convergence, recurrence and diversification of
... conjugate form, and (3) examine patterns of convergence, recurrence and loss of conjugation, and sperm heteromorphism. We also test hypotheses of correlated evolution among sperm traits including conjugation, head shape, sperm length, and heteromorphism. Head shape might affect the propensity of spe ...
... conjugate form, and (3) examine patterns of convergence, recurrence and loss of conjugation, and sperm heteromorphism. We also test hypotheses of correlated evolution among sperm traits including conjugation, head shape, sperm length, and heteromorphism. Head shape might affect the propensity of spe ...
Assortative Fertilization in the Elegans-Group of
... 1980). Two different gene complexes have evolved due to ecological differences in their mating sites. The D. grimshawi-Maui complex populations have a polymorphic inversion sequence on chromosome 4 and lay their eggs on a variety of plants. Other D. grimshawi populations retain the primary ancestral ...
... 1980). Two different gene complexes have evolved due to ecological differences in their mating sites. The D. grimshawi-Maui complex populations have a polymorphic inversion sequence on chromosome 4 and lay their eggs on a variety of plants. Other D. grimshawi populations retain the primary ancestral ...
genetic differentiation by sexual conflict
... Sexual conflict—a conflict between the evolutionary interests of individuals of the two sexes (Parker 1979, 2006)—occurs when the interests of the sexes differ with regard to certain characteristics of reproduction. For example, male fitness typically increases with mating rate, but a too high matin ...
... Sexual conflict—a conflict between the evolutionary interests of individuals of the two sexes (Parker 1979, 2006)—occurs when the interests of the sexes differ with regard to certain characteristics of reproduction. For example, male fitness typically increases with mating rate, but a too high matin ...
Mating behavior and the evolution of sperm design
... and attempting to engage in sperm donation. Matings that are disadvantageous to the female function therefore are more likely to occur in simultaneous hermaphrodites, shifting sexual selection and sexual conflict from the pre- to the postcopulatory stage. This argument assumes that multiple mating in ...
... and attempting to engage in sperm donation. Matings that are disadvantageous to the female function therefore are more likely to occur in simultaneous hermaphrodites, shifting sexual selection and sexual conflict from the pre- to the postcopulatory stage. This argument assumes that multiple mating in ...
Sexual selection and temporal phenotypic variation in a damselfly
... Moreover, because a female must bend her abdomen up to engage the male’s secondary genitalia, males cannot force females to copulate. A female rejects a male with whom she is in tandem by moving about roughly until the male releases her (Fincke, 1984). In this study, we cannot distinguish between th ...
... Moreover, because a female must bend her abdomen up to engage the male’s secondary genitalia, males cannot force females to copulate. A female rejects a male with whom she is in tandem by moving about roughly until the male releases her (Fincke, 1984). In this study, we cannot distinguish between th ...
Book Reviews 103 Wertheimer`s analysis clearly
... women vary considerably in their reported rates of orgasm, with a small percentage reporting never having had an orgasm from intercourse. Finally, masturbation in women, and both masturbation and homosexual interactions in non-human primate females, appear more likely to elicit orgasm than does hete ...
... women vary considerably in their reported rates of orgasm, with a small percentage reporting never having had an orgasm from intercourse. Finally, masturbation in women, and both masturbation and homosexual interactions in non-human primate females, appear more likely to elicit orgasm than does hete ...
Lack of Assortative Mating Between Incipient Species of Stickleback
... into two broad groups: premating barriers which act to limit the formation of zygotes, and postmating barriers which act to reduce the fitness of hybrid offspring. Assortative mating, the occurrence of matings within forms more often than between forms, can be the outcome of multiple different prema ...
... into two broad groups: premating barriers which act to limit the formation of zygotes, and postmating barriers which act to reduce the fitness of hybrid offspring. Assortative mating, the occurrence of matings within forms more often than between forms, can be the outcome of multiple different prema ...
