How pathogens drive genetic diversity: MHC, mechanisms and
... Major histocompatibility complex (MHC) genes have been put forward as a model for studying how genetic diversity is maintained in wild populations. Pathogen-mediated selection (PMS) is believed to generate the extraordinary levels of MHC diversity observed. However, establishing the relative importa ...
... Major histocompatibility complex (MHC) genes have been put forward as a model for studying how genetic diversity is maintained in wild populations. Pathogen-mediated selection (PMS) is believed to generate the extraordinary levels of MHC diversity observed. However, establishing the relative importa ...
Evolution of mating types driven by purifying selection
... In this work I adopt the mating kinetics first developed in the models of Iwasa and Sasaki (1987), and Hutson and Law (1993). I assume the gamete pool of finite size, in which the influx of gametes matches their removal due to random death and zygote formation. The gamete influx rates are proportion ...
... In this work I adopt the mating kinetics first developed in the models of Iwasa and Sasaki (1987), and Hutson and Law (1993). I assume the gamete pool of finite size, in which the influx of gametes matches their removal due to random death and zygote formation. The gamete influx rates are proportion ...
Do male secondary sexual characters signal ejaculate quality? A
... trait is lower for higher quality males (Grafen, 1990; empirical evidence: Møller & de Lope, 1994; Kotiaho, 2000). This allows a higher quality male to invest more into a SSC, without the resultant mating gains immediately being negated by greater costs. It has, however, been noted that this interpr ...
... trait is lower for higher quality males (Grafen, 1990; empirical evidence: Møller & de Lope, 1994; Kotiaho, 2000). This allows a higher quality male to invest more into a SSC, without the resultant mating gains immediately being negated by greater costs. It has, however, been noted that this interpr ...
ENVIRONMENTAL STRESS AND ITS EFFECTS ON MUTATION
... genome is possible because most mutations are considered to be either neutral or only slightly deleterious in the organisms current environment (Kimura 1984, Drake 1991), and are thus not selected against. The important concept is the "current environment" of the population. If the environment chang ...
... genome is possible because most mutations are considered to be either neutral or only slightly deleterious in the organisms current environment (Kimura 1984, Drake 1991), and are thus not selected against. The important concept is the "current environment" of the population. If the environment chang ...
Introduction to Genetics
... 9. Where would your organisms live? What adaptations do they have for living in that environment? Offspring Congratulations, your organisms reproduced! Now, based on the information you gave earlier about the traits of the parents, you are going to determine what the offspring will look like. 10. U ...
... 9. Where would your organisms live? What adaptations do they have for living in that environment? Offspring Congratulations, your organisms reproduced! Now, based on the information you gave earlier about the traits of the parents, you are going to determine what the offspring will look like. 10. U ...
Mendelian Genetics— patterns of Inheritance
... Researchers in modern genetics laboratories now study how specific characteristics are passed on from parent to offspring. However, humans have studied the characteristics of plants and animals ever since the beginning of organized agriculture. Early farmers realized that selective breeding resulted ...
... Researchers in modern genetics laboratories now study how specific characteristics are passed on from parent to offspring. However, humans have studied the characteristics of plants and animals ever since the beginning of organized agriculture. Early farmers realized that selective breeding resulted ...
Selection and Adaptation of Fitness
... desired traits, and the phenotypic characteristics of these species have been widely altered. Domesticated populations are excellent models to study the mechanism of adaptive evolution. In particular, such populations could be utilized to study the direct and indirect results of concerted selection ...
... desired traits, and the phenotypic characteristics of these species have been widely altered. Domesticated populations are excellent models to study the mechanism of adaptive evolution. In particular, such populations could be utilized to study the direct and indirect results of concerted selection ...
Frequency-Dependent Selection and the Evolution
... Assortative mating that arises because individuals mate within groups (formed in time or space) is most conducive to the evolution of complete assortative mating from random mating. Assortative mating based on female preferences is more restrictive, because the resulting sexual selection can lead to ...
... Assortative mating that arises because individuals mate within groups (formed in time or space) is most conducive to the evolution of complete assortative mating from random mating. Assortative mating based on female preferences is more restrictive, because the resulting sexual selection can lead to ...
icsi sperm selection by ha binding
... ICSI SPERM SELECTION BY HA BINDING : IS IT SAFE? HA occurs normally in the female reproductive tract and in the cumulus oophorus. HA is carried with the spermatozoa into oocytes even during in-vivo conception, The removal of spermatozoa from HA may cause a few HA molecules to attach to spermato ...
... ICSI SPERM SELECTION BY HA BINDING : IS IT SAFE? HA occurs normally in the female reproductive tract and in the cumulus oophorus. HA is carried with the spermatozoa into oocytes even during in-vivo conception, The removal of spermatozoa from HA may cause a few HA molecules to attach to spermato ...
