479 research outputs found
Arbitrariness, iconicity, and systematicity in language
The notion that the form of a word bears an arbitrary relation to its meaning accounts only partly for the attested relations between form and meaning in the languages of the world. Recent research suggests a more textured view of vocabulary structure, in which arbitrariness is complemented by iconicity (aspects of form resemble aspects of meaning) and systematicity (statistical regularities in forms predict function). Experimental evidence suggests these form-to-meaning correspondences serve different functions in language processing, development, and communication: systematicity facilitates category learning by means of phonological cues, iconicity facilitates word learning and communication by means of perceptuomotor analogies, and arbitrariness facilitates meaning individuation through distinctive forms. Processes of cultural evolution help to explain how these competing motivations shape vocabulary structure
A statistical methodology for estimating assortative mating for phenotypic traits that are labile or measured with error
Assortative
mating in wild populations is commonly reported as the correlation
between malesâ and femalesâ phenotypes across mated pairs. Theories of
partner selection and quantitative genetics assume that phenotypic
resemblance of partners captures associations in âintrinsically
determinedâ trait values. However, when considering traits with a
repeatability below one (labile traits or traits measured with error),
the correlation between phenotypes of paired individuals can arise from
shared environmental effects on the phenotypes of paired individuals or
correlated measurement error.We introduce statistical
approaches to estimate assortative mating in labile traits or traits
measured with error in the presence of shared environmental effects.
These approaches include (1) the correlation between the mean phenotypes
of males and females, (2) the correlation between randomized values of
individuals and (3) the between-pair correlation derived from a
bivariate mixed model.We use simulations to show that the
performance of these different approaches depends on the number of
repeated measures within individuals or pairs, which is determined by
study design, and rates of survival and divorce.We conclude
that short-term environmental effects on phenotypes of paired
individuals likely inflate estimates of assortative mating when not
statistically accounted for. Our approach allows investigation of this
important issue in assortative mating studies for labile traits (e.g.
behaviour, physiology, or metabolism) in both socially monogamous and
other mating systems, and groupings of individuals outside a mating
context.</ol
Male song stability shows crossâyear repeatability but does not affect reproductive success in a wild passerine bird
Abstract
Predictable behaviour (or âbehavioural stabilityâ) might be favoured in certain ecological contexts, for example when representing a quality signal. Costs associated with producing stable phenotypes imply selection should favour plasticity in stability when beneficial. Repeatable amongâindividual differences in degree of stability are simultaneously expected if individuals differ in ability to pay these costs, or in how they resolve costâbenefit tradeâoffs.
Bird song represents a prime example, where stability may be costly yet beneficial when stable singing is a quality signal favoured by sexual selection. Assuming energetic costs, ecological variation (e.g. in food availability) should result in both withinâ and amongâindividual variation in stability. If song stability represents a quality signal, we expect directional selection favouring stable singers.
For a 3âyear period, we monitored 12 nest box plots of great tits Parus major during breeding. We recorded male songs during simulated territory intrusions, twice during their mate's laying stage and twice during incubation. Each preceding winter, we manipulated food availability. Assuming that stability is costly, we expected foodâsupplemented males to sing more stable songs. We also expected males to sing more stable songs early in the breeding season (when paternity is not decided) and stable singers to have increased reproductive success.
We found strong support for plasticity in stability for two key song characteristics: minimum frequency and phrase length. Males were plastic because they became more stable over the season, contrary to expectations. Food supplementation did not affect body condition but increased stability in minimum frequency. This treatment effect occurred only in 1âyear, implying that food supplementation affected stability only in interaction with (unknown) yearâspecific ecological factors.
We found no support for directional, correlational or fluctuating selection on the stability in minimum frequency (i.e. the song trait whose stability exhibited crossâyear repeatability): stable singers did not have higher reproductive success. Our findings imply that stability in minimum frequency is not a fitness quality indicator unless males enjoy fitness benefits via pathways not studied here. Future studies should thus address the mechanisms shaping and maintaining individual repeatability of song stability in the wild.