Behavioral Ecology
... from high-predation environments might express a reduced preference for orange fin coloration or even a preference for the less orange fin typical in high-predation populations. Considering that prior work has demonstrated that females from different predation regimes exhibit divergent preferences f ...
... from high-predation environments might express a reduced preference for orange fin coloration or even a preference for the less orange fin typical in high-predation populations. Considering that prior work has demonstrated that females from different predation regimes exhibit divergent preferences f ...
Johnson, K. P. 1999. The evolution of bill coloration and plumage
... this is the case. Females of species with bright male bill coloration often have colored bills (10 out of 14 species). This could be due to a genetic correlation between males and females which causes bill coloration to be present in females because it is being selected for in males (Fisher, 1930; L ...
... this is the case. Females of species with bright male bill coloration often have colored bills (10 out of 14 species). This could be due to a genetic correlation between males and females which causes bill coloration to be present in females because it is being selected for in males (Fisher, 1930; L ...
The evolution of animal genitalia: distinguishing between
... genitalic evolution. However, since this program focuses on current evolutionary processes rather than the results of past evolutionary events, it should be viewed as a necessary complement, rather as an alternative, to other approaches. In other words, the program is primarily concerned with the ma ...
... genitalic evolution. However, since this program focuses on current evolutionary processes rather than the results of past evolutionary events, it should be viewed as a necessary complement, rather as an alternative, to other approaches. In other words, the program is primarily concerned with the ma ...
Host-shift effects on mating behavior and
... facultative aphagous and are able to mate and complete their life cycles using only metabolic water and resources acquired during larval development. The pattern of courtship activities in this species does not include specific rituals or acoustic signals. Males chase and then mount females in orien ...
... facultative aphagous and are able to mate and complete their life cycles using only metabolic water and resources acquired during larval development. The pattern of courtship activities in this species does not include specific rituals or acoustic signals. Males chase and then mount females in orien ...
intraspecific variation in sexual isolation in the
... of the two-hour assay reconfirms the large difference in interspecific sexual isolation between these strains. Mating frequencies when NV Idaho males are crossed to NL Idaho and NL California females are 57.0% and 2.6%, respectively (Table 4). We also analyzed the data to look for evidence of incipi ...
... of the two-hour assay reconfirms the large difference in interspecific sexual isolation between these strains. Mating frequencies when NV Idaho males are crossed to NL Idaho and NL California females are 57.0% and 2.6%, respectively (Table 4). We also analyzed the data to look for evidence of incipi ...
Omtentafråga - Studentportalen
... selective regimes during periods in allopatry or because they have been exposed to strong competition in sympatry and therefore diverged in one or several ecologically important trait (e.g. the example of beak size in the finches I showed on the black board). Hybrids typically have an intermediate p ...
... selective regimes during periods in allopatry or because they have been exposed to strong competition in sympatry and therefore diverged in one or several ecologically important trait (e.g. the example of beak size in the finches I showed on the black board). Hybrids typically have an intermediate p ...
Postcopulatory sexual selection
... of males. Among their other functions, these substances deactivate sperm that are already stored in the reproductive tract of the female (offence), and act as an anti-aphrodisiac, discouraging the female from copulating with other males (defence)22. Sperm competition therefore results in intense mal ...
... of males. Among their other functions, these substances deactivate sperm that are already stored in the reproductive tract of the female (offence), and act as an anti-aphrodisiac, discouraging the female from copulating with other males (defence)22. Sperm competition therefore results in intense mal ...
The limits of sexual conflict in the narrow sense
... with resistance, the evolutionary origins, dynamics and consequences of female mating behaviour are obscured. Mating biases have been used as a modelling tool that allowed workers to concentrate on the outcome of sexual interactions rather than, to quote one reviewer, in the ‘often unknowable detail ...
