The evolution of trade‐offs: where are we?
... two uncorrelated traits made up from a linear combination of the original two correlated traits, with the eigenvalues being the genetic variances of these two synthesized traits (Kirkpatrick & Lofsvold, 1992). When r ¼ )1 there is no variation in the direction of the minor axis (the second eigenvalu ...
... two uncorrelated traits made up from a linear combination of the original two correlated traits, with the eigenvalues being the genetic variances of these two synthesized traits (Kirkpatrick & Lofsvold, 1992). When r ¼ )1 there is no variation in the direction of the minor axis (the second eigenvalu ...
NATURAL SELECTION
... of trait C is in part explained by the prior selection event. Matthen argues that in order to defend his view, sober would have to rely on a contentio¡s ontological assumption about origin essentialism - in particular, he must assume that a particular sheep such as Dolly must come from the parents i ...
... of trait C is in part explained by the prior selection event. Matthen argues that in order to defend his view, sober would have to rely on a contentio¡s ontological assumption about origin essentialism - in particular, he must assume that a particular sheep such as Dolly must come from the parents i ...
Sex and sensibility: The role of social selection
... At the heart of Roughgarden’s book is a two-prong strategy: first, she claims that modern sexual selection theory must be rejected; second, she proposes an alternative framework, social selection, to explain the evolution of sexual diversity in the animal kingdom. In many ways, her dismissal of sexu ...
... At the heart of Roughgarden’s book is a two-prong strategy: first, she claims that modern sexual selection theory must be rejected; second, she proposes an alternative framework, social selection, to explain the evolution of sexual diversity in the animal kingdom. In many ways, her dismissal of sexu ...
DETECTING CRYPTIC INDIRECT GENETIC EFFECTS
... partners are allowed to vary, focal phenotypes can be regressed on interacting partner phenotypes. The resulting partial regression coefficient associated with the phenotypes, ψ, provides an estimate of the magnitude and direction of any IGEs (Moore et al. 1997; Bleakley et al. 2010). The interactio ...
... partners are allowed to vary, focal phenotypes can be regressed on interacting partner phenotypes. The resulting partial regression coefficient associated with the phenotypes, ψ, provides an estimate of the magnitude and direction of any IGEs (Moore et al. 1997; Bleakley et al. 2010). The interactio ...
Thermal adaptation and ecological speciation
... the thermal stability of enzymes (e.g. Angilletta 2009). It is hard to see how such differences could be important for mate choice, where phenotypic divergence is likely to play a greater role than cryptic genetic differences (Stelkens & Seehausen 2009). One possibility is that mate choice is based ...
... the thermal stability of enzymes (e.g. Angilletta 2009). It is hard to see how such differences could be important for mate choice, where phenotypic divergence is likely to play a greater role than cryptic genetic differences (Stelkens & Seehausen 2009). One possibility is that mate choice is based ...
Koinophilia - Current Science
... The ‘beauty is average’ hypothesis should have strengthened the notion of koinophilia. But Perrett and co-workers7 appear to have found evidence that the average face is not the most attractive face. They found that they could create a face that was more attractive than the average face by averaging ...
... The ‘beauty is average’ hypothesis should have strengthened the notion of koinophilia. But Perrett and co-workers7 appear to have found evidence that the average face is not the most attractive face. They found that they could create a face that was more attractive than the average face by averaging ...
Some important factors affecting fertility in sheep
... Abstract: Efficiency of sheep production is conditioned by fertility. According to some authors number of offspring obtained per lambing is more important than gain of weight. Genetic relationships involving reproductive traits were seldom studied. Reproductive traits have low heritabilities, a disc ...
... Abstract: Efficiency of sheep production is conditioned by fertility. According to some authors number of offspring obtained per lambing is more important than gain of weight. Genetic relationships involving reproductive traits were seldom studied. Reproductive traits have low heritabilities, a disc ...
Artificial Selection: How Humans Can Sway Nature
... Species, where he explained there are certain characteristics that help an animal survive, such as a sharp beak that allows birds in the Galapagos Islands to better find and eat their food. These sharp‐beaked birds survived long enough to reproduce, and their offspring had sharp beaks too. Eventu ...
... Species, where he explained there are certain characteristics that help an animal survive, such as a sharp beak that allows birds in the Galapagos Islands to better find and eat their food. These sharp‐beaked birds survived long enough to reproduce, and their offspring had sharp beaks too. Eventu ...
The danger of applying the breeder`s equation in observational
... what genes will be represented in the next generation. For instance, in scenario 1, individuals with genes that promote large phenotypic values (red upward-pointing triangles) will be increasingly represented in future generations, given that the scenario illustrated in the top panels exists. In con ...
