Why do sperm carry RNA? Relatedness, conflict
... the size of nuptial gifts. Nuptial gifts can be thought of as a form of male reproductive investment (or mating effort) provided to females in return for matings [44,45]. They are found across a large number of taxa, and males have been found to tailor these gifts in relation to the likelihood of si ...
... the size of nuptial gifts. Nuptial gifts can be thought of as a form of male reproductive investment (or mating effort) provided to females in return for matings [44,45]. They are found across a large number of taxa, and males have been found to tailor these gifts in relation to the likelihood of si ...
Lifetime Reproductive Effort
... Vitt 1986). Because such interannual variation creates inaccuracy in measurements of average clutch size and number, as well as survival, LRE calculations for these taxa are inherently imprecise. Field measures of clutch number in tropical species of gecko must also come with a high degree of error. ...
... Vitt 1986). Because such interannual variation creates inaccuracy in measurements of average clutch size and number, as well as survival, LRE calculations for these taxa are inherently imprecise. Field measures of clutch number in tropical species of gecko must also come with a high degree of error. ...
Color and Communication in Habronattus Jumping Spiders: Tests of
... Differences between males and females can evolve through a variety of mechanisms, including sexual and ecological selection. Because coloration is evolutionarily labile, sexually dichromatic species are good models for understanding the evolution of sex differences. While many jumping spiders exhibi ...
... Differences between males and females can evolve through a variety of mechanisms, including sexual and ecological selection. Because coloration is evolutionarily labile, sexually dichromatic species are good models for understanding the evolution of sex differences. While many jumping spiders exhibi ...
Lesson 2 | Asexual Reproduction
... Some organisms can produce offspring without meiosis or fertilization. You can observe this process when you add sugar and warm water to dried yeast. ...
... Some organisms can produce offspring without meiosis or fertilization. You can observe this process when you add sugar and warm water to dried yeast. ...
Reproduction - Male
... Having common membranes and blood supply results (>90% of the time) in Freemartin condition of heifer (Freemartinism). ...
... Having common membranes and blood supply results (>90% of the time) in Freemartin condition of heifer (Freemartinism). ...
How to read “heritability” in the recipe approach to - Philsci
... offspring as a necessary condition. But what does it mean to have heredity between parents and offspring? In its most general sense, it simply means that there is the transmission of traits between parent and offspring associated with a parent-offspring resemblance (Godfrey-Smith [2009], 24). One pr ...
... offspring as a necessary condition. But what does it mean to have heredity between parents and offspring? In its most general sense, it simply means that there is the transmission of traits between parent and offspring associated with a parent-offspring resemblance (Godfrey-Smith [2009], 24). One pr ...
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 ...
Life Science: Session 4
... healthy genes remain active in a given population. Sexual reproduction takes place only after the male and female mate. The males produce sperms and females eggs. The gonads, that is, eggs and sperms are haploid cells. When the sperm fertilizes the egg, it gives rise to a diploid cell containing ge ...
... healthy genes remain active in a given population. Sexual reproduction takes place only after the male and female mate. The males produce sperms and females eggs. The gonads, that is, eggs and sperms are haploid cells. When the sperm fertilizes the egg, it gives rise to a diploid cell containing ge ...
Mate choice inside an egg cell.
... signals and female preferences for those signals (Andersson 1994). Although Darwin (1871) proposed his ideas to account for elaborate pre-copulatory sexual displays and preferences, his ideas have since been expanded to include forms of post-copulatory choice, such as sperm competition (Parker 1970 ...
... signals and female preferences for those signals (Andersson 1994). Although Darwin (1871) proposed his ideas to account for elaborate pre-copulatory sexual displays and preferences, his ideas have since been expanded to include forms of post-copulatory choice, such as sperm competition (Parker 1970 ...
Reproductive versus ecological advantages to larger body size in
... survival) and reproductive output (reproductive frequency, litter size, offspring size, offspring viability) in free-ranging female aspic vipers, Vipera aspis. The less-than-annual reproductive frequency of these animals allows us to make a direct comparison between females in years during which the ...