... with resistance, the evolutionary origins, dynamics and consequences of female mating behaviour are obscured. Mating biases have been used as a modelling tool that allowed workers to concentrate on the outcome of sexual interactions rather than, to quote one reviewer, in the ‘often unknowable detail ...
6 - BHU
... quick decline of mutant flies from subsequent generations. They suggested that the elimination of white eye gene in about twenty five generations was caused due to inefficiency of white males in mating. They also observed that for every 100 mating of red males only 75 white males succeeded in D. mel ...
... quick decline of mutant flies from subsequent generations. They suggested that the elimination of white eye gene in about twenty five generations was caused due to inefficiency of white males in mating. They also observed that for every 100 mating of red males only 75 white males succeeded in D. mel ...
Sexual selection promotes hybridization between Pecos pupfish
... Cyprinodon pecosensis is endemic to the southern Pecos River drainage of New Mexico and Texas (Echelle & Echelle, 1978). Cyprinodon variegatus has a much broader geographic range, stretching from the coast of Massachu2 setts to the Yucatán Peninsula (Lee et al. 1980); the species is widely introduc ...
... Cyprinodon pecosensis is endemic to the southern Pecos River drainage of New Mexico and Texas (Echelle & Echelle, 1978). Cyprinodon variegatus has a much broader geographic range, stretching from the coast of Massachu2 setts to the Yucatán Peninsula (Lee et al. 1980); the species is widely introduc ...
Sexual-Selection Models for Exaggerated Traits
... They were given a choice of two appropriately larger normal males of about the same size. We wanted to determine female choice first when restrained by a barrier and then ask whether the same female could successfully mate with the unrestrained male of her choice. On the first day, the female could ...
... They were given a choice of two appropriately larger normal males of about the same size. We wanted to determine female choice first when restrained by a barrier and then ask whether the same female could successfully mate with the unrestrained male of her choice. On the first day, the female could ...
Female preference for fly song: playback
... not obligatory, part of courtship (Ewing 1964; Burnet et al. 1971). Only in three species, D. montana, D. ezoana (Hoikkala 1988; Liimatainen et al. 1992) and D. busckii (Bixler et al. 1992) have females been found to refuse to mate in the absence of song. Most other studies of fly song have emphasiz ...
... not obligatory, part of courtship (Ewing 1964; Burnet et al. 1971). Only in three species, D. montana, D. ezoana (Hoikkala 1988; Liimatainen et al. 1992) and D. busckii (Bixler et al. 1992) have females been found to refuse to mate in the absence of song. Most other studies of fly song have emphasiz ...
sexually transmitted disease and the evolution of mating
... Thrall et al. (1997) presented one of the first formal models of optimal mating behavior in the presence of STD (see Discussion for other models). They assumed that females benefit from multiple matings through reducing the risk of infertility, but that females also risk catching the disease when ma ...
... Thrall et al. (1997) presented one of the first formal models of optimal mating behavior in the presence of STD (see Discussion for other models). They assumed that females benefit from multiple matings through reducing the risk of infertility, but that females also risk catching the disease when ma ...
Word - Understanding Evolution
... direct components of fitness are survival/reproductive benefits and costs experienced by the individual of interest and that indirect components of fitness are survival/reproductive benefits and costs experienced by the individual’s offspring (or relatives). Direct selection is just selection acting ...
... direct components of fitness are survival/reproductive benefits and costs experienced by the individual of interest and that indirect components of fitness are survival/reproductive benefits and costs experienced by the individual’s offspring (or relatives). Direct selection is just selection acting ...
Sex and Reproductive Success
... n the previous chapter, we treated those components of fitness, age-specific schedules of survival, and female reproduction that affect the increase or decrease in numbers of individual organisms with different genotypes, and indeed of populations. Changes in the relative numbers of variant alleles, ...
... n the previous chapter, we treated those components of fitness, age-specific schedules of survival, and female reproduction that affect the increase or decrease in numbers of individual organisms with different genotypes, and indeed of populations. Changes in the relative numbers of variant alleles, ...