Pedigree Analysis
... families, particularly large extended families. Pedigrees are often used to determine the mode of inheritance (dominant, recessive, etc.) of genetic diseases. A sample pedigree is below. ...
... families, particularly large extended families. Pedigrees are often used to determine the mode of inheritance (dominant, recessive, etc.) of genetic diseases. A sample pedigree is below. ...
Chapter 3: Selection and Adaptation Barry Sinervo © 1997-2007
... Alternatively, male competition or intrasexual selection arises in which males compete for territory or access to females, or they compete on mating grounds where displays take place. Male-male competition can lead to intense battles for access to females where males use elaborate armaments (e.g., h ...
... Alternatively, male competition or intrasexual selection arises in which males compete for territory or access to females, or they compete on mating grounds where displays take place. Male-male competition can lead to intense battles for access to females where males use elaborate armaments (e.g., h ...
Having sex, yes, but with whom? Inferences from fungi on the
... (2004) proposed that mating types were selected for because they prevented syngamy between identical haploid clones. They showed that, if the spatial distribution of identical haploids is clumped, mating types determined at the haploid level can evolve to ensure mating between different haploid geno ...
... (2004) proposed that mating types were selected for because they prevented syngamy between identical haploid clones. They showed that, if the spatial distribution of identical haploids is clumped, mating types determined at the haploid level can evolve to ensure mating between different haploid geno ...
Having sex, yes, but with whom? Inferences from fungi
... (2004) proposed that mating types were selected for because they prevented syngamy between identical haploid clones. They showed that, if the spatial distribution of identical haploids is clumped, mating types determined at the haploid level can evolve to ensure mating between different haploid geno ...
... (2004) proposed that mating types were selected for because they prevented syngamy between identical haploid clones. They showed that, if the spatial distribution of identical haploids is clumped, mating types determined at the haploid level can evolve to ensure mating between different haploid geno ...
Population Genetics A Concise Guide - IB-USP
... Population geneticists spend most of their time doing one of two things: describing the genetic structure of populations or theorizing on the evolutionary forces acting on populations. On a good day, these two activities mesh and true insights emerge. In this chapter, wewill do all of the above. The ...
... Population geneticists spend most of their time doing one of two things: describing the genetic structure of populations or theorizing on the evolutionary forces acting on populations. On a good day, these two activities mesh and true insights emerge. In this chapter, wewill do all of the above. The ...
HS-SCI-APB-Unit 3 -- Chapter 14- Mendel and the
... with purple flowers is true-breeding if the seeds produced by self-pollination in successive generations all give rise to plants that also have purple flowers. In a typical breeding experiment, Mendel cross-pollinated two contrasting, true-breeding pea varieties-for example, purple-flowered plants a ...
... with purple flowers is true-breeding if the seeds produced by self-pollination in successive generations all give rise to plants that also have purple flowers. In a typical breeding experiment, Mendel cross-pollinated two contrasting, true-breeding pea varieties-for example, purple-flowered plants a ...
Neurospora - DiVA portal
... Neurospora genomes provide a powerful resource for genomic comparative biology, exploring the evolutionary dynamics of these species. ...
... Neurospora genomes provide a powerful resource for genomic comparative biology, exploring the evolutionary dynamics of these species. ...
1 Frequency-dependent selection and the evolution of assortative
... study focuses only on one trait locus (unlike de CARA et al. 2008), focusing on a single trait locus allows us to explore a broad array of forms of assortative mating and to consider both strong and weak selection, modifiers of strong and weak effect, and arbitrary costs. Selective forces acting in ...
... study focuses only on one trait locus (unlike de CARA et al. 2008), focusing on a single trait locus allows us to explore a broad array of forms of assortative mating and to consider both strong and weak selection, modifiers of strong and weak effect, and arbitrary costs. Selective forces acting in ...
Mende an the Gee 11I+t
... that they are available in many varieties. For example, one variety has purple flowers, while another variety has white flowers. A heritable feature that varies among individuals, such as flower color, is called a character. Each variant for a character, such as purple or white color for flowers, is ...
... that they are available in many varieties. For example, one variety has purple flowers, while another variety has white flowers. A heritable feature that varies among individuals, such as flower color, is called a character. Each variant for a character, such as purple or white color for flowers, is ...
A quantitative genetic competition model for
... I use multilocus genetics to describe assortative mating in a competition model. The intensity of competition between individuals is influenced by a quantitative character whose value is determined additively by alleles from many loci. With assortative mating based on this character, frequency- and ...
