1. Assortative mating— a. affects genotype frequencies expected
... exacerbated by small population size. Founder effects are essentially the same process, but occur when new populations are found by just a small number of individuals from an originally large population. Challenge Questions 1. In Trinidadian guppies a combination of elegant laboratory and field expe ...
... exacerbated by small population size. Founder effects are essentially the same process, but occur when new populations are found by just a small number of individuals from an originally large population. Challenge Questions 1. In Trinidadian guppies a combination of elegant laboratory and field expe ...
Solutions - International Junior Science Olympiad
... Directional selection (I): a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction. The genetic variance of the population shifts toward a new phenotype when exposed to environmental changes. In the case of such selectio ...
... Directional selection (I): a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction. The genetic variance of the population shifts toward a new phenotype when exposed to environmental changes. In the case of such selectio ...
The making of the Fittest: Natural Selection and Adaptation
... Some traits are more advantageous (or deleterious) in certain environments than others. As a result, organisms with traits (and therefore the mutations that result in those traits) that make them better suited to a particular environment are more likely to have offspring and pass on their genes. Ove ...
... Some traits are more advantageous (or deleterious) in certain environments than others. As a result, organisms with traits (and therefore the mutations that result in those traits) that make them better suited to a particular environment are more likely to have offspring and pass on their genes. Ove ...
Genetic Algorithms and Neural Networks: A Comparison Based on
... solutions. The DNA of the biological genotype is mimicked by a bit string. Each bit string is seeded randomly for the starting phase and then goes through various (and also varying) procedures of mutation, mating after different rules, crossover, sometimes also inversion and other “changing devices” ...
... solutions. The DNA of the biological genotype is mimicked by a bit string. Each bit string is seeded randomly for the starting phase and then goes through various (and also varying) procedures of mutation, mating after different rules, crossover, sometimes also inversion and other “changing devices” ...
Natural Selection
... ▪ We can assume the locus that causes phenylketonuria (PKU) is in Hardy-Weinberg equilibrium given that 1. The PKU gene mutation rate is low 2. Mate selection is random with respect to whether or not an individual is a carrier for the PKU allele 3. Natural selection can only act on rare homozygous i ...
... ▪ We can assume the locus that causes phenylketonuria (PKU) is in Hardy-Weinberg equilibrium given that 1. The PKU gene mutation rate is low 2. Mate selection is random with respect to whether or not an individual is a carrier for the PKU allele 3. Natural selection can only act on rare homozygous i ...
evolutionary capacitance may be favored by natural
... Evolutionary capacitors phenotypically reveal a stock of cryptic genetic variation in a reversible fashion. The sudden and reversible revelation of a range of variation is fundamentally different from the gradual introduction of variation by mutation. Here I study the invasion dynamics of modifiers ...
... Evolutionary capacitors phenotypically reveal a stock of cryptic genetic variation in a reversible fashion. The sudden and reversible revelation of a range of variation is fundamentally different from the gradual introduction of variation by mutation. Here I study the invasion dynamics of modifiers ...
Genome-Wide Analysis of Natural Selection on
... studied natural selection on putative miRNA target sites and found evidence for purifying selection acting on conserved miRNA target sites in the 39 UTR, and slightly weaker but detectable purifying selection acting on non-conserved miRNA target sites[12]. Here we describe the first genome-scale stu ...
... studied natural selection on putative miRNA target sites and found evidence for purifying selection acting on conserved miRNA target sites in the 39 UTR, and slightly weaker but detectable purifying selection acting on non-conserved miRNA target sites[12]. Here we describe the first genome-scale stu ...
Genetic diversity in natural populations: a - Université Paris-Sud
... In plant–pathogen systems there have been many studies on the diversity of genes involved in resistance to pathogens and associated phenotypic variation in both cultivated and natural species, and great variation can be found at every scale. In plant–pathogen interactions there has been much emphasi ...
... In plant–pathogen systems there have been many studies on the diversity of genes involved in resistance to pathogens and associated phenotypic variation in both cultivated and natural species, and great variation can be found at every scale. In plant–pathogen interactions there has been much emphasi ...
POPULATION GENETICS LECTURE NOTES
... Coefficient of selection The speed with which allele or genotype frequency changes, is driven by the relative fitness for each allele or genotype. Fitness (w11, w12 and w22) is a relative value, usually measured in comparison with the most-fit allele/genotype in the population. Selection coefficien ...
... Coefficient of selection The speed with which allele or genotype frequency changes, is driven by the relative fitness for each allele or genotype. Fitness (w11, w12 and w22) is a relative value, usually measured in comparison with the most-fit allele/genotype in the population. Selection coefficien ...
