Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS Biol ; 14(12): e1002589, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28033324

RESUMO

[This corrects the article DOI: 10.1371/journal.pbio.1002564.].

2.
PLoS Biol ; 14(10): e1002564, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27701411

RESUMO

Social insects make elaborate use of simple mechanisms to achieve seemingly complex behavior and may thus provide a unique resource to discover the basic cognitive elements required for culture, i.e., group-specific behaviors that spread from "innovators" to others in the group via social learning. We first explored whether bumblebees can learn a nonnatural object manipulation task by using string pulling to access a reward that was presented out of reach. Only a small minority "innovated" and solved the task spontaneously, but most bees were able to learn to pull a string when trained in a stepwise manner. In addition, naïve bees learnt the task by observing a trained demonstrator from a distance. Learning the behavior relied on a combination of simple associative mechanisms and trial-and-error learning and did not require "insight": naïve bees failed a "coiled-string experiment," in which they did not receive instant visual feedback of the target moving closer when tugging on the string. In cultural diffusion experiments, the skill spread rapidly from a single knowledgeable individual to the majority of a colony's foragers. We observed that there were several sequential sets ("generations") of learners, so that previously naïve observers could first acquire the technique by interacting with skilled individuals and, subsequently, themselves become demonstrators for the next "generation" of learners, so that the longevity of the skill in the population could outlast the lives of informed foragers. This suggests that, so long as animals have a basic toolkit of associative and motor learning processes, the key ingredients for the cultural spread of unusual skills are already in place and do not require sophisticated cognition.


Assuntos
Abelhas/fisiologia , Comportamento Animal , Aprendizagem , Comportamento Social , Animais , Análise e Desempenho de Tarefas
3.
Biol Lett ; 12(6)2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27303053

RESUMO

To understand the relative benefits of social and personal information use in foraging decisions, we developed an agent-based model of social learning that predicts social information should be more adaptive where resources are highly variable and personal information where resources vary little. We tested our predictions with bumblebees and found that foragers relied more on social information when resources were variable than when they were not. We then investigated whether socially salient cues are used preferentially over non-social ones in variable environments. Although bees clearly used social cues in highly variable environments, under the same conditions they did not use non-social cues. These results suggest that bumblebees use a 'copy-when-uncertain' strategy.


Assuntos
Abelhas/fisiologia , Animais , Comportamento Apetitivo , Aprendizagem por Associação , Sinais (Psicologia) , Flores , Comportamento Social , Incerteza
4.
Evolution ; 68(12): 3524-36, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25308282

RESUMO

Fisher's mechanism of sexual selection is a fundamental element of evolutionary theory. In it nonrandom mate choice causes a genetic covariance between a male trait and female preference for that trait and thereby generates a positive feedback process sustaining accelerated coevolution of the trait and preference. Numerous theoretical models of Fisher's mechanism have confirmed its mathematical underpinnings, yet biologists have often failed to find evidence for trait-preference genetic correlation in populations in which the mechanism was expected to function. We undertook a survey of the literature to conduct a formal meta-analysis probing the incidence and strength of trait-preference correlation among animal species. Our meta-analysis found significant positive genetic correlations in fewer than 20% of the species studied and an overall weighted correlation that is slightly positive. Importantly, a significant positive correlation was not found in any thorough study that included multiple subgroups. We discuss several ways in which the dynamic, multivariate nature of mate choice may reduce the trait-preference genetic correlation predicted by Fisher's mechanism. We then entertain the possibilities that Fisherian-like processes sometimes function without genetic correlation, and that mate choice may persist in a population as long as genetic correlation, and therefore Fisher's mechanism, occurs intermittently.


Assuntos
Evolução Molecular , Preferência de Acasalamento Animal , Seleção Genética , Animais , Feminino , Masculino , Característica Quantitativa Herdável
5.
PLoS One ; 7(9): e44554, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22957082

RESUMO

Models of indirect (genetic) benefits sexual selection predict linkage disequilibria between genes that influence male traits and female preferences, owing to non-random mate choice or physical linkage. Such linkage disequilibria can accelerate the evolution of traits and preferences to exaggerated levels. Both theory and recent empirical findings on species recognition suggest that such linkage disequilibria may result from physical linkage or pleiotropy, but very little work has addressed this possibility within the context of sexual selection. We studied the genetic architecture of sexually selected traits by analyzing signals and preferences in an acoustic moth, Achroia grisella, in which males attract females with a train of ultrasound pulses and females prefer loud songs and a fast pulse rhythm. Both male signal characters and female preferences are repeatable and heritable traits. Moreover, female choice is based largely on male song, while males do not appear to provide direct benefits at mating. Thus, some genetic correlation between song and preference traits is expected. We employed a standard crossing design between inbred lines and used AFLP markers to build a linkage map for this species and locate quantitative trait loci (QTL) that influence male song and female preference. Our analyses mostly revealed QTLs of moderate strength that influence various male signal and female receiver traits, but one QTL was found that exerts a major influence on the pulse-pair rate of male song, a critical trait in female attraction. However, we found no evidence of specific co-localization of QTLs influencing male signal and female receiver traits on the same linkage groups. This finding suggests that the sexual selection process would proceed at a modest rate in A. grisella and that evolution toward exaggerated character states may be tempered. We suggest that this equilibrium state may be more the norm than the exception among animal species.


Assuntos
Mariposas/genética , Mariposas/fisiologia , Locos de Características Quantitativas , Acústica , Comunicação Animal , Animais , Cruzamentos Genéticos , Primers do DNA/genética , Ecologia , Feminino , Genótipo , Cariotipagem , Desequilíbrio de Ligação , Masculino , Modelos Genéticos , Fenótipo , Fatores Sexuais , Pré-Seleção do Sexo , Comportamento Sexual Animal , Canto , Vocalização Animal
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...