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Repeated genomic signatures of adaptation to urbanisation in a songbird across Europe
Urbanisation is currently increasing worldwide, and there is now ample evidence of phenotypic changes in wild organisms in response to this novel environment, but the extent to which this adaptation is due to genetic changes is poorly understood. Current evidence for evolution is based on localised studies, and thus lacking replicability. Here, we genotyped great tits (Parus major) from nine cities across Europe, each paired with a rural site, and provide evidence of repeated polygenic responses to urban habitats. In addition, we show that selective sweeps occurred in response to urbanisation within the same genes across multiple cities. These genetic responses were mostly associated with genes related to neural function and development, demonstrating that genetic adaptation to urbanisation occurred around the same pathways in wildlife populations across a large geographical scale.Competing Interest StatementThe authors have declared no competing interest
Consistency in context-specific measures of shyness and boldness in rainbow trout, Oncorhynchus mykiss
Shyness and boldness has been considered a fundamental axis of human behavioural variation. At the extreme ends of this behavioural continuum subjects vary from being bold and assertive to shy and timid. Analogous patterns of individual variation have been noted in a number of species including fish. There has been debate on the nature of this continuum as to whether it depends on context. That is, whether it is domain-general (as in humans), or context-specific. The purpose of our study was to test if shyness and boldness depends on context in rainbow trout, Oncorhynchus mykiss and to this end we estimated boldness in five different situations. Our data provide evidence of a shy-bold behavioural syndrome in rainbow trout. Bold trout tended to be bold in four situations when the context was similar (when the context concerned foraging). However, in a different context, exploring a swim flume, the ranking was entirely different. We suggest that shyness and boldness depends on context in rainbow trout. © 2005 Blackwell Verlag
Does song overlap signal aggressiveness?: An experimental study with repeated measures in free-ranging great tits
Vocal communication is often used to signal willingness to escalate into a physical fight during territorial conflicts. In songbirds, starting to sing when an opponent already sings (song overlapping) has been suggested to signal aggressive intent (willingness to escalate). We used a multiyear data set to test whether song overlapping predicts aggressiveness in great tits, Parus major. Territorial males were subjected twice to a simulated territorial intrusion when their mate was in the egg-laying phase, and twice when she was incubating. Males were presented with a taxidermic mount and a noninteractive playback of a conspecific song near their nestbox. The experiment was conducted over 3 consecutive years, resulting in repeated measures for males that bred across multiple years. The estimated minimum approach distance to the intruder, a repeatable and heritable trait that predicts the likelihood of physical attack, was used as a measure of aggression. We determined the duration of song overlapping by the focal male relative to values expected by chance. Against expectations, we found that birds that over -lapped were less (rather than more) aggressive. In addition, variance partitioning demonstrated that this link resulted from a within-individual effect: when birds became less aggressive from one observation to the next, they also overlapped more. There was no among-individual effect: individuals that were on average more aggressive did not, on average, overlap either more or less than others. Our results thus imply that song overlapping is linked to aggression but opposite to expectations, and not among in-dividuals. Furthermore, the majority of birds overlapped at or below chance levels. Overall, song over-lapping may not signal aggressive intent but rather 'nonengagement', or result from interference avoidance, allowing aggressive residents to better hear an intruder's acoustic output during territorial intrusions. (c) 2021 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.Animal science
Dependencies in language: On the causal ontology of linguistic systems
Dependency is a fundamental concept in the analysis of linguistic systems. The many if-then statements offered in typology and grammar-writing imply a causally real notion of dependency that is central to the claim being madeâusually with reference to widely varying timescales and types of processes. But despite the importance of the concept of dependency in our work, its nature is seldom defined or made explicit. This book brings together experts on language, representing descriptive linguistics, language typology, functional/cognitive linguistics, cognitive science, research on gesture and other semiotic systems, developmental psychology, psycholinguistics, and linguistic anthropology to address the following question: What kinds of dependencies exist among language-related systems, and how do we define and explain them in natural, causal terms
Dependencies in language: On the causal ontology of linguistic systems
Dependency is a fundamental concept in the analysis of linguistic systems. The many if-then statements offered in typology and grammar-writing imply a causally real notion of dependency that is central to the claim being madeâusually with reference to widely varying timescales and types of processes. But despite the importance of the concept of dependency in our work, its nature is seldom defined or made explicit. This book brings together experts on language, representing descriptive linguistics, language typology, functional/cognitive linguistics, cognitive science, research on gesture and other semiotic systems, developmental psychology, psycholinguistics, and linguistic anthropology to address the following question: What kinds of dependencies exist among language-related systems, and how do we define and explain them in natural, causal terms
Dependencies in language: On the causal ontology of linguistic systems
Dependency is a fundamental concept in the analysis of linguistic systems. The many if-then statements offered in typology and grammar-writing imply a causally real notion of dependency that is central to the claim being madeâusually with reference to widely varying timescales and types of processes. But despite the importance of the concept of dependency in our work, its nature is seldom defined or made explicit. This book brings together experts on language, representing descriptive linguistics, language typology, functional/cognitive linguistics, cognitive science, research on gesture and other semiotic systems, developmental psychology, psycholinguistics, and linguistic anthropology to address the following question: What kinds of dependencies exist among language-related systems, and how do we define and explain them in natural, causal terms
Dependencies in language: On the causal ontology of linguistic systems
Dependency is a fundamental concept in the analysis of linguistic systems. The many if-then statements offered in typology and grammar-writing imply a causally real notion of dependency that is central to the claim being madeâusually with reference to widely varying timescales and types of processes. But despite the importance of the concept of dependency in our work, its nature is seldom defined or made explicit. This book brings together experts on language, representing descriptive linguistics, language typology, functional/cognitive linguistics, cognitive science, research on gesture and other semiotic systems, developmental psychology, psycholinguistics, and linguistic anthropology to address the following question: What kinds of dependencies exist among language-related systems, and how do we define and explain them in natural, causal terms
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