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... evolve wildly elaborate structures in the competition to better stimulate females. Runaway sexual selection is not likely to be controlled by natural selection for the most part, because genitalic structures rarely impede an organism outside of its reproductive context (Eberhard 1985). The second me ...
... evolve wildly elaborate structures in the competition to better stimulate females. Runaway sexual selection is not likely to be controlled by natural selection for the most part, because genitalic structures rarely impede an organism outside of its reproductive context (Eberhard 1985). The second me ...
The Role of Coloration in Mate Choice and Sexual
... lower marginal costs per unit elaboration of these traits (Grafen, 1990). Perhaps due to the apparent simplicity of this prediction, considerable effort has gone into testing it across a range of animals and traits, including many color-based sexual signals (e.g., Johnsen et al., 2003; Lim and Li, 2 ...
... lower marginal costs per unit elaboration of these traits (Grafen, 1990). Perhaps due to the apparent simplicity of this prediction, considerable effort has gone into testing it across a range of animals and traits, including many color-based sexual signals (e.g., Johnsen et al., 2003; Lim and Li, 2 ...
Aerial performance of stalk-eyed ¯ies that differ in eye span
... a given sex, usually males, experience a mating advantage through the mechanisms of female choice or male competition. Almost all recent theoretical models assume that elaborate male secondary sexual characteristics are costly to produce and to maintain (e.g., Grafen 1990a, b; Pomiankowski et al. 19 ...
... a given sex, usually males, experience a mating advantage through the mechanisms of female choice or male competition. Almost all recent theoretical models assume that elaborate male secondary sexual characteristics are costly to produce and to maintain (e.g., Grafen 1990a, b; Pomiankowski et al. 19 ...
chapter 1 - WordPress.com
... The encephalization of mammals, and primates in particular, has been the focal point of many studies (Pilbeam & Gould 1974; Roth & Dicke 2005; Williams 2002;) over the past four decades. A great deal of time and energy has gone into generating and testing hypotheses based on the idea that the extrem ...
... The encephalization of mammals, and primates in particular, has been the focal point of many studies (Pilbeam & Gould 1974; Roth & Dicke 2005; Williams 2002;) over the past four decades. A great deal of time and energy has gone into generating and testing hypotheses based on the idea that the extrem ...
variation in mate choice and mating preferences: a review of causes
... preferences can be distinguished : () ‘ preference functions ’ – the order with which an individual ranks prospective mates and () ‘ choosiness ’ – the effort an individual is prepared to invest in mate assessment. Patterns of mate choices can be altered by changing the costs of choosiness without ...
... preferences can be distinguished : () ‘ preference functions ’ – the order with which an individual ranks prospective mates and () ‘ choosiness ’ – the effort an individual is prepared to invest in mate assessment. Patterns of mate choices can be altered by changing the costs of choosiness without ...
A Study of the Second Digit to Forth Digit Ratio targeting Taekwondo
... The 2D:4D ratio is one of the typical indicators that represent sexually dimorphic traits, and generally, in males, an index finger is shorter than a ring finger (2D:4D<1) and in females, an index finger is the same as or longer than a ring finger (2D:4D ≥ 1). An experimental study using animals als ...
... The 2D:4D ratio is one of the typical indicators that represent sexually dimorphic traits, and generally, in males, an index finger is shorter than a ring finger (2D:4D<1) and in females, an index finger is the same as or longer than a ring finger (2D:4D ≥ 1). An experimental study using animals als ...
Polyandry as a mediator of sexual selection before and after mating
... is the ratio (m : f ) or proportion (m/m þ f ) of males and females that are ready to mate in a population at any one time [4,9]. In many species, both sexes show some level of competition for mating opportunities. However, when the relative number of opposite sex individuals that are ready to mate ...
... is the ratio (m : f ) or proportion (m/m þ f ) of males and females that are ready to mate in a population at any one time [4,9]. In many species, both sexes show some level of competition for mating opportunities. However, when the relative number of opposite sex individuals that are ready to mate ...
Sexual segregation in ungulates: a comparative test of three
... the breeding season. It is important for our understanding of the evolution of sociality to find out why sexual segregation is so widespread not only in ungulates but also in other mammals. Sexual body size dimorphism was proposed as a central factor in the evolution of sexual segregation in ungulat ...
... the breeding season. It is important for our understanding of the evolution of sociality to find out why sexual segregation is so widespread not only in ungulates but also in other mammals. Sexual body size dimorphism was proposed as a central factor in the evolution of sexual segregation in ungulat ...
