Positive feedback in the transition from sexual reproduction to
... demographic stochasticity, some females may fail to find a mate. Because unmated females can only produce daughters through tychoparthenogenesis, the population sex ratio becomes more female-biased, resulting in a yet larger proportion of females not finding mates. Thus, the strength of selection fo ...
... demographic stochasticity, some females may fail to find a mate. Because unmated females can only produce daughters through tychoparthenogenesis, the population sex ratio becomes more female-biased, resulting in a yet larger proportion of females not finding mates. Thus, the strength of selection fo ...
Behavioral Methods of Contraception
... effect on either sexual behavior or contraceptive use. Analysis of the “Postponing Sexual Involvement” curriculum used in 31 California counties showed no effect on sexual behavior of 7340 students participating in the program. Such programs do not delay the onset of sexual activity, but they do res ...
... effect on either sexual behavior or contraceptive use. Analysis of the “Postponing Sexual Involvement” curriculum used in 31 California counties showed no effect on sexual behavior of 7340 students participating in the program. Such programs do not delay the onset of sexual activity, but they do res ...
The Prisoner of Gender: Foucault and the Disciplining of the Female
... politic’ to talk about the politics of the body: “the human body is itself a politically inscribed entity, its physiology and morphology shaped by histories and practices of containment and control.” (Bordo 1993, p.21). Feminists identified how women have been subjugated primarily through their bod ...
... politic’ to talk about the politics of the body: “the human body is itself a politically inscribed entity, its physiology and morphology shaped by histories and practices of containment and control.” (Bordo 1993, p.21). Feminists identified how women have been subjugated primarily through their bod ...
RUNAWAY SEXUAL SELECTION LEADS TO GOOD GENES
... Mate choice and sexual displays are widespread in nature, but their evolutionary benefits remain controversial. Theory predicts these traits can be favored by runaway sexual selection, in which preference and display reinforce one another due to genetic correlation; or by good genes benefits, in whi ...
... Mate choice and sexual displays are widespread in nature, but their evolutionary benefits remain controversial. Theory predicts these traits can be favored by runaway sexual selection, in which preference and display reinforce one another due to genetic correlation; or by good genes benefits, in whi ...
sexual vs. asexual reproduction in a stick insect
... between sexual versus asexual reproduction in phasmids (Lamb & Willey 1979), if and how M. dentricus and B. extradentatum are representative o f this diverse groups remains a mystery. Interestingly, there were generally no differences in egg weight; regardless of how many eggs each female laid, thos ...
... between sexual versus asexual reproduction in phasmids (Lamb & Willey 1979), if and how M. dentricus and B. extradentatum are representative o f this diverse groups remains a mystery. Interestingly, there were generally no differences in egg weight; regardless of how many eggs each female laid, thos ...
Reproductive
... Provides a transport medium and nutrients (fructose), protects and activates sperm, and facilitates their movement Prostaglandins in semen: Decrease the viscosity of mucus in the cervix Stimulate reverse peristalsis in the uterus, facilitates movement through female reproductive tract Suppress immun ...
... Provides a transport medium and nutrients (fructose), protects and activates sperm, and facilitates their movement Prostaglandins in semen: Decrease the viscosity of mucus in the cervix Stimulate reverse peristalsis in the uterus, facilitates movement through female reproductive tract Suppress immun ...
Sex - Interstitial Cystitis Association
... percent of people with IC have difficulties with sex. For many, IC has prevented them from having any sexual intimacy. It doesn’t have to be that way. There are many ways to remain sexually active or resume your sex life, and there are treatments that can help. Most IC patients can reclaim physical ...
... percent of people with IC have difficulties with sex. For many, IC has prevented them from having any sexual intimacy. It doesn’t have to be that way. There are many ways to remain sexually active or resume your sex life, and there are treatments that can help. Most IC patients can reclaim physical ...
Dragonfl ies and Damselfl ies
... Interspecific interactions have several evolutionary consequences: for example, two species may compete, hybridize, or behave aggressively towards each other, or there may be predator–prey interactions. One consequence of these interactions is the evolution of premating reproductive isolation betwee ...
... Interspecific interactions have several evolutionary consequences: for example, two species may compete, hybridize, or behave aggressively towards each other, or there may be predator–prey interactions. One consequence of these interactions is the evolution of premating reproductive isolation betwee ...