Genetic Algorithms - Northwestern University
... • Only mutation can introduce new information (alleles) • Crossover does not change the allele frequencies of the population (thought experiment: 50% 0’s on first bit in the population, ?% after performing n crossovers) • To hit the optimum you often need a ‘lucky’ mutation ...
... • Only mutation can introduce new information (alleles) • Crossover does not change the allele frequencies of the population (thought experiment: 50% 0’s on first bit in the population, ?% after performing n crossovers) • To hit the optimum you often need a ‘lucky’ mutation ...
1 Lecture 6 Migration, Genetic Drift and Nonrandom Mating I
... c. The result of constant introductions of alleles from the mainland is that this tends to homogenize the allele frequencies on the island. d. If natural selection did not oppose the effects of immigration, then the allele frequency on the island would come to resemble that on the mainland. III. Gen ...
... c. The result of constant introductions of alleles from the mainland is that this tends to homogenize the allele frequencies on the island. d. If natural selection did not oppose the effects of immigration, then the allele frequency on the island would come to resemble that on the mainland. III. Gen ...
Course Focus Matt Lavin - Evolution
... Montana harbors two kinds of ponderosa pine, the westand east-slope forms. West-slope ponderosa pine, Pinus ponderosa subspecies ponderosa, is the im portant timber tree that occurs west of the continental divide (Figure 1). East-slope ponderosa pine, Pinus ponderosa subspecies scopulorum, often has ...
... Montana harbors two kinds of ponderosa pine, the westand east-slope forms. West-slope ponderosa pine, Pinus ponderosa subspecies ponderosa, is the im portant timber tree that occurs west of the continental divide (Figure 1). East-slope ponderosa pine, Pinus ponderosa subspecies scopulorum, often has ...
Slide 1
... Also, their eggs don't stick to the leaf; they drop off into litter. This may be adaptive, as winds blow leaves a long way from original plant at high elevations. The host plant is a perennial, so dropping into the leaf litter keeps it close to host plant. Other species, even if they used the plant, ...
... Also, their eggs don't stick to the leaf; they drop off into litter. This may be adaptive, as winds blow leaves a long way from original plant at high elevations. The host plant is a perennial, so dropping into the leaf litter keeps it close to host plant. Other species, even if they used the plant, ...
C. papyracea exercise - Wesleyan College Faculty
... Evolution is a difficult process to study directly because in most (but not all!) cases evolution proceeds slowly over the course of millions of years. Both laboratory and field studies have demonstrated the importance of a variety of evolutionary processes. These include mutation of individual gene ...
... Evolution is a difficult process to study directly because in most (but not all!) cases evolution proceeds slowly over the course of millions of years. Both laboratory and field studies have demonstrated the importance of a variety of evolutionary processes. These include mutation of individual gene ...
Establishment of new mutations under divergence and genome
... example, if assortative mating is based on habitat preference rather than differentially choosing mates in a common mating pool [34,35], or if the same allele causes assortative mating in both populations, the selection – recombination antagonism can be alleviated [28]. Moreover, if selection is str ...
... example, if assortative mating is based on habitat preference rather than differentially choosing mates in a common mating pool [34,35], or if the same allele causes assortative mating in both populations, the selection – recombination antagonism can be alleviated [28]. Moreover, if selection is str ...
Genetic consequences of directional selection in
... natural selection can be studied, random processes have to be well understood. At the level of an individual neutral locus genetic drift results in random fluctuations of allele frequencies in each generation (binomial variance of allele frequency change/generation σp² = p(1-p)/2N, where p is a fre ...
... natural selection can be studied, random processes have to be well understood. At the level of an individual neutral locus genetic drift results in random fluctuations of allele frequencies in each generation (binomial variance of allele frequency change/generation σp² = p(1-p)/2N, where p is a fre ...
Measuring and comparing evolvability and constraint
... Leamy, 2001; Magwene, 2001; Blows & Higgie, 2003; Hansen et al., 2003a; Blows et al., 2004; Blows, 2007; Cheverud & Marroig, 2007; Mitteroecker & Bookstein, 2007; Kirkpatrick, 2008). Some of these measures have an interpretation that connects them to evolutionary theory, such as Schluter’s (1996) ge ...
... Leamy, 2001; Magwene, 2001; Blows & Higgie, 2003; Hansen et al., 2003a; Blows et al., 2004; Blows, 2007; Cheverud & Marroig, 2007; Mitteroecker & Bookstein, 2007; Kirkpatrick, 2008). Some of these measures have an interpretation that connects them to evolutionary theory, such as Schluter’s (1996) ge ...
