Rebecca Kilner How behavior changes evolution: experiments with burying beetles Summary:Behavioural ecologists analyse animal behaviour to understand how it is adaptive, and therefore why it persists. In our lab, the focus is slightly different. We want to know how adaptive traits, like animal behaviour, influence the subsequent course of evolution. We address this question by using experimental evolution and we focus in particular on a social trait, namely parental care. Our model species is the burying beetle, a remarkable insect that breeds upon the body of a small dead vertebrate. It shows elaborate parental care, which involves preparing the carcass to make an edible nest for its offspring and provisioning larvae after hatching. I will describe experiments that manipulate the provision of parental care and measure the way in which traits then evolve and adapt, in both parents and offspring. The general conclusion is that there are diverse ways in which behaviour can change evolution. |
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Elizabeth Tibbetts Animal signals influence social behavior, physiology, and cognition: Lessons from wasp faces Summary: The effects of animal signals extend beyond social interactions to shape the way animals look, think, act, and evolve. In the first section of the talk, I will draw examples from multiple taxa to illustrate that communication is a key factor shaping phenotypic and genetic diversity in social animals. The goal is to develop a useful framework for future behavioral and evolutionary research on animal signals. I will show how signals that convey different kinds of information differ in terms of the type of selection acting on signalers, patterns of phenotypic variation, developmental mechanisms, and evolutionary consequences. In the second section of the talk, I will experimentally examine the factors that prevent low-quality individuals from cheating by signaling that they are strong. Experiments in paper wasps show that dishonest individuals are aggressively punished, and this punishment has lasting effects on the physiology of the dishonest signaler and those they interact with. Therefore, interactions between behavioral and physiological costs of dishonesty could play an important role in maintaining honest communication over evolutionary time. |
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Anita Aisenberg Journey to an upside-down world: a transgressive South American spider as a model for sexual selection studies Summary: This talk will be focused on the outstanding Allocosa brasiliensis, a sand-burrowing spider that inhabits the coasts of South America. Conversely to what is expected in spiders, males are larger than females, while females are wanderers that look for mating partners and initiate courtship. Both sexes are choosy when it is time for mating: females prefer males with long burrows and males prefer virgin females with good body condition. Furthermore, males can attack and cannibalize rejected females. This Neotropical species gives us the opportunity to study the factors governing their atypical behaviors, while discussing the causes shaping sex roles in spiders. In this talk we will get to know this spider-exception through a journey to experimental and field-work performed on this species, ending with perspectives for future studies. |
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William Searcy Bird song and the problem of signal reliability Summary: Signaling systems are expected to be stable only if signals are to some extent reliable, but the maintenance of reliability is a problem in all systems in which the interests of signalers and receivers are not identical. Among the mechanisms proposed to maintain reliability, three seem particularly important: the handicap mechanism, in which reliability is maintained by intrinsic signal costs; conventional signaling, in which reliability is maintained by receiver-dependent costs; and index signaling, in which physical or informational constraints impose honesty. All three of these mechanisms can be found acting on bird song. Intrinsic costs imposed during development reliably tie developmental history to learned aspect of song, explaining female preferences for better-learned songs. Receiver dependent costs act on aggressive signals, explaining the otherwise puzzling reliability of specific song signals as predictors of aggression. Recent findings have shown that informational constraints make duet codes and duet coordination reliable signals of pair stability. |
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Molly Morris The evolution of alternative reproductive tactics Summary: Variation within a species has long been appreciated by evolutionary biologists, given that genetically influenced variation is necessary for evolution. However, the presence of discrete differences in morphology, behavior and physiology suggests multiple optima, or adaptive variation. Alternative reproductive tactics (ARTs) are prime examples of adaptive variation in suites of life history traits that can provide valuable insights into several areas of active research. I first highlight how work on the evolution of ARTs in swordtail fishes could lead to a better understanding of the evolution of behavioral plasticity, genetic assimilation and constraints on the evolution of tactical dimorphisms. Second, I consider the role that variation in female mate preference and sexual conflict has played in increasing our understanding of the evolution of ARTs within ARTs within ARTs. And finally, I suggest how the conceptual underpinnings of the evolution of ARTs could potentially be applied to research on diabetes in humans. |
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James Dale Plumage colour in males and females Summary: Research on animal coloration has led to amazing insights into the nature of natural selection, sexual selection, sensory ecology and the evolutionary maintenance of biological diversity. However quantifying coloration can be challenging because it is a complex, multi-dimensional trait that is often perceived differently by the animals under investigation and the investigators themselves. In this talk I will first review methods to quantify “colour elaboration”. Using birds as a model system, I will then argue that quantifying how “male-like” or “female-like” a colour is provides an intuitive and effective means for interspecific comparison of colour diversity. Finally, I will apply this method to the ~6000 species of perching birds (Order: Passeriformes) to help resolve some of the key evolutionary predictors of colour elaboration in both sexes. |