... I use multilocus genetics to describe assortative mating in a competition model. The intensity of competition between individuals is influenced by a quantitative character whose value is determined additively by alleles from many loci. With assortative mating based on this character, frequency- and ...
X-linked Recessive Traits
... X-linked Recessive Traits (Examples: Hemophilia and Colorblindness) 10) If the trait is X-linked recessive, then the X and Y chromosomes need to be indicated in the genotype. In the table below, identify the phenotypes of ALL the possible genotypes below AND assign the appropriate pedigree symbol. T ...
... X-linked Recessive Traits (Examples: Hemophilia and Colorblindness) 10) If the trait is X-linked recessive, then the X and Y chromosomes need to be indicated in the genotype. In the table below, identify the phenotypes of ALL the possible genotypes below AND assign the appropriate pedigree symbol. T ...
Introduction to Genetics
... (mom has black, offspring has white), different mouth (mom is frown, offspring is smile). 23. What traits does offspring 3 have that are the same as offspring 1? What traits are different? Same shape (square), same eyes (white). Different color (3 is purple, 1 is green), different mouth (3 is smilin ...
... (mom has black, offspring has white), different mouth (mom is frown, offspring is smile). 23. What traits does offspring 3 have that are the same as offspring 1? What traits are different? Same shape (square), same eyes (white). Different color (3 is purple, 1 is green), different mouth (3 is smilin ...
Genetic Allee effects and their interaction with ecological
... composition and growth rate of a population change over time, but we need to keep in mind that all results will be relative to the genetic composition of the source population. We focus on one important candidate mechanism for genetic Allee effects: inbreeding depression due to recessive deleterious ...
... composition and growth rate of a population change over time, but we need to keep in mind that all results will be relative to the genetic composition of the source population. We focus on one important candidate mechanism for genetic Allee effects: inbreeding depression due to recessive deleterious ...
(From the ZoOlogical Laboratory of Columbia
... That the deficient region actually does extend to the left of the vermilion locus was indicated by use of vermilion-duplication. The stock of vermilion-duplication consists of flies homozygous for the vermilion gene and at the same time homozygous for the not-vermilion gene, since these flies carry ...
... That the deficient region actually does extend to the left of the vermilion locus was indicated by use of vermilion-duplication. The stock of vermilion-duplication consists of flies homozygous for the vermilion gene and at the same time homozygous for the not-vermilion gene, since these flies carry ...
Evolutionary advantages and drawbacks of uni- versus bi
... Recognition of a compatible mate occurs by a pheromone/receptor interaction. In ascomycetes and mucoromycetes, each mating type produces one type of pheromone, activating the receptor of the other mating type, and they produce a receptor that responds to the pheromone from the other mating type (Kot ...
... Recognition of a compatible mate occurs by a pheromone/receptor interaction. In ascomycetes and mucoromycetes, each mating type produces one type of pheromone, activating the receptor of the other mating type, and they produce a receptor that responds to the pheromone from the other mating type (Kot ...
Inbreeding avoidance
Inbreeding avoidance, or the inbreeding avoidance hypothesis, is a concept in evolutionary biology that refers to the prevention of the deleterious effects of inbreeding. The inbreeding avoidance hypothesis posits that certain mechanisms develop within a species, or within a given population of a species, as a result of natural and sexual selection in order to prevent breeding among related individuals in that species or population. Although inbreeding may impose certain evolutionary costs, inbreeding avoidance, which limits the number of potential mates for a given individual, can inflict opportunity costs. Therefore, a balance exists between inbreeding and inbreeding avoidance. This balance determines whether inbreeding mechanisms develop and the specific nature of said mechanisms.Inbreeding results in inbreeding depression, which is the reduction of fitness of a given population due to inbreeding. Inbreeding depression occurs via one of two mechanisms. The first mechanism involves the appearance of disadvantageous traits via the pairing of deleterious recessive alleles in a mating pair’s progeny. When two related individuals mate, the probability of deleterious recessive alleles pairing in the resulting offspring is higher as compared to when non-related individuals mate. The second mechanism relates to the increased fitness of heterozygotes. Many studies have demonstrated that homozygous individuals are often disadvantaged with respect to heterozygous individuals. For example, a study conducted on a population of South African cheetahs demonstrated that the lack of genetic variability among individuals in the population has resulted in negative consequences for individuals, such as a greater rate of juvenile mortality and spermatozoal abnormalities. When heterozygotes possess a fitness advantage relative to a homozygote, a population with a large number of homozygotes will have a relatively reduced fitness, thus leading to inbreeding depression. Through these described mechanisms, the effects of inbreeding depression are often severe enough to cause the evolution of inbreeding avoidance mechanisms.