Optimizing selection for quantitative traits with information on an
... marker information as the reason for the reduced polygenic response with marker-assisted selection. This does not, however, explain the results for selection on a major gene with known effect. In the present study, the relationship between frequency of the major gene and genetic variance contributed ...
... marker information as the reason for the reduced polygenic response with marker-assisted selection. This does not, however, explain the results for selection on a major gene with known effect. In the present study, the relationship between frequency of the major gene and genetic variance contributed ...
Modeling Disease Evolution with Multilevel Selection: HIV as a
... To understand all the consequences of pathogen withinhost evolution, it is necessary to consider the variety of ways pathogens can interact not only with host immune systems, but also with each other. Although pathogens are typically considered as competing entities where individual-level selection ...
... To understand all the consequences of pathogen withinhost evolution, it is necessary to consider the variety of ways pathogens can interact not only with host immune systems, but also with each other. Although pathogens are typically considered as competing entities where individual-level selection ...
The making of the Fittest: Natural Selection and Adaptation
... • You may want to show the film more than once so students can take notes. Encourage them to write down questions they have about the film’s content. • Students should understand that individuals do not evolve but that populations evolve and that variations may be favorable, neutral, or negative. Va ...
... • You may want to show the film more than once so students can take notes. Encourage them to write down questions they have about the film’s content. • Students should understand that individuals do not evolve but that populations evolve and that variations may be favorable, neutral, or negative. Va ...
The Making of the Fittest: Natural Selection and Adaptation
... You may want to show the film more than once so students can take notes. Encourage them to write down questions they have about the film’s content. Students should understand that individuals do not evolve but that populations evolve and that variations may be favorable, neutral, or negative. Variat ...
... You may want to show the film more than once so students can take notes. Encourage them to write down questions they have about the film’s content. Students should understand that individuals do not evolve but that populations evolve and that variations may be favorable, neutral, or negative. Variat ...
The Making of the Fittest: Natural Selection and Adaptation
... • You may want to show the film more than once so students can take notes. Encourage them to write down questions they have about the film’s content. • Students should understand that individuals do not evolve but that populations evolve and that variations may be favorable, neutral, or negative. Va ...
... • You may want to show the film more than once so students can take notes. Encourage them to write down questions they have about the film’s content. • Students should understand that individuals do not evolve but that populations evolve and that variations may be favorable, neutral, or negative. Va ...
Full Text - Molecular Biology and Evolution
... with 1 reversion and 2 with 2 reversions (table 1). Although these 9 reversion trajectories (figure 1) are a small fraction of the ;18 billion possible reversion trajectories, they increase by 50% the number of accessible trajectories (table 1). Under a truncated selection scheme—the equal probabili ...
... with 1 reversion and 2 with 2 reversions (table 1). Although these 9 reversion trajectories (figure 1) are a small fraction of the ;18 billion possible reversion trajectories, they increase by 50% the number of accessible trajectories (table 1). Under a truncated selection scheme—the equal probabili ...
Chapter 26 Lecture Notes: Population Genetics I. Introduction A
... 1. Variation: Among individuals in a population there is phenotypic and genotypic variation 2. Heredity: Offspring are more similar to their parents than to unrelated individuals 3. Selection: Individuals having some phenotypes are more successful at surviving and reproducing than others B. Populati ...
... 1. Variation: Among individuals in a population there is phenotypic and genotypic variation 2. Heredity: Offspring are more similar to their parents than to unrelated individuals 3. Selection: Individuals having some phenotypes are more successful at surviving and reproducing than others B. Populati ...
Group selection
Group selection is a proposed mechanism of evolution in which natural selection is imagined to act at the level of the group, instead of at the more conventional level of the individual.Early authors such as V. C. Wynne-Edwards and Konrad Lorenz argued that the behavior of animals could affect their survival and reproduction as groups.From the mid 1960s, evolutionary biologists such as John Maynard Smith argued that natural selection acted primarily at the level of the individual. They argued on the basis of mathematical models that individuals would not altruistically sacrifice fitness for the sake of a group. They persuaded the majority of biologists that group selection did not occur, other than in special situations such as the haplodiploid social insects like honeybees (in the Hymenoptera), where kin selection was possible.In 1994 David Sloan Wilson and Elliott Sober argued for multi-level selection, including group selection, on the grounds that groups, like individuals, could compete. In 2010 three authors including E. O. Wilson, known for his work on ants, again revisited the arguments for group selection, provoking a strong rebuttal from a large group of evolutionary biologists. As of yet, there is no clear consensus among biologists regarding the importance of group selection.