The Importance Of Female Choice - Chapman University Digital
... genetic predispositions are partly or completely responsible for the development of these traits, they can be passed on from parent to offspring. In his text On the of Species by Means ofNatural Selection, Charles Darwin (1859) puzzled over the existence of sex differences in behavior and morphology ...
... genetic predispositions are partly or completely responsible for the development of these traits, they can be passed on from parent to offspring. In his text On the of Species by Means ofNatural Selection, Charles Darwin (1859) puzzled over the existence of sex differences in behavior and morphology ...
Sexual conflict
Sexual conflict or sexual antagonism occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly over the mode and frequency of mating, potentially leading to an evolutionary arms race between males and females. For instance, males may benefit from multiple matings, while multiple matings may harm or endanger females. The development of an evolutionary arms race can also be seen in the chase-away sexual selection model, which places inter-sexual conflicts in the context of secondary sexual characteristic evolution, sensory exploitation, and female resistance. According to chase-away selection, continuous sexual conflict creates an environment in which mating frequency and male secondary sexual trait development are somewhat in step with the female’s degree of resistance. It has primarily been studied in animals, though it can in principle apply to any sexually reproducing organism, such as plants and fungi.Sexual conflict/antagonism can be in two forms:Interlocus sexual conflict is the interaction of a set of antagonistic alleles at one or more loci in males and females. An example is conflict over mating rates. Males frequently have a higher optimal mating rate than females because in most animal species, they invest fewer resources in offspring than their female counterparts. Therefore, males have numerous adaptations to induce females to mate with them. Another well-documented example of inter-locus sexual conflict is the seminal fluid of Drosophila melanogaster, which up-regulates females' egg-laying rate and reduces her desire to re-mate with another male (serving the male's interests), but also shortens the female's lifespan reducing her fitness.Intralocus sexual conflict This kind of conflict represents a tug of war between natural selection on both sexes and sexual selection on one sex. For example, the bill color in Zebra finches etc. Ornamentation could be costly to produce, it is important in mate choice but also makes an individual vulnerable to predators, the alleles for such phenotypic traits are under antagonistic selection and this conflict is resolved via elaborate sexual dimorphism thus maintaining sexually antagonistic alleles in the population. Evidence indicates that intralocus conflict may be an important constraint in the evolution of many traits.Sexual conflict may lead to antagonistic co-evolution, in which one sex (usually male) evolves a favorable trait that is offset by a countering trait in the other sex. Similarly, interlocus sexual conflict can be the result of what is called a perpetual cycle. The perpetual cycle begins with the traits that favor male reproductive competition, which eventually manifests into male persistence. These favorable traits will cause a reduction in the fitness of females due to their persistence. Following this event, females may develop a counter-adaptation, that is, a favorable trait that reduces the direct costs implemented by males. This is known as female resistance. After this event, females' fitness depression decreases, and the cycle starts again. Interlocus sexual conflict reflects interactions among mates to achieve their optimal fitness strategies and can be explained through evolutionary concepts.Sensory exploitation by males is one mechanism that involves males attempting to overcome female reluctance. It can result in chase-away selection, which then leads to a co-evolutionary arms race. There are also other mechanisms involved in sexual conflict such as traumatic insemination, forced copulation, penis fencing, love darts and others.Female resistance traditionally includes reducing negative effects to mechanisms implemented by males, but outside the norm may include sexual cannibalism, increased fitness in females on offspring and increased aggression to males.Animal species that are not in a state of sexual conflict are more likely to be in sync to the male dominance hierarchy as the females are more docile in these organizations such as wolves, common rabbits and crocodiles. Others, such as spiders, ants and orcas are female-dominated. Some regard sexual conflict as a subset of sexual selection (which was traditionally regarded as mutualistic), while others suggest it is a separate evolutionary phenomenon.