AbstractsBiology & Animal Science

Can social learning promote hybridisation? : mate-choice cpying in Drosophila subobscura populations

by Gonçalo Faria Silva




Institution: Universidade de Lisboa
Department:
Year: 2014
Keywords: Hibridização; Drosophila subobscura; Comportamento animal; Acasalamento; Teses de mestrado - 2014
Record ID: 1318315
Full text PDF: http://www.rcaap.pt/detail.jsp?id=oai:repositorio.ul.pt:10451/15315


Abstract

Tese de mestrado. Biologia (Biologia Evolutiva e do Desenvolvimento). Universidade de Lisboa, Faculdade de Ciências, 2014 Mate-choice copying (MCC) by females (although the same behaviour can be found on males) occurs when they obtain information about the mating performance of a male with other females, increasing or decreasing their preference for that male, accordingly. MCC generalization occurs when males with similar phenotypes to the first one are also preferred. This behavioural pattern has been found in several species, including one species of invertebrate, Drosophila melanogaster. MCC may lead to reproductive isolation between populations from the same species, since it can be responsible for a cultural divergence of mating preferences. However, if immigrant individuals copy the choices of natives, this can also lead to hybridisation events. Moreover, since MCC changes female preferences based on male attractiveness, they might wish to invest more in the offspring of those attractive males (differential reproductive allocation). Taking all these into account, we were able to see that MCC is present in another invertebrate species, Drosophila subobscura. We simulated a scenario where populations from the two extremes of this species latitudinal cline (NL from the Netherlands and PT from Portugal) immigrated to a new (lab) environment with a resident TA population (adapted to the lab for several generations). Our aim was to test the hybridisation and differential allocation hypotheses of NL and PT with TA. We found that MCC is population dependent, occurring in PT but not in NL. PT females copied TA females when they chose PT males. However, copying seems to have little or no contribution to the process of hybridisation, because PT females’ innate preference for TA males was already at 80% and copying TA females when they chose TA males did not increase this preference. MCC also seems to have no effect on female reproductive investment, although we found that female choice (compared to no-choice controls) can increase offspring’s juvenile viability. Tendo como resultado o aumento do “fitness”, conceito central em biologia evolutiva, as pressões selectivas podem ter levado os indivíduos a adoptar comportamentos no sentido de reduzirem o erro associado à escolha de um parceiro sexual. “Mate-choice copying” (MCC) é a designação para a alteração da preferência sexual de uma fêmea (embora também possa estar presente em machos) mediante a informação social que recebe para um determinado macho, quando este acasala com sucesso com outra(s) fêmea(s). Pensa-se que o MCC permitem às fêmeas fazerem melhores escolhas, tendo assim um impacto positivo no seu fitness. O MCC pode ser generalizado a outros indivíduos com fenótipo semelhante, sendo este um componente essencial para a evolução de preferências culturais sexuais. Este padrão comportamental tem vindo a ser descrito num número crescente de espécies. Contudo, em invertebrados, apenas se sabe estar presente em Drosophila melanogaster. Tem também vindo a ser…