Navodaya Vidyalaya Samiti – Bhopal Region.
... oocyte(ovum) by the process called ovulation. *menstrual cycle- It is a cyclic process of 28/29 days by which one ovum is released. The 1st menstruation of a female begins at puberty is called a menarche. The phrases of menstruation cycle are- menstruation, follicular phase, luteal phase. Secretion ...
... oocyte(ovum) by the process called ovulation. *menstrual cycle- It is a cyclic process of 28/29 days by which one ovum is released. The 1st menstruation of a female begins at puberty is called a menarche. The phrases of menstruation cycle are- menstruation, follicular phase, luteal phase. Secretion ...
Sexual Selection in Yeast
... their current environment. So why should it want to break up this successful combinations of genes by having sex? In 1975, Williams argued that asexual organisms will produce offspring that will stay close to the parent, so will have a genome that is well suited to their environment. In addition ...
... their current environment. So why should it want to break up this successful combinations of genes by having sex? In 1975, Williams argued that asexual organisms will produce offspring that will stay close to the parent, so will have a genome that is well suited to their environment. In addition ...
Sexual reproduction
... Reproduction in animals is varied Sexual reproduction (some invertebrates, earthworms, plants and animals): sex cells, or gametes, produced by the parents unite to form a genetically unique individual. Copulation is the sexual union to facilitate the reception of sperm and to protect sperm from dry ...
... Reproduction in animals is varied Sexual reproduction (some invertebrates, earthworms, plants and animals): sex cells, or gametes, produced by the parents unite to form a genetically unique individual. Copulation is the sexual union to facilitate the reception of sperm and to protect sperm from dry ...
Sexual reproduction
... Reproduction in animals is varied Sexual reproduction (some invertebrates, earthworms, plants and animals): sex cells, or gametes, produced by the parents unite to form a genetically unique individual. Copulation is the sexual union to facilitate the reception of sperm and to protect sperm from dry ...
... Reproduction in animals is varied Sexual reproduction (some invertebrates, earthworms, plants and animals): sex cells, or gametes, produced by the parents unite to form a genetically unique individual. Copulation is the sexual union to facilitate the reception of sperm and to protect sperm from dry ...
Standard PDF - Wiley Online Library
... that outbreed; the occurrence of inbreeding depression in offspring fitness does not mean that parents’ initial fecundities will necessarily decrease with the degree to which they inbreed (e.g., Keller 1998; Kruuk et al. 2002; Firman and Simmons 2007; Schørring and Jäger 2007; Edvardsson et al. 200 ...
... that outbreed; the occurrence of inbreeding depression in offspring fitness does not mean that parents’ initial fecundities will necessarily decrease with the degree to which they inbreed (e.g., Keller 1998; Kruuk et al. 2002; Firman and Simmons 2007; Schørring and Jäger 2007; Edvardsson et al. 200 ...
On the assignment of fitness to parents and offspring: whose fitness
... Cheverud & Moore, 1994). On one hand, evolutionary genetic theorists assert that the ®tness of one individual should never be assigned to another (e.g. Cheverud & Moore, 1994). Under this theoretical genetic perspective, it is recommended that, in empirical studies, ®tness be counted from conception ...
... Cheverud & Moore, 1994). On one hand, evolutionary genetic theorists assert that the ®tness of one individual should never be assigned to another (e.g. Cheverud & Moore, 1994). Under this theoretical genetic perspective, it is recommended that, in empirical studies, ®tness be counted from conception ...
on the opportunity for sexual selection, the bateman gradient and
... If precopulatory sexual selection arises as a consequence of competition for access to mates, then the currency of sexual selection should be the number of mates or the number of offspring produced during a selection episode. For example, a selection episode could be a particular breeding season. In ...
... If precopulatory sexual selection arises as a consequence of competition for access to mates, then the currency of sexual selection should be the number of mates or the number of offspring produced during a selection episode. For example, a selection episode could be a particular breeding season. In ...
Fitness effects of thermal stress differ between outcrossing
... which their findings can be generalized. Here, we use Caenorhabditis elegans – a free-living nematode species in which hermaphrodites (capable of selfing but not cross-fertilizing each other) coexist with males (capable of fertilizing hermaphrodites) – to investigate the response of wild type as wel ...
