This document discusses population genetics and key concepts in evolutionary biology. It covers Mendelian genetics, the Hardy-Weinberg principle of equilibrium, mechanisms of evolution like genetic variation, natural selection and genetic drift. It also discusses applications of population genetics like estimating allele frequencies, measuring genetic variation, and using DNA polymorphisms in forensics.
B.sc. agri i pog unit 4 population geneticsRai University
This document provides an overview of population genetics and principles of evolution. It discusses how genetic variation is maintained in populations through mechanisms such as sexual reproduction, genetic drift, mutation and natural selection. A key concept is that evolution occurs through changes in allele frequencies in populations over generations. The document also covers Mendelian inheritance, Darwinian evolution, the Hardy-Weinberg principle of genetic equilibrium, and factors that can lead to deviations from equilibrium, driving microevolutionary changes within populations.
The document discusses several key concepts related to microevolution and population genetics, including:
- Gene pools and allelic frequencies changing over time through mutations, gene flow, genetic drift, and non-random mating can cause microevolution.
- Hardy-Weinberg principle states that allele frequencies remain stable in a population not experiencing these evolutionary forces.
- Types of natural selection include directional, stabilizing, and disruptive selection.
- Speciation occurs when reproductive isolation leads to the splitting of one species into two or more distinct species over time. Mechanisms of isolation can be prezygotic or postzygotic.
Here are the solutions to the try these problems:
1. a) T allele frequency = (88/125) + (1/2)*(37/125) = 0.7
t allele frequency = 1 - 0.7 = 0.3
b) TT genotype frequency = 0.49, Tt genotype frequency = 0.42, tt genotype frequency = 0.09
2. p = 200/300 = 0.667, q = 100/300 = 0.333
3. a) Recessive allele frequency = 1/2500 = 0.0004
b) Dominant allele frequency = 1 - 0.0004 = 0.9996
c) Heterozygous
The document discusses the classification of organisms and the binomial system of nomenclature. It explains that all organisms are classified based on their characteristics and relationships. Each organism is assigned a genus and species name, with the genus indicating the broader group it belongs to. Classification sorts organisms into a hierarchy of taxonomic ranks including species, genus, family, order, class, phylum, and kingdom. The example of chimpanzees and their taxonomic classification is provided to illustrate this system.
This document discusses the use of genetic markers to characterize livestock breeds for conservation purposes. It explains that livestock breeds represent a valuable genetic resource but many are at risk of extinction. Molecular genetic characterization using DNA markers provides a precise way to measure genetic diversity and relationships between breeds. This can help prioritize breeds for conservation in order to maintain maximum genetic diversity.
Here are the solutions to the try these problems:
1. a) T allele frequency = (88/125) + (1/2)*(37/125) = 0.72
t allele frequency = 1 - 0.72 = 0.28
b) TT genotype frequency = 0.72^2 = 0.52
Tt genotype frequency = 2*0.72*0.28 = 0.48
tt genotype frequency = 0.28^2 = 0.08
2. p = 200/300 = 0.667
q = 1 - p = 0.333
3. a) Recessive allele frequency = √(1/2500) = 0.02
b
Hardy weinberg equilibrium and its consequences under different allelic syste...AnittaPulikanLionel
1) The document summarizes Hardy-Weinberg equilibrium, which states that gene and genotype frequencies in a population will remain constant from generation to generation if the population is large and there is no selection, migration, mutation, or non-random mating.
2) It describes the mathematical relationship between gene frequencies (p and q) and genotype frequencies (p^2, 2pq, q^2) known as the Hardy-Weinberg principle or the square law.
3) Several conditions must be met for a population to be in Hardy-Weinberg equilibrium including large population size, equal mating opportunities, no selection, migration, or mutation.
This document discusses different systems of mating and concepts related to inbreeding. It defines systems of mating as the rules by which gametes are chosen to form zygotes. Random mating is one system, while inbreeding occurs when relatives mate. Inbreeding can be measured at the individual level using the inbreeding coefficient (F), which represents an individual's probability of identity by descent. Inbreeding can also be measured at the population level using the inbreeding coefficient (f), which represents deviations from Hardy-Weinberg equilibrium. While F is calculated from pedigree data and ranges from 0 to 1, f is calculated from genotype frequencies and ranges from -1 to 1. The document contrasts F and f and provides examples of how different systems
B.sc. agri i pog unit 4 population geneticsRai University
This document provides an overview of population genetics and principles of evolution. It discusses how genetic variation is maintained in populations through mechanisms such as sexual reproduction, genetic drift, mutation and natural selection. A key concept is that evolution occurs through changes in allele frequencies in populations over generations. The document also covers Mendelian inheritance, Darwinian evolution, the Hardy-Weinberg principle of genetic equilibrium, and factors that can lead to deviations from equilibrium, driving microevolutionary changes within populations.
The document discusses several key concepts related to microevolution and population genetics, including:
- Gene pools and allelic frequencies changing over time through mutations, gene flow, genetic drift, and non-random mating can cause microevolution.
- Hardy-Weinberg principle states that allele frequencies remain stable in a population not experiencing these evolutionary forces.
- Types of natural selection include directional, stabilizing, and disruptive selection.
- Speciation occurs when reproductive isolation leads to the splitting of one species into two or more distinct species over time. Mechanisms of isolation can be prezygotic or postzygotic.
