Search results for "SEL"
showing 10 items of 14031 documents
Can we rely on selected genetic markers for population identification? Evidence from coastal Atlantic cod
2018
Abstract The use of genetic markers under putative selection in population studies carries the potential for erroneous identification of populations and misassignment of individuals to population of origin. Selected markers are nevertheless attractive, especially in marine organisms that are characterized by weak population structure at neutral loci. Highly fecund species may tolerate the cost of strong selective mortality during early life stages, potentially leading to a shift in offspring genotypes away from the parental proportions. In Atlantic cod, recent genetic studies have uncovered different genotype clusters apparently representing phenotypically cryptic populations that coexist i…
A Migratory Divide Among Red-Necked Phalaropes in the Western Palearctic Reveals Contrasting Migration and Wintering Movement Strategies
2019
Publisher's version (útgefin grein)
The enigma of frequency-dependent selection
1997
Frequency-dependent selection is so fundamental to modern evolutionary thinking that everyone interested in evolutionary biology 'knows' the concept. It is even so fundamental that many authors of textbooks do not bother to define it. Yet it turns out that different authors (and sometimes even one and the same author) use the term to refer to different types of selection. In this paper we try to uncover the sources of this confusion. The concept is fairly well defined in the original concept of population genetical theory, which focuses on short-term evolutionary change, and basically ignores density-dependence. The problems start when the original concept is used in the context of long-ter…
Embryonic survival and larval predator-avoidance ability in mutually ornamented whitefish
2011
Mutual ornamentation (i.e. the expression of secondary sexual characters) in both sexes is a relatively common but rarely studied phenomenon in the animal kingdom. In the present study, we investigated whether mutual ornamentation is indicative of offspring embryonic survival and predator-avoidance ability in whitefish. We crossed ten randomly selected females and ten randomly selected males in all possible combinations resulting in 100 sib groups, and hypothesized that fitness (measured as offspring survival) of elaborately ornamented parents would be higher in both sexes of whitefish. Parental effects were found in both studied traits: effects of female and female–male interaction were si…
Debating Sexual Selection and Mating Strategies
2006
Published at full length with the title 'Reproductive behaviour: sexual selection remains the best explanation' in Science E-letters, 6 April 2006
Do allopatric maleCalopteryx virgodamselflies learn species recognition?
2012
There is a growing amount of empirical evidence that premating reproductive isolation of two closely related species can be reinforced by natural selection arising from avoidance of maladaptive hybridization. However, as an alternative for this popular reinforcement theory, it has been suggested that learning to prefer conspecifics or to discriminate heterospecifics could cause a similar pattern of reinforced premating isolation, but this possibility is much less studied. Here, we report results of a field experiment in which we examined (i) whether allopatric Calopteryx virgo damselfly males that have not encountered heterospecific females of the congener C. splendens initially show discri…
Parental care shapes evolution of aposematism and provides lifelong protection against predators
2019
ABSTRACTSocial interactions within species can modulate the response to selection and determine the extent of evolutionary change. Yet relatively little work has determined whether the social environment can influence the evolution of traits that are selected by interactions with other species - a major source of natural selection. Here we show that the amount of parental care received as an offspring can influence the expression, and potential evolution, of warning displays deployed against predators in adulthood. In theory, warning displays by prey are selected by predators for uniformity and to reliably advertise the extent to which individuals are chemically defended. However, the corre…
Patterns of morphological variation in two sexually dimorphic bird species with different tail shapes
2007
Many studies have focused on tail ornamentation in birds, but not all tail shapes have been studied in depth. Graduated and pin tails have received less attention than forked tails, despite being more likely, in terms of aerodynamic theory, to be honest signals. We report morphological variation in live specimens of two sexually dimorphic passerines from the same site with different tail shapes: graduated (Cape sugarbird Promerops cafer ) and pin (orangebreasted sunbird Antobaphes violacea ). Coefficients of variation (CVs) were calculated for all morphological traits, both non-ornamental (range 1.91–5.72) and ornamental (range 5.83–21.71). Males and females did not differ in CV for any non…
Acidic shell proteins of the Mediterranean fan mussel Pinna nobilis.
2011
43 pages; In molluscs, the shell secretion process is controlled by a set of extracellular macromolecules collectively called the shell matrix. The shell matrix, which is produced by the mantle epithelial cells during mineralization, is predominantly composed of proteins, glycoproteins, acidic polysaccharides, and chitin that precisely regulate the deposition of calcium carbonate outside the mantle cells. In the present paper, we focus on the shell of Pinna nobilis, the giant Mediterranean fan mussel, usually considered as a model for studying molluscan biomineralization processes. P. nobilis exhibits indeed a nacro-prismatic shell, the outer layer of which is constituted of the so-called "…
Rapid Diversification of Sperm Precedence Traits and Processes Among Three Siblingdrosophilaspecies: Divergent Sperm Precedence Mechanisms
2013
Postcopulatory sexual selection is credited with driving rapid evolutionary diversification of reproductive traits and the formation of reproductive isolating barriers between species. This judgment, however, has largely been inferred rather than demonstrated due to general lack of knowledge about processes and traits underlying variation in competitive fertilization success. Here, we resolved processes determining sperm fate in twice-mated females, using transgenic Drosophila simulans and Drosophila mauritiana populations with fluorescently labeled sperm heads. Comparisons among these two species and Drosophila melanogaster revealed a shared motif in the mechanisms of sperm precedence, wit…