Possible ecological risks of transgenic organism release when
... 10). Growth enhancements of up to several times that of wild type have been obtained, with growth advantages persisting throughout adulthood in some fish species (8, 11). In many animal species, including fish, body size is an important determinant of differential mating success (sexual selection) t ...
... 10). Growth enhancements of up to several times that of wild type have been obtained, with growth advantages persisting throughout adulthood in some fish species (8, 11). In many animal species, including fish, body size is an important determinant of differential mating success (sexual selection) t ...
2D:4D
... Indeed, Total Aggression was positively associated with the number of sexual partners, and for males, Physical and Total Aggression were positively associated with spatial abilities – the more aggression reported, the higher the spatial scores. Interestingly, this relationship was reversed for the f ...
... Indeed, Total Aggression was positively associated with the number of sexual partners, and for males, Physical and Total Aggression were positively associated with spatial abilities – the more aggression reported, the higher the spatial scores. Interestingly, this relationship was reversed for the f ...
Genetic Correlations with Floral Display Lead to Sexual Dimorphism
... comparisons of multiple dioecious species show that higher reproductive effort by females often is associated with less growth, higher photosynthetic rates, delayed or less frequent reproduction, earlier death, and spatial segregation, with males more frequent in low-resource sites (Delph 1999; Obes ...
... comparisons of multiple dioecious species show that higher reproductive effort by females often is associated with less growth, higher photosynthetic rates, delayed or less frequent reproduction, earlier death, and spatial segregation, with males more frequent in low-resource sites (Delph 1999; Obes ...
sex-specific growth in the european sha g
... (Amundsen & Stockland 1988 ; Velando 1997) . (Velando 1997) . Fifty-six nesting sites were tagBecause this species is clearly dimorphic in size ged beginning in 1994 and visited periodically (males are 22% heavier than females during the thereafter. The fieldwork was carried out in colobreeding seas ...
... (Amundsen & Stockland 1988 ; Velando 1997) . (Velando 1997) . Fifty-six nesting sites were tagBecause this species is clearly dimorphic in size ged beginning in 1994 and visited periodically (males are 22% heavier than females during the thereafter. The fieldwork was carried out in colobreeding seas ...
Aphrodisiac Properties Of Turnera Diffusa
... groups (n=4 per condition) observed limited the power of the statistical methods. There was a large degree of variation within groups. This may be, in part, due to variable distribution of both control and damiana injections among individuals. It was observed that sometimes the fluid seemed to dissi ...
... groups (n=4 per condition) observed limited the power of the statistical methods. There was a large degree of variation within groups. This may be, in part, due to variable distribution of both control and damiana injections among individuals. It was observed that sometimes the fluid seemed to dissi ...
Reprint
... not depend on which males they mate with but on how many they mate with. Although these male “phenotypeindependent” costs are probably common, there are other cases where the costs to females do depend on the phenotypes of their mating partners because some male phenotypes are more costly to mate wi ...
... not depend on which males they mate with but on how many they mate with. Although these male “phenotypeindependent” costs are probably common, there are other cases where the costs to females do depend on the phenotypes of their mating partners because some male phenotypes are more costly to mate wi ...
Does tusker`s attacks on female elephants are indicating towards
... 1968, at Hatpata, a number of elephant groups were feeding in an open area in the mid-after-noon hours. At 17:15 h, one male, who was also feeding in the same area, approached one of the groups. He made trunk to genitalia contact with one female and moved on toward another. Later on, when he moved t ...
... 1968, at Hatpata, a number of elephant groups were feeding in an open area in the mid-after-noon hours. At 17:15 h, one male, who was also feeding in the same area, approached one of the groups. He made trunk to genitalia contact with one female and moved on toward another. Later on, when he moved t ...
Adaptations to sexual selection and sexual conflict
... not yet run over a sufficiently long period of evolutionary time or that not all relevant traits have been studied (see below for discussion of further pitfalls). There is also considerable interest in using selection techniques to study rates of adaptation. Theory states that sexual selection can s ...
... not yet run over a sufficiently long period of evolutionary time or that not all relevant traits have been studied (see below for discussion of further pitfalls). There is also considerable interest in using selection techniques to study rates of adaptation. Theory states that sexual selection can s ...
THE EVOLUTION OF MALE TRAITS IN SOCIAL INSECTS Jacobus J
... phases is less clear when males sit on branches and pounce on females passing by and remain attached to them during the rest of the dispersal flight (91, 118). In other termites, females call after a dispersal flight (91). Social Hymenoptera therefore usually have a single position in the parameter ...