... which their findings can be generalized. Here, we use Caenorhabditis elegans – a free-living nematode species in which hermaphrodites (capable of selfing but not cross-fertilizing each other) coexist with males (capable of fertilizing hermaphrodites) – to investigate the response of wild type as wel ...
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 ...
The love-darts of land snails: integrating physiology, morphology
... have spines on their penes that damage the female tract (Crudgington and SivaJothy, 2000; Hotzy and Arnqvist, 2009). A comparative analysis by Rönn et al. (2007) revealed that females belonging to species in which males have more elaborate penial spines had a thicker connective tissue layer in the v ...
... have spines on their penes that damage the female tract (Crudgington and SivaJothy, 2000; Hotzy and Arnqvist, 2009). A comparative analysis by Rönn et al. (2007) revealed that females belonging to species in which males have more elaborate penial spines had a thicker connective tissue layer in the v ...
Adaptive speciation when assortative mating is
... values for the parameters r, K0, rK, rc, s, and l; the number of loci determining each of the four traits; and the initial number of males and females, together with their genetic make-up. The parameters r and K0 do not have a qualitative effect on the results reported below, essentially because the ...
... values for the parameters r, K0, rK, rc, s, and l; the number of loci determining each of the four traits; and the initial number of males and females, together with their genetic make-up. The parameters r and K0 do not have a qualitative effect on the results reported below, essentially because the ...
Mammal Reproductive Strategies Driven by Offspring Mortality
... shown in figure 3C. The relative positions of the standardized points are the same irrespective of which z contour is chosen for standardization. This procedure allows analysis of trade-offs after standardization for the quantity of resource available for allocation. This conceptual framework allows ...
... shown in figure 3C. The relative positions of the standardized points are the same irrespective of which z contour is chosen for standardization. This procedure allows analysis of trade-offs after standardization for the quantity of resource available for allocation. This conceptual framework allows ...
Long-Tailed Weasel - Vermont Fish and Wildlife
... slim body, long neck and short legs. It is very agile and fast when on the move, slinking along in an up and down fashion. The tail is brown with a black tip. The long-tailed weasel's coat changes color with the seasons. It is dark brown to red in the summer with lighter underparts and dark feet. In ...
... slim body, long neck and short legs. It is very agile and fast when on the move, slinking along in an up and down fashion. The tail is brown with a black tip. The long-tailed weasel's coat changes color with the seasons. It is dark brown to red in the summer with lighter underparts and dark feet. In ...
Chapter 4
... Three major, non-exclusive selective pressures have received the majority of attention as ultimate explanations for SSD in reptiles: (1) sexual selection, which arises through variance in mating success and is usually invoked in the context of large male size conferring an advantage in male– male co ...
... Three major, non-exclusive selective pressures have received the majority of attention as ultimate explanations for SSD in reptiles: (1) sexual selection, which arises through variance in mating success and is usually invoked in the context of large male size conferring an advantage in male– male co ...
Color and Communication in Habronattus Jumping Spiders: Tests of
... exhibit diverse and brilliant coloration, they have been notably absent from such studies. In the genus Habronattus, females are drab and cryptic while males are brilliantly colored, displaying some of these colors to females during elaborate courtship dances. Here I test multiple hypotheses for the ...
... exhibit diverse and brilliant coloration, they have been notably absent from such studies. In the genus Habronattus, females are drab and cryptic while males are brilliantly colored, displaying some of these colors to females during elaborate courtship dances. Here I test multiple hypotheses for the ...
Sexual selection and temporal phenotypic variation in a damselfly
... because the male’s claspers contact the female’s thorax on a pair of plates that are of a characteristic shape (Westfall & May, 2006; McPeek et al., 2008, 2009), a male that is too large may also have difficulty in securing a sufficient grip on the female because of an improper fit between these par ...
... because the male’s claspers contact the female’s thorax on a pair of plates that are of a characteristic shape (Westfall & May, 2006; McPeek et al., 2008, 2009), a male that is too large may also have difficulty in securing a sufficient grip on the female because of an improper fit between these par ...
