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Weissing, F. J.

Publications and source records attributed to Weissing, F. J..

4 recordsLinked to original sources

How do ecological and social environments reflect parental roles in birds? A comparative analysis

Parental roles are highly diverse in animal taxa. Since caring is an important determinant of fitness, understanding the origin and maintenance of various parental care strategies is a key question in evolutionary biology. Here we investigate parental care patterns in birds, which exhibit a remarkable diversity of parental sex roles. By means of phylogenetically informed comparative analyses we investigate whether and how care provisioning is predicted by ecology and social environment. Making use of the most comprehensive dataset including 1101 species that represent 126 avian families, we show that sex differences in parental care are neither related to food type nor to nest type, two key ecological factors. However, we found an effect of the social environment, as males tend to care relatively more in in colonial species than in non-colonial species. Taken together, these results highlight the importance of social effects for evolution of diverse parental sex roles.

evolutionary biology

Complex eco-evolutionary dynamics induced by the coevolution of predator-prey movement strategies

The coevolution of predators and prey has been the subject of much empirical and theoretical research, which has produced intriguing insights into the intricacies of eco-evolutionary dynamics. Mechanistically detailed models are rare, however, because the simultaneous consideration of individual-level behaviour (on which natural selection is acting) and the resulting ecological patterns is challenging and typically prevents mathematical analysis. Here we present an individual-based simulation model for the coevolution of predators and prey on a fine-grained resource landscape. Throughout their lifetime, predators and prey make repeated movement decisions on the basis of heritable and evolvable movement strategies. We show that these strategies evolve rapidly, inducing diverse ecological patterns like spiral waves and static spots. Transitions between these patterns occur frequently, induced by coevolution rather than by external events. Regularly, evolution leads to the emergence and stable coexistence of qualitatively different movement strategies. Although the strategy space considered is continuous, we often observe discrete variation. Accordingly, our model includes features of both population genetic and quantitative genetic approaches to coevolution. The model demonstrates that the inclusion of a richer ecological structure and higher number of evolutionary degrees of freedom results in even richer eco-evolutionary dynamics than anticipated previously.

evolutionary biology

Individual variation in parental care drives divergence of sex roles

In many animal species, parents provide care for their offspring, but the parental roles of the two sexes differ considerably between and within species. Here, we use an individual-based simulation approach to investigate the evolutionary emergence and stability of parental roles. Our conclusions are in striking contrast to the results of analytical models. In the absence of initial differences between the sexes, our simulations do not predict the evolution of egalitarian care, but either female-biased or male-biased care. When the sexes differ in their pre-mating investment, the sex with the highest investment tends to evolve a higher level of parental care; this outcome does not depend on non-random mating or uncertainty of paternity. If parental investment evolves jointly with sexual selection strategies, evolution results in either the combination of female-biased care and female choosiness or in male-biased care and the absence of female preferences. The simulations suggest that the parental care pattern drives sexual selection, and not vice versa. Finally, our model reveals that a population can rapidly switch from one type of equilibrium to another one, suggesting that parental sex roles are evolutionarily labile. By combining simulation results with fitness calculations, we argue that all these results are caused by the emergence of individual variation in parental care strategies, a factor that was hitherto largely neglected in sex-role evolution theory.

evolutionary biology

Phenotypic plasticity explains violation of Dollo's law

Over the last few decades, numerous examples have been described where a trait that was once lost during the course of evolution had been regained. Here, we argue that such reverse evolution can also become apparent when trait expression is plastic in response to the environment. We tested this hypothesis for the loss and regain of fat synthesis in parasitic wasps. Wasps from lineages that supposedly regained lipogenic ability ~80 million years ago were grown under a fat-poor or fat-rich environment. In line with our hypothesis, it turned out that fat synthesis had not been lost and regained, but was only switched on in low-fat environments. Functional protein domains of key lipogenesis genes were also found in other parasitoid species, suggesting that plasticity of fat synthesis may be more widespread in parasitoids. Individual-based simulations then revealed that a switch for plastic expression can remain functional in the genome for thousands of generations, even if it is only used sporadically. The evolution of plasticity may thus also explain other examples of apparent reverse evolution.

evolutionary biology