour un mâle performant à d’autres mâles possédant le même phénotype permettrait la réduction de ces coûts. Nous avons donc finalement testé si les femelles diamants mandarins peuvent généraliser leur préférence après avoir observé les performances d’alimentation pour une tâche motrice nouvelle d’un mâle. Nos résultats suggèrent que les femelles diamants mandarins ne peuvent évaluer les capacités cognitives d’un mâle par l’intermédiaire de traits indicateurs. Toutefois, nous avons démontré qu’une observation directe des performances d’alimentation d’un mâle guide le choix d’appariement des femelles. Également, nous avons montré que les femelles peuvent généraliser l’apparence du mâle le plus performant et utiliser cette information lors de l’évaluation de nouveaux mâles. La relation entre les performances cognitives et le choix de partenaire pourraient s’expliquer par exemple par une meilleure exploitation de l’habitat, mais nécessite des études plus approfondies.
Resumo:
Las preferencias en elección de pareja de hombres y mujeres interesados en establecer relaciones a largo plazo con personas de su mismo sexo biológico ha sido un tema de interés para el análisis evolucionista, ya que existe debate frente a los resultados de las investigaciones y los planteamientos de las teorías de inversión parental y estrategias sexuales. Con el objetivo de identificar qué características son preferidas por hombres y mujeres interesados en establecer una relación a largo plazo con personas de su mismo sexo biológico y contribuir a esta discusión, se llevó a cabo un estudio descriptivo en el que analizamos el contenido de 732 perfiles de hombres y mujeres (H=491; M=241) que buscaban una relación estable con parejas de su mismo sexo biológico. Las categorías analizadas fueron: edad, atractivo físico (apariencia, contextura, estatura y peso), estatus socioeconómico (situación laboral, nivel educativo y zona de residencia buscada), estado civil, número de hijos y hábitos saludables (fumar y beber). Los resultados encontrados muestran que los hombres presentan rangos amplios en las características deseadas en una pareja (edad=16.87; estatura=11.37; peso=15.23) y además buscan personas menores a la edad ofrecida (M=-4.17 años). En las mujeres se encontró que los rangos son más restringidos (edad=13.85; estatura=9.83; peso=12.77) y además prefieren parejas mayores (M=2.89 años). A nivel general, se evidencia que los resultados encontrados en la mayoría de las variables podrían indicar congruencia con los planteamientos de la teoría de inversión parental y estrategias sexuales; sin embargo, en otras variables los resultados no son claros.
Resumo:
In sexually reproducing organisms, the specific combinations of parental alleles can have important consequences on offspring viability and fitness. Accordingly, genetic relationship between mates can be used as a criterion for mate choice. Here, we used microsatellite genetic markers to estimate the genetic relationship between mating pairs in the wild boar, Sus scrofa. Males, females and foetuses proceeding from Portugal, Spain and Hungary were genotyped using 14 microsatellite markers. The genetic relationship between mates was estimated using different measures of foetus heterozygosity. We found that the observed heterozygosity of foetuses was lower than that expected under random mating. This result occurred mainly when Sd2 (relatedness of parental genomes) was used as the heterozygosity measure. After simulations, we concluded that the observed low heterozygosity was possibly due to outbreeding avoidance. Outbreeding avoidance based on genetically different genomes might play an important role in species evolution and its genetic conservation.
Resumo:
It is becoming increasingly apparent that at least some aspects of the evolution of mate recognition may be amenable to manipulation in evolutionary experiments. Quantitative genetic analyses that focus on the genetic consequences of evolutionary processes that result in mate recognition evolution may eventually provide an understanding of the genetic basis of the process of speciation. We review a series of experiments that have attempted to determine the genetic basis of the response to natural and sexual selection on mate recognition in the Drosophila serrata species complex. The genetic basis of mate recognition has been investigated at three levels: (1) between the species of D. serrata and D. birchii using interspecific hybrids, (2) between populations of D. serrata that are sympatric and allopatric with respect to D. birchii, and (3) within populations of D. serrata. These experiments suggest that it may be possible to use evolutionary experiments to observe important events such as the reinforcement of mate recognition, or the generation of the genetic associations that are central to many sexual selection models.
Resumo:
We estimate and compare the performance of Portuguese-based mutual funds that invest in the domestic market and in the European market using unconditional and conditional models of performance evaluation. Besides applying both partial and full conditional models, we use European information variables, instead of the most common local ones, and consider stochastically detrended conditional variables in order to avoid spurious regressions. The results suggest that mutual fund managers are not able to outperform the market, presenting negative or neutral performance. The incorporation of conditioning information in performance evaluation models is supported by our findings, as it improves the explanatory power of the models and there is evidence of both time-varying betas and alphas related to the public information variables. It is also shown that the number of lags to be used in the stochastic detrending procedure is a critical choice, as it will impact the significance of the conditioning information. In addition, we observe a distance effect, since managers who invest locally seem to outperform those who invest in the European market. However, after controlling for public information, this effect is slightly reduced. Furthermore, the results suggest that survivorship bias has a small impact on performance estimates.
Resumo:
One debated issues in evolutionary biology is, why in many species females mate with multiple males. Several hypotheses have been put forward, yet the benefits of multiple mating (here defined as mating with several males) remain unclear in many cases. The sperm sexual selection (SSS) hypothesis has been developed to account for the widespread occurrence of multiple mating in females. It argues that multiple mating by females may rapidly spread, when initially a small fraction of the females mate multiply, and if there is a heritable difference among males in one or several of the four characteristics: (1) the quantity of sperm they produce; (2) the success of their sperm in reaching and fertilizing an egg; (3) their ability to displace the sperm that females stored during previous mating; and (4) their ability to prevent any other male from subsequently introducing sperm (e.g., differential efficiency of mating plugs).