On the Evolution of Premating Isolation after a Founder Event
... 1984). In the Hawaiian archipelago, most species of Drosophila are endemic to a single island (Carson 1982). The evidence from geology, chromosomal inversion patterns, and prevailing winds suggests that the majority of speciation events occurred after colonization of a new island that had recently b ...
... 1984). In the Hawaiian archipelago, most species of Drosophila are endemic to a single island (Carson 1982). The evidence from geology, chromosomal inversion patterns, and prevailing winds suggests that the majority of speciation events occurred after colonization of a new island that had recently b ...
Temperature- Dependent Sex Determination (TSD): benefits and
... Nelson 1991). This however seems unlikely as a primary mechanism due to the fact that many species exhibiting TSD are long lived, and unless completely random mating occurs in a population, it is likely that close sibling mating could occur from cohorts originating in different years, especially wi ...
... Nelson 1991). This however seems unlikely as a primary mechanism due to the fact that many species exhibiting TSD are long lived, and unless completely random mating occurs in a population, it is likely that close sibling mating could occur from cohorts originating in different years, especially wi ...
Mating behavior and the evolution of sperm design
... concluded that we “currently have only a rudimentary understanding of the adaptive significance of [the awe-inspiring variation in sperm form]” and that we “know very little about sperm behavior, particularly within the female reproductive tract” (9). The reason for this lack of understanding is that ...
... concluded that we “currently have only a rudimentary understanding of the adaptive significance of [the awe-inspiring variation in sperm form]” and that we “know very little about sperm behavior, particularly within the female reproductive tract” (9). The reason for this lack of understanding is that ...
and Empirical Studies - The University of New Mexico
... The Trade-Off Between Current and Future Reproduction According to the theory of evolution by natural selection, the evolution of life is the result of a process in which variant forms compete to harvest energy from the environment and convert that energy into replicates of those forms. Those forms ...
... The Trade-Off Between Current and Future Reproduction According to the theory of evolution by natural selection, the evolution of life is the result of a process in which variant forms compete to harvest energy from the environment and convert that energy into replicates of those forms. Those forms ...
Ecology and Reproductive Characteristics of the Skink
... Wen-San Huang (2010) Ecology and reproductive characteristics of the skink Sphenomorphus incognitus on an East Asian island, with comments on variations in clutch size with reproductive modes in Sphenomorphus. Zoological Studies 49(6): 779-788. I describe the diet, and male and female reproductive c ...
... Wen-San Huang (2010) Ecology and reproductive characteristics of the skink Sphenomorphus incognitus on an East Asian island, with comments on variations in clutch size with reproductive modes in Sphenomorphus. Zoological Studies 49(6): 779-788. I describe the diet, and male and female reproductive c ...
What is the appropriate timescale for measuring
... body condition at the ®rst capture (indicating that they were not post-parturient: e.g. absence of ¯accid abdomen or extensive skin folds), and they needed to have been regularly recaptured (so that we were sure that they did not produce a litter during this period). Some of them were ®rst caught as ...
... body condition at the ®rst capture (indicating that they were not post-parturient: e.g. absence of ¯accid abdomen or extensive skin folds), and they needed to have been regularly recaptured (so that we were sure that they did not produce a litter during this period). Some of them were ®rst caught as ...
132 Florida Entomologist 80(2)
... In butterflies, several types of iridescent scales have been described. The average lepidopteran wing has rows of alternate long and short scales. The longer are cover scales, which arch over and hide the short, ground scales. In iridescent patches, the cover scales are specialized, but the ground s ...
... In butterflies, several types of iridescent scales have been described. The average lepidopteran wing has rows of alternate long and short scales. The longer are cover scales, which arch over and hide the short, ground scales. In iridescent patches, the cover scales are specialized, but the ground s ...
genetic differentiation by sexual conflict
... and Hosken 2003) directly show that sexual conflict causes rapid coevolution in reproductive traits. Molecular studies also demonstrate rapid evolution in many genes that mediate sexual reproduction, such as those involved in gamete recognition (reviewed in Swanson and Vacquier 2002). At least some ...
... and Hosken 2003) directly show that sexual conflict causes rapid coevolution in reproductive traits. Molecular studies also demonstrate rapid evolution in many genes that mediate sexual reproduction, such as those involved in gamete recognition (reviewed in Swanson and Vacquier 2002). At least some ...