... what genes will be represented in the next generation. For instance, in scenario 1, individuals with genes that promote large phenotypic values (red upward-pointing triangles) will be increasingly represented in future generations, given that the scenario illustrated in the top panels exists. In con ...
Predicting Microevolutionary Responses to Directional Selection on
... It would appear to be a straightforward matter to measure both responses are well predicted. This allows us to conclude a group of individuals before and again after selection, and that, to a first approximation, targets of selection have been then measure the offspring of the selected sample at the ...
... It would appear to be a straightforward matter to measure both responses are well predicted. This allows us to conclude a group of individuals before and again after selection, and that, to a first approximation, targets of selection have been then measure the offspring of the selected sample at the ...
What does Drosophila genetics tell us about speciation?
... reproductive isolation triggers the origin of sexual species. Because reproductive isolation is not the same as speciation, we need to decide which components of reproductive isolation are important. We must infer the sequence of genetic changes, and their relative effects on the stability of diverg ...
... reproductive isolation triggers the origin of sexual species. Because reproductive isolation is not the same as speciation, we need to decide which components of reproductive isolation are important. We must infer the sequence of genetic changes, and their relative effects on the stability of diverg ...
How much do genetic covariances alter the rate of adaptation?
... variance in one or more directions can occur even when all genetic correlations are less than unity in magnitude when nO2. If one of these directions with no genetic variation matches the direction of selection (b), then there will be no evolution. In such a case, we can say that genetic correlation ...
... variance in one or more directions can occur even when all genetic correlations are less than unity in magnitude when nO2. If one of these directions with no genetic variation matches the direction of selection (b), then there will be no evolution. In such a case, we can say that genetic correlation ...
Natural Selection in Relation to Complexity
... other than one trait among many that have been episodically modified in a past period of coevolution of these populations. It would be misleading, then, to state that beak size here ‘‘has evolved’’ in the sense of ‘‘the evolution of beaks’’ being the label of an actual process that took place in nat ...
... other than one trait among many that have been episodically modified in a past period of coevolution of these populations. It would be misleading, then, to state that beak size here ‘‘has evolved’’ in the sense of ‘‘the evolution of beaks’’ being the label of an actual process that took place in nat ...
Using Artificial Selection to Understand Plastic Plant Phenotypes1
... The plasticity of any given trait, which has a genetic basis and which may or may not be adaptive, can intensify or attenuate evolved responses, and can itself evolve in response to selection depending on the scale of spatial or temporal heterogeneity. To investigate the complex function and evoluti ...
... The plasticity of any given trait, which has a genetic basis and which may or may not be adaptive, can intensify or attenuate evolved responses, and can itself evolve in response to selection depending on the scale of spatial or temporal heterogeneity. To investigate the complex function and evoluti ...
Why do individuals 4 and 5 have G rather than B
... on the order of births, selection would not determine that the fourth member stems from 3 (rather than 2). So for selection to explain why the fourth member is an offspring of 3, it may seem as if we must endorse the unrealistically strong assumption that selection is an all-ornothing affair.8 Howev ...
... on the order of births, selection would not determine that the fourth member stems from 3 (rather than 2). So for selection to explain why the fourth member is an offspring of 3, it may seem as if we must endorse the unrealistically strong assumption that selection is an all-ornothing affair.8 Howev ...
Speciation by Natural and Sexual Selection: Models and Experiments.
... Several kinds of disruptive selection can lead to speciation (table 1, sec. I). Perhaps the simplest is spatial variation in fitness, as emphasized by proponents of allopatric speciation (Mayr 1963). A second way to generate persistent disruptive selection is frequency dependence, as when population ...
... Several kinds of disruptive selection can lead to speciation (table 1, sec. I). Perhaps the simplest is spatial variation in fitness, as emphasized by proponents of allopatric speciation (Mayr 1963). A second way to generate persistent disruptive selection is frequency dependence, as when population ...
Quantitative Genetics and Evolution
... gene with large allelic effects on phenotype, and almost no environmental influence. Such phenotypes are qualitative in nature (they are verbally described), and are suitable to standard genetic analysis. In contrast, gradualism assumed that evolutionary change is gradual, and that it is a consequen ...
... gene with large allelic effects on phenotype, and almost no environmental influence. Such phenotypes are qualitative in nature (they are verbally described), and are suitable to standard genetic analysis. In contrast, gradualism assumed that evolutionary change is gradual, and that it is a consequen ...
speciation - Cameron University
... many possible courses of evolution are simply not an option once certain paths have been followed. Ardent adaptationists, such as Richard Dawkins (1976), feel that the idea of constraints is badly overemphasized. For an amusing interchange see the back-to-back reviews of each other’s books by Gould ...