Male Infertility and Sexual Health in Early Modern England
... focused on the failures of the female body, male infertility was not absent. The evidence presented here will give a more rounded picture of male infertility at this time and demonstrate that barrenness was not automatically blamed on women. Male infertility appeared in a wider range of medical sett ...
... focused on the failures of the female body, male infertility was not absent. The evidence presented here will give a more rounded picture of male infertility at this time and demonstrate that barrenness was not automatically blamed on women. Male infertility appeared in a wider range of medical sett ...
Course
... used by Louis Jules Duboscq in 1854 when he photographed his model in stereo, the better (one presumes), to appreciate her ...
... used by Louis Jules Duboscq in 1854 when he photographed his model in stereo, the better (one presumes), to appreciate her ...
- Wiley Online Library
... individuals, and the demography of the population is determined by their population averages. These population averages are necessarily density dependent as the summed fertility of females must equal the summed fertility of males (Caswell, 1989, chp. 10). Density dependent population regulation does ...
... individuals, and the demography of the population is determined by their population averages. These population averages are necessarily density dependent as the summed fertility of females must equal the summed fertility of males (Caswell, 1989, chp. 10). Density dependent population regulation does ...
Male genital size - Craig Layman Lab
... of natural selection are probably very weak.’’ Yet, in some taxa, particularly those where male genitalia cannot be retracted or hidden, costs of male genitalia might play a major role in shaping genital morphology through natural selection. Because many animal traits are believed to reflect an evol ...
... of natural selection are probably very weak.’’ Yet, in some taxa, particularly those where male genitalia cannot be retracted or hidden, costs of male genitalia might play a major role in shaping genital morphology through natural selection. Because many animal traits are believed to reflect an evol ...
(2015). Human Mate Choice, Evolution of. In
... When asked how much they are currently seeking a long-term mate, men do not differ from women in their desire to find a long-term mate (Buss and Schmitt, 1993; but see Schmitt et al., 2001b for sex difference). Men place a greater emphasis on faithfulness and chastity in a long-term mate than in a sh ...
... When asked how much they are currently seeking a long-term mate, men do not differ from women in their desire to find a long-term mate (Buss and Schmitt, 1993; but see Schmitt et al., 2001b for sex difference). Men place a greater emphasis on faithfulness and chastity in a long-term mate than in a sh ...
Click here for handout
... faces report more attraction to other men during ovulation. Women with masculine-looking partners said their eyes wander less, perhaps because the traits women tend to find sexy when they're fertile are already present in their partners. Journal of Evolution and Human Behavior, Nov, 2010 ...
... faces report more attraction to other men during ovulation. Women with masculine-looking partners said their eyes wander less, perhaps because the traits women tend to find sexy when they're fertile are already present in their partners. Journal of Evolution and Human Behavior, Nov, 2010 ...
Evolution of sex differences in lifespan and aging
... nuclear genes that may affect the expression of mitochondrial genes definitely are. Therefore, it is possible that males will evolve ways to counteract the negative consequences of the mitochondrial mutation load, as has been recently suggested for mitochondrial effects on male fertility [52]. For e ...
... nuclear genes that may affect the expression of mitochondrial genes definitely are. Therefore, it is possible that males will evolve ways to counteract the negative consequences of the mitochondrial mutation load, as has been recently suggested for mitochondrial effects on male fertility [52]. For e ...
parasites as a cost of reproduction
... oocysts), which builds on previous studies of lizards demonstrating that gonadectomy decreases ectoparasite loads in male striped plateau lizards (Cox & John-Alder, 2007) and female brown anoles (Cox et al., 2010). The fact that, in the present study, this treatment effect was seen for some endopara ...
... oocysts), which builds on previous studies of lizards demonstrating that gonadectomy decreases ectoparasite loads in male striped plateau lizards (Cox & John-Alder, 2007) and female brown anoles (Cox et al., 2010). The fact that, in the present study, this treatment effect was seen for some endopara ...
Maternal sexual interactions affect offspring survival and ageing
... of evidence, which contends that sexual selection can routinely favour the evolution of male traits that negatively impact on female life histories (Arnqvist & Rowe, 2005), including components of ageing (Promislow, 2003; Bonduriansky et al., 2008). Of the many traits involved in sexual interactions ...
... of evidence, which contends that sexual selection can routinely favour the evolution of male traits that negatively impact on female life histories (Arnqvist & Rowe, 2005), including components of ageing (Promislow, 2003; Bonduriansky et al., 2008). Of the many traits involved in sexual interactions ...