Resumo:
How cells polarize in response to external cues is a fundamental biological problem. For mating, yeast cells orient growth toward the source of a pheromone gradient produced by cells of the opposite mating type. Polarized growth depends on the small GTPase Cdc42, a central eukaryotic polarity regulator that controls signaling, cytoskeleton polarization, and vesicle trafficking. However, the mechanisms of polarity establishment and mate selection in complex cellular environments are poorly understood. Here we show that, in fission yeast, low-level pheromone signaling promotes a novel polarization state, where active Cdc42, its GEF Scd1, and scaffold Scd2 form colocalizing dynamic zones that sample the periphery of the cell. Two direct Cdc42 effectors--actin cables marked by myosin V Myo52 and the exocyst complex labeled by Sec6 and Sec8--also dynamically colocalize with active Cdc42. However, these cells do not grow due to a block in the exocytosis of cell wall synthases Bgs1 and Bgs4. High-level pheromone stabilizes active Cdc42 zones and promotes cell wall synthase exocytosis and polarized growth. However, in the absence of prior low-level pheromone signaling, exploration fails, and cells polarize growth at cell poles by default. Consequently, these cells show altered partner choice, mating preferentially with sister rather than nonsister cells. Thus, Cdc42 exploration serves to orient growth for partner selection. This process may also promote genetic diversification.
Resumo:
We examine the effect of unilateral and mutual partner selection in the context of prisoner's dilemmas experimentally. Subjects play simultaneously several finitely repeated two-person prisoner's dilemma games. We find that unilateral choice is the best system. It leads to low defection and fewer singles than with mutual choice. Furthermore, with the unilateral choice setup we are able to show that intendingdefectors are more likely to try to avoid a match than intending cooperators. We compare our results of multiple games with single game PD-experiments and find no difference in aggregate behavior. Hence the multiple game technique is robust and might therefore be an important tool in the future for testing the use of mixed strategies.
Resumo:
The present research was conducted in two studies. The first study examined how mating intelligence, self-esteem, and self-perceived attractiveness are related to each other. The second study examined how these three constructs relate to partner choice. It was hypothesized that participants who score high on mating intelligence will also score high on self-esteem and self-perceived attractiveness. Furthermore, those that score high on self-esteem will also score high on self-perceived attractiveness. It was expected that the results would be more significant for women than for men. For the second study, it was hypothesized that participants who score high on all three constructs will be more likely to select the attractive partner. The results did not show a significant interaction between mating intelligence, self-esteem, and self-perceived attractiveness. They also did not indicate higher significance levels for women. However, there were significant effects between the constructs. Additionally, participants with an average or a high score on mating intelligence were more likely to select the attractive partner.
Resumo:
Background: A small pond, c. 90 years old, near Bern, Switzerland contains a population of threespine stickleback (Gasterosteus aculeatus) with two distinct male phenotypes. Males of one type are large, and red, and nest in the shallow littoral zone. The males of the other are small and orange, and nest offshore at slightly greater depth. The females in this population are phenotypically highly variable but cannot easily be assigned to either male type. Question: Is the existence of two sympatric male morphs maintained by substrate-associated male nest site choice and facilitated by female mate preferences? Organisms: Male stickleback caught individually at their breeding sites. Females caught with minnow traps. Methods: In experimental tanks, we simulated the slope and substrate of the two nesting habitats. We then placed individual males in a tank and observed in which habitat the male would build his nest. In a simultaneous two-stimulus choice design, we gave females the choice between a large, red male and a small, orange one. We measured female morphology and used linear mixed effect models to determine whether female preference correlated with female morphology. Results: Both red and orange males preferred nesting in the habitat that simulated the slightly deeper offshore condition. This is the habitat occupied by the small, orange males in the pond itself. The proportion of females that chose a small orange male was similar to that which chose a large red male. Several aspects of female phenotype correlated with the male type that a female preferred.
Resumo:
Avian plumage has long been used to test theories of sexual selection, with humans assessing the colors. However, many birds see in the ultraviolet (<400 nm), to which humans are blind. Consequently, it is important to know whether natural variation in UV reflectance from plumage functions in sexual signaling. We show that female starlings rank males differently when UV wavelengths are present or absent. Principal component analysis of ≈1300 reflectance spectra (300–700 nm) taken from sexually dimorphic plumage regions of males predicted preference under the UV+ treatment. Under UV− conditions, females ranked males in a different and nonrandom order, but plumage reflectance in the human visible spectrum did not predict choice. Natural variation in UV reflectance is thus important in avian mate assessment, and the prevailing light environment can have profound effects on observed mating preferences.
Resumo:
Ukraine and Russia: Among all of the countries that border Ukraine, the Russian Federation is its most important partner. Ukraine's relations with Moscow are the key issue of its foreign policy to such an extent that each option of the Ukrainian foreign policy is first and foremost a choice as to the shape of its relations with Russia. This is mainly a consequence of Ukraine's geographic and geopolitical situation, the legacy of many centuries of political, economic and cultural bonds between these two countries, as well as Russia's inevitably dominant position in their mutual relations. Belarus: Belarus has not broken off its bonds with Moscow after the break-up of the Soviet Union. Throughout the whole period of the Belarussian independence we can observe the country's strong political, economic and military dependence on Russia. This dependence allows Russia to control, and even shape, the processes that take place in Belarus in all the areas mentioned.