... many possible courses of evolution are simply not an option once certain paths have been followed. Ardent adaptationists, such as Richard Dawkins (1976), feel that the idea of constraints is badly overemphasized. For an amusing interchange see the back-to-back reviews of each other’s books by Gould ...
Ecological Speciation Among Blue Holes in Mosquitofish
... mechanism can occur in any geographical context, and does not require selection to directly favor reproductive isolation (i.e., reinforcement). Theory suggests that divergent natural selection between environments might often result in speciation as a by-product, however only a handful of examples w ...
... mechanism can occur in any geographical context, and does not require selection to directly favor reproductive isolation (i.e., reinforcement). Theory suggests that divergent natural selection between environments might often result in speciation as a by-product, however only a handful of examples w ...
"Parental Care and Investment". - DIGITAL.CSIC, el repositorio
... The aforementioned hypotheses have the underlying assumption that differences in gamete size and initial investment are sufficient to explain why one sex competes and the other cares. However, since every offspring has only a single mother and a single father, the total number of matings in which males ...
... The aforementioned hypotheses have the underlying assumption that differences in gamete size and initial investment are sufficient to explain why one sex competes and the other cares. However, since every offspring has only a single mother and a single father, the total number of matings in which males ...
Why We Take Risks - University of Oregon
... Charles Darwin is of course best known for his theory of evolution by natural selection. But in his 1872 book, The Descent of Man, he developed an equally important idea, largely ignored until the mid-20th century. Evolution by sexual selection holds that genetic change is also influenced by the abi ...
... Charles Darwin is of course best known for his theory of evolution by natural selection. But in his 1872 book, The Descent of Man, he developed an equally important idea, largely ignored until the mid-20th century. Evolution by sexual selection holds that genetic change is also influenced by the abi ...
population genetics - McGraw Hill Higher Education
... such a gene may display a novel function and can then be acted upon by evolutionary mechanisms. ...
... such a gene may display a novel function and can then be acted upon by evolutionary mechanisms. ...
Ecological genetics of floral evolution
... version of genetic covariances) result from pleiotropy (one gene locus affects variation in multiple traits) or gametic-phase disequilibrium (nonrandom association between alleles at distinct loci, each of which affect variation in one trait of interest). Such correlations have two important consequ ...
... version of genetic covariances) result from pleiotropy (one gene locus affects variation in multiple traits) or gametic-phase disequilibrium (nonrandom association between alleles at distinct loci, each of which affect variation in one trait of interest). Such correlations have two important consequ ...
The speed of ecological speciation
... generations. Linkage disequilibrium then builds up between traits influencing adaptation and traits influencing mate choice – because hybrids have low fitness owing to their lack of adaptation to either parental environment. Almost perfect assortative mating can arise in a few hundred generations, e ...
... generations. Linkage disequilibrium then builds up between traits influencing adaptation and traits influencing mate choice – because hybrids have low fitness owing to their lack of adaptation to either parental environment. Almost perfect assortative mating can arise in a few hundred generations, e ...
A general model of the relation between phenotypic selection and
... predicted if there is additional selection on a genetically correlated trait (e.g. Lerner and Dempster, 195 1; Falconer, 198 1). Natural selection can only be adequately described if all the relevant traits and constraints among traits are taken into account (Lande and Arnold, 1983; Burger, 1986; Ar ...
... predicted if there is additional selection on a genetically correlated trait (e.g. Lerner and Dempster, 195 1; Falconer, 198 1). Natural selection can only be adequately described if all the relevant traits and constraints among traits are taken into account (Lande and Arnold, 1983; Burger, 1986; Ar ...
Mate choice
Mate choice or intersexual selection is an evolutionary process in which selection, normally of a male mate by a female chooser, is dependent on the attractiveness of his phenotypic traits. It is one of two components of sexual selection (the other being intrasexual selection). Charles Darwin first introduced his ideas on sexual selection in 1871 but they were initially rejected. Ronald Fisher then developed the idea in his 1915 paper The evolution of sexual preference outlined the Fisherian runaway theory in 1930. Advances in genetic and molecular biology techniques have accompanied major progress in this field recently.Five currently recognized mechanisms, which can co-occur, and for each of which there are many examples, explain the evolution of mate choice.In systems where mate choice exists, one sex is competitive with same-sex members and the other sex is choosy (selective when it comes to picking individuals to mate with). In most species, females are the choosy sex that discriminate amongst competitive males but there are several examples of reversed roles (see below).