Adaptations to sexual selection and sexual conflict
... Gavrilets 2000; Gavrilets et al. 2001). A distinctive prediction of sexual conflict is that reproductive isolation can evolve more quickly under large population sizes (Gavrilets 2000), in contrast to classical predictions (Lande 1981). There is not yet a consistent pattern of results, with some stu ...
... Gavrilets 2000; Gavrilets et al. 2001). A distinctive prediction of sexual conflict is that reproductive isolation can evolve more quickly under large population sizes (Gavrilets 2000), in contrast to classical predictions (Lande 1981). There is not yet a consistent pattern of results, with some stu ...
Evolutionary Perspectives on Hermaphroditism in Fishes
... switch from one sex to the other [Shapiro, 1987]. For example, removal of a dominant male from a social group of protogynous fish, or removal of a female from a protandric group, may induce one or more remaining individuals to change sex. Empirically, fish typically change sex when they reach about ...
... switch from one sex to the other [Shapiro, 1987]. For example, removal of a dominant male from a social group of protogynous fish, or removal of a female from a protandric group, may induce one or more remaining individuals to change sex. Empirically, fish typically change sex when they reach about ...
Mortality Patterns and the Cost of Reproduction in a
... surgically in snakes using isoflurane anesthesia (Weatherhead and Blouin-Demers, 2004). Transmitters represented, at most, 4% of the snake’s mass. Snakes were kept overnight in the laboratory and then released at their point of capture. Following release, we located snakes using hand-held receivers ...
... surgically in snakes using isoflurane anesthesia (Weatherhead and Blouin-Demers, 2004). Transmitters represented, at most, 4% of the snake’s mass. Snakes were kept overnight in the laboratory and then released at their point of capture. Following release, we located snakes using hand-held receivers ...
correlated evolution of male and female morphologies in
... (Rowe 1994; Watson et al. 1998) and can be intense, involving a series of behavioral elements aimed at breaking both the males’ anterior and posterior grip (Lauer 1996; Lauer et al. 1996; Weigensberg and Fairbairn 1996; Arnqvist 1997). Water striders are sexually dimorphic in abdominal morphology (A ...
... (Rowe 1994; Watson et al. 1998) and can be intense, involving a series of behavioral elements aimed at breaking both the males’ anterior and posterior grip (Lauer 1996; Lauer et al. 1996; Weigensberg and Fairbairn 1996; Arnqvist 1997). Water striders are sexually dimorphic in abdominal morphology (A ...
Sensory exploitation and sexual conflict
... variation among males in the direct effects they have on female fitness. I will refer to this here as a Darwinian origin. This is a less problematic hypothesis than that suggested by Fisher (1930), since it does not rely on standing genetic variation in the breeding value for fitness among males. Fo ...
... variation among males in the direct effects they have on female fitness. I will refer to this here as a Darwinian origin. This is a less problematic hypothesis than that suggested by Fisher (1930), since it does not rely on standing genetic variation in the breeding value for fitness among males. Fo ...
Polyandry and alternative mating tactics
... influenced by the environment, including aspects of the mating event or competitor. The probabilistic underpinnings of the mixed strategy met with criticism in their application to living organisms, which were thought to be incapable of performing the required randomization process [9,10]. Gross [1] ...
... influenced by the environment, including aspects of the mating event or competitor. The probabilistic underpinnings of the mixed strategy met with criticism in their application to living organisms, which were thought to be incapable of performing the required randomization process [9,10]. Gross [1] ...
perkembangan organ reproduksi wanita dari janin sampai lahir
... the development of the primary of gonadal sex, while sex differentiation encompasses the events subsequent to gonadal organogenesis The processes are regulated by at least 70 different that are located on the sex chromosomes and autosomes and that act through a variety of mechanisms including organi ...
... the development of the primary of gonadal sex, while sex differentiation encompasses the events subsequent to gonadal organogenesis The processes are regulated by at least 70 different that are located on the sex chromosomes and autosomes and that act through a variety of mechanisms including organi ...
Coevolution of male courtship and sexual conflict
... to the next behavioral state are influenced by the current state but not by previous states. We then take the reciprocal of the mean number of transitions. We refer to this statistic as the display-tothrust rate, or DT rate. The DT rate measures the speed with which males pass from the display to a ...
... to the next behavioral state are influenced by the current state but not by previous states. We then take the reciprocal of the mean number of transitions. We refer to this statistic as the display-tothrust rate, or DT rate. The DT rate measures the speed with which males pass from the display to a ...