... phases is less clear when males sit on branches and pounce on females passing by and remain attached to them during the rest of the dispersal flight (91, 118). In other termites, females call after a dispersal flight (91). Social Hymenoptera therefore usually have a single position in the parameter ...
Lack of Assortative Mating Between Incipient Species of Stickleback
... species provide an excellent opportunity to investigate the importance of different reproductive isolating barriers because the nature of the divergence is not obscured by differences which have accumulated after reproductive isolation evolved. In this respect, stickleback species pairs (e.g., limne ...
... species provide an excellent opportunity to investigate the importance of different reproductive isolating barriers because the nature of the divergence is not obscured by differences which have accumulated after reproductive isolation evolved. In this respect, stickleback species pairs (e.g., limne ...
Sample pages 4 PDF
... None before him has arranged all the products of nature with such lucidity.’ A crucial difference between the crocodilia and most other species is that their sex is determined by the incubation temperature of the egg during gestation, basically females at low temperatures and males at high temperatu ...
... None before him has arranged all the products of nature with such lucidity.’ A crucial difference between the crocodilia and most other species is that their sex is determined by the incubation temperature of the egg during gestation, basically females at low temperatures and males at high temperatu ...
Sexual selection and the detection of ecological speciation
... males signal and females choose. Following previous work on ecological speciation (Rundle et al., 2000; Nosil et al., 2002; Boughman et al., 2005), we consider ecological pre-mating isolation to be signalled by non-random mating that leads to a bias against individuals from different environments. S ...
... males signal and females choose. Following previous work on ecological speciation (Rundle et al., 2000; Nosil et al., 2002; Boughman et al., 2005), we consider ecological pre-mating isolation to be signalled by non-random mating that leads to a bias against individuals from different environments. S ...
Female Polymorphism, Frequency Dependence, and Rapid
... exposed to male mating attempts and male mating harassment, may be above the optimal female mating rate (Arnqvist and Nilsson 2000). Most laboratory experiments on the fitness effects of female mating rates have revealed that female longevity declines for each additional mating, whereas an optimal ( ...
... exposed to male mating attempts and male mating harassment, may be above the optimal female mating rate (Arnqvist and Nilsson 2000). Most laboratory experiments on the fitness effects of female mating rates have revealed that female longevity declines for each additional mating, whereas an optimal ( ...
Phenotypic correlates of male reproductive success in western gorillas
... Parnell, 2002a; Levrero et al., 2004; Robbins et al., 2009). Infanticide by outsider males is considered an extreme form of coercion because it may induce the female to leave the resident silverback who failed to defend her offspring (Fossey, 1984; Watts, 1989). Offspring survival has accounted for ...
... Parnell, 2002a; Levrero et al., 2004; Robbins et al., 2009). Infanticide by outsider males is considered an extreme form of coercion because it may induce the female to leave the resident silverback who failed to defend her offspring (Fossey, 1984; Watts, 1989). Offspring survival has accounted for ...
Current Issues – Perspectives and Reviews
... populations has uncovered an anomaly that cannot easily be aligned with the Darwinian paradigm of the promiscuous male and the choosy, essentially monogamous female (Darwin 1871; Williams 1966; Trivers 1972). As a consequence, the last decade has seen a proliferation of empirical and theoretical inv ...
... populations has uncovered an anomaly that cannot easily be aligned with the Darwinian paradigm of the promiscuous male and the choosy, essentially monogamous female (Darwin 1871; Williams 1966; Trivers 1972). As a consequence, the last decade has seen a proliferation of empirical and theoretical inv ...
Spatio-temporal segregation by sex of Chiffchaffs Phylloscopus
... (September 2003–March 2010). Wing lengths were longer in winter than in autumn and during spring migration, indicating that males were proportionally more abundant during the winter. By contrast, wing lengths did not differ between capture habitats, indicating that the sex ratio did not depend on ha ...
... (September 2003–March 2010). Wing lengths were longer in winter than in autumn and during spring migration, indicating that males were proportionally more abundant during the winter. By contrast, wing lengths did not differ between capture habitats, indicating that the sex ratio did not depend on ha ...
SEXUAL SELECTION AND THE DESCENT OF MAN 1871-1971
... attract or arouse females. The 21 per cent who failed to reproduce showed no disinterest in trying to copulate, only an inability to be accepted. (3) A female's reproductive success did not increase much, if any, after the first copulation and not at all after the second; most females were uninteres ...
... attract or arouse females. The 21 per cent who failed to reproduce showed no disinterest in trying to copulate, only an inability to be accepted. (3) A female's reproductive success did not increase much, if any, after the first copulation and not at all after the second; most females were uninteres ...