... survival) and reproductive output (reproductive frequency, litter size, offspring size, offspring viability) in free-ranging female aspic vipers, Vipera aspis. The less-than-annual reproductive frequency of these animals allows us to make a direct comparison between females in years during which the ...
The mating system of the brown bear Ursus arctos
... An animal species’ mating system refers to the general behavioural strategies employed in obtaining mates, and includes features such as number of mates, manner of mate acquisition, characteristics of association and parental care (Emlen & Oring 1977). Mating systems and strategies are driven by the ...
... An animal species’ mating system refers to the general behavioural strategies employed in obtaining mates, and includes features such as number of mates, manner of mate acquisition, characteristics of association and parental care (Emlen & Oring 1977). Mating systems and strategies are driven by the ...
Asexual Reproduction - Advanced
... Asexual reproduction can be very rapid. This is an advantage for many organisms. It allows these organisms to crowd out other organisms that reproduce more slowly. Bacteria, for example, may divide several times per hour. Under ideal conditions, 100 bacteria can divide to produce millions of bacteri ...
... Asexual reproduction can be very rapid. This is an advantage for many organisms. It allows these organisms to crowd out other organisms that reproduce more slowly. Bacteria, for example, may divide several times per hour. Under ideal conditions, 100 bacteria can divide to produce millions of bacteri ...
Fitness effects of thermal stress differ between outcrossing
... evolution’s mysteries. Compared to uniparental reproduction (asexuality or self-fertilization), it incurs considerable costs, particularly when associated with the production of males which facilitate outcrossing but do not themselves bear offspring, while requiring energy resources that could have ...
... evolution’s mysteries. Compared to uniparental reproduction (asexuality or self-fertilization), it incurs considerable costs, particularly when associated with the production of males which facilitate outcrossing but do not themselves bear offspring, while requiring energy resources that could have ...
reproduction - Teaching Biology Project
... Dormancy prevents seeds from hatching in wrong season when seedlings would be exposed to unfavourable conditions. Allows seeds to survive unfavourable conditions. Allows for seed dispersal agents to act. Lorraine Kuun, July 2011 ...
... Dormancy prevents seeds from hatching in wrong season when seedlings would be exposed to unfavourable conditions. Allows seeds to survive unfavourable conditions. Allows for seed dispersal agents to act. Lorraine Kuun, July 2011 ...
REPRODUCTION - Teaching Biology Project
... Dormancy prevents seeds from hatching in wrong season when seedlings would be exposed to unfavourable conditions. Allows seeds to survive unfavourable conditions. Allows for seed dispersal agents to act. Lorraine Kuun, July 2011 ...
... Dormancy prevents seeds from hatching in wrong season when seedlings would be exposed to unfavourable conditions. Allows seeds to survive unfavourable conditions. Allows for seed dispersal agents to act. Lorraine Kuun, July 2011 ...
Full text in pdf format
... the sex ratio towards females and decreasing mean male body size (Smith & Jamieson 1991, Ginsberg & Milner-Gulland 1994, Sato et al. 2005). Females in populations subjected to such biased harvesting may receive reduced sperm supplies that limit their reproductive success, which can result in a decre ...
... the sex ratio towards females and decreasing mean male body size (Smith & Jamieson 1991, Ginsberg & Milner-Gulland 1994, Sato et al. 2005). Females in populations subjected to such biased harvesting may receive reduced sperm supplies that limit their reproductive success, which can result in a decre ...
Reproduction in Organisms
... Q. 2. Which is a better mode of reproduction: sexual or asexual? Why? Ans. Sexual reproduction is considered a better mode as it gives rise to genetic variation. (i) This genetic variation may confer some survival advantages on the offspring, under stressful environmental conditions. (ii) It ...
... Q. 2. Which is a better mode of reproduction: sexual or asexual? Why? Ans. Sexual reproduction is considered a better mode as it gives rise to genetic variation. (i) This genetic variation may confer some survival advantages on the offspring, under stressful environmental conditions. (ii) It ...
Lesson 2 | Asexual Reproduction
... scientists can use a meristem to make a copy of a plant with desirable traits. ...
... scientists can use a meristem to make a copy of a plant with desirable traits. ...
LIFE-HISTORY EVOLUTION IN REPTILES
... own metabolic processes, reptiles are ectotherms. By exploiting ambient thermal heterogeneity to control its internal temperature, a reptile may be able to achieve a body temperature as high as that of a sympatric endotherm at much less energy cost—for example, simply by basking in a patch of sunlig ...
... own metabolic processes, reptiles are ectotherms. By exploiting ambient thermal heterogeneity to control its internal temperature, a reptile may be able to achieve a body temperature as high as that of a sympatric endotherm at much less energy cost—for example, simply by basking in a patch of sunlig ...
Assortative mating among animals of captive and wild origin
... consideration. After just three generations in captivity, we found that captive–captive and wild–wild pairs accounted for 83% of all offspring produced, inferring strong assortative mating between animals in relation to their origin. Multiple causes for the observed assortative mating are possible [ ...
... consideration. After just three generations in captivity, we found that captive–captive and wild–wild pairs accounted for 83% of all offspring produced, inferring strong assortative mating between animals in relation to their origin. Multiple causes for the observed assortative mating are possible [ ...
Unifying Within- and Between-Generation Bet
... abstract: In the 1970s, John Gillespie introduced two principles in which evolution selects for genotypes with lower variation in offspring numbers. First, if the variation in offspring number primarily occurs within generations, the strength of this selective force is inversely proportional to popu ...
... abstract: In the 1970s, John Gillespie introduced two principles in which evolution selects for genotypes with lower variation in offspring numbers. First, if the variation in offspring number primarily occurs within generations, the strength of this selective force is inversely proportional to popu ...
Parental Effects in Plantago Lanceolata LI: A Growth
... expression of fitness traits in offspring (see reviews of plants, Rowe 1964; Schaal 1984; Roach and Wulff 1987; Lacey 1991; insects, Mousseau and Dingle 1991; fishes, Reznick 1991; mammals, Cowley 1991; amphibians, Kaplan 1991; reptiles, Sinervo 1991). In spite of their pervasiveness, many aspects o ...
... expression of fitness traits in offspring (see reviews of plants, Rowe 1964; Schaal 1984; Roach and Wulff 1987; Lacey 1991; insects, Mousseau and Dingle 1991; fishes, Reznick 1991; mammals, Cowley 1991; amphibians, Kaplan 1991; reptiles, Sinervo 1991). In spite of their pervasiveness, many aspects o ...
Document
... Egg begins development without sperm Narrows the diversity available for adaptation to new conditions - not clones of female (haploid cells replicate) Examples: fleas, bees, aphids, some fish and lizards ...
... Egg begins development without sperm Narrows the diversity available for adaptation to new conditions - not clones of female (haploid cells replicate) Examples: fleas, bees, aphids, some fish and lizards ...
Parental investment
Parental investment (PI), in evolutionary biology and evolutionary psychology, is any parental expenditure (time, energy etc.) that benefits one offspring at a cost to parents' ability to invest in other components of fitness, and is thus a form of sexual selection. Components of fitness include the wellbeing of existing offspring, parents' future sexual reproduction, and inclusive fitness through aid to kin. Parental investment may be performed by both the male and female (biparental care), the mother alone (exclusive maternal care) or the father alone (exclusive paternal care).Initially introduced in 1930 by the English biologist and statistician Ronald Fisher, parental care is found in a broad range of taxonomic groups, including both ectothermic (invertebrates, fish, amphibians and reptiles), and endothermic (birds and mammals) species. Care can be provided at any stage of the offspring's life: pre-natal care including behaviours such as egg guarding, preparation of nest, brood carrying, incubation, and placental nourishment in mammals; and post-natal care including food provisioning and protection of offspring.