Here are the solutions to the try these problems:
1. a) T allele frequency = (88/125) + (1/2)*(37/125) = 0.7
t allele frequency = 1 - 0.7 = 0.3
b) TT genotype frequency = 0.49, Tt genotype frequency = 0.42, tt genotype frequency = 0.09
2. p = 200/300 = 0.667, q = 100/300 = 0.333
3. a) Recessive allele frequency = 1/2500 = 0.0004
b) Dominant allele frequency = 1 - 0.0004 = 0.9996
c) Heterozygous
The document discusses the classification of organisms and the binomial system of nomenclature. It explains that all organisms are classified based on their characteristics and relationships. Each organism is assigned a genus and species name, with the genus indicating the broader group it belongs to. Classification sorts organisms into a hierarchy of taxonomic ranks including species, genus, family, order, class, phylum, and kingdom. The example of chimpanzees and their taxonomic classification is provided to illustrate this system.
This document discusses the use of genetic markers to characterize livestock breeds for conservation purposes. It explains that livestock breeds represent a valuable genetic resource but many are at risk of extinction. Molecular genetic characterization using DNA markers provides a precise way to measure genetic diversity and relationships between breeds. This can help prioritize breeds for conservation in order to maintain maximum genetic diversity.
Here are the solutions to the try these problems:
1. a) T allele frequency = (88/125) + (1/2)*(37/125) = 0.72
t allele frequency = 1 - 0.72 = 0.28
b) TT genotype frequency = 0.72^2 = 0.52
Tt genotype frequency = 2*0.72*0.28 = 0.48
tt genotype frequency = 0.28^2 = 0.08
2. p = 200/300 = 0.667
q = 1 - p = 0.333
3. a) Recessive allele frequency = √(1/2500) = 0.02
b
Hardy weinberg equilibrium and its consequences under different allelic syste...AnittaPulikanLionel
1) The document summarizes Hardy-Weinberg equilibrium, which states that gene and genotype frequencies in a population will remain constant from generation to generation if the population is large and there is no selection, migration, mutation, or non-random mating.
2) It describes the mathematical relationship between gene frequencies (p and q) and genotype frequencies (p^2, 2pq, q^2) known as the Hardy-Weinberg principle or the square law.
3) Several conditions must be met for a population to be in Hardy-Weinberg equilibrium including large population size, equal mating opportunities, no selection, migration, or mutation.
This document discusses different systems of mating and concepts related to inbreeding. It defines systems of mating as the rules by which gametes are chosen to form zygotes. Random mating is one system, while inbreeding occurs when relatives mate. Inbreeding can be measured at the individual level using the inbreeding coefficient (F), which represents an individual's probability of identity by descent. Inbreeding can also be measured at the population level using the inbreeding coefficient (f), which represents deviations from Hardy-Weinberg equilibrium. While F is calculated from pedigree data and ranges from 0 to 1, f is calculated from genotype frequencies and ranges from -1 to 1. The document contrasts F and f and provides examples of how different systems
The document discusses a simulation of a population of bunnies in England, where some bunnies have a recessive allele that causes them to lack fur. Over generations, as the harsh winters cause the hairless bunnies to die off at higher rates, the frequency of the recessive allele decreases. The results demonstrate natural selection, as the recessive allele becomes less common as it confers a lower chance of survival in that environment.
Population genetics reconciled Darwin and Mendel's ideas by showing how natural selection could act on variation present in populations. The Hardy-Weinberg theorem describes genetic equilibrium in a population where allele frequencies remain constant between generations unless disrupted by factors like genetic drift, migration, non-random mating, mutation, or natural selection. These disruptions to equilibrium allow for microevolution and populations to change over time through natural selection acting on genetic variation.
The evolution of populations population geneticsStephanie Beck
This document discusses population genetics and the Hardy-Weinberg theorem. It defines key terms like population, gene pool, allele frequency, and microevolution. The Hardy-Weinberg theorem states that allele frequencies will remain constant between generations if a population is large, random mating occurs, there is no mutation, migration or natural selection. The document provides examples of how to use the Hardy-Weinberg equation to calculate allele frequencies and genotype proportions in populations.
The document discusses Hardy-Weinberg equilibrium, which states that allele and genotype frequencies in a population will remain constant from generation to generation if the population meets certain conditions. These conditions are large population size, random mating, no mutations, no migration, and no natural selection. The Hardy-Weinberg principle can be used to calculate expected genotype frequencies and serves as a baseline for detecting deviations caused by non-random mating, genetic drift, natural selection or other evolutionary forces.
This document discusses the Hardy-Weinberg law of genetic equilibrium. It states that in a large, randomly mating population, the frequencies of genotypes will remain constant from generation to generation in the absence of evolutionary influences like mutation, migration, genetic drift and non-random mating. The law establishes that the frequency of alleles A and a will be p and q, and the frequencies of genotypes AA, Aa and aa will be p^2, 2pq and q^2 respectively, where p + q = 1. The document provides examples of calculating genotype and gamete frequencies under Hardy-Weinberg equilibrium.
Five factors drive evolution in populations: mutation, migration, genetic drift, natural selection, and nonrandom mating. Genetic drift is the change in allele frequencies that occurs due to random sampling error in small populations. It can cause alleles to be lost or fixed in a population by chance alone, independent of adaptive effects. The rate of genetic drift is influenced by population size, with smaller populations experiencing stronger drift effects due to increased sampling error. Effective population size is often much smaller than actual population size due to factors like unequal sex ratios. Genetic drift reduces genetic diversity over time and can cause maladaptive evolution if drift is stronger than selection.
Ch 14 and 15 Genetics notes powerpoint.pptbashirlone123
This document discusses basic concepts in genetics and inheritance patterns. It defines key terms like genotype, phenotype, generations, alleles, dominant, recessive, homozygous, and heterozygous. It describes Gregor Mendel's experiments with pea plants and his discovery of the laws of segregation and independent assortment. It explains how to use Punnett squares and test crosses to predict inheritance. It also discusses exceptions to Mendelian genetics like incomplete dominance, codominance, pleiotropy, epistasis, polygenic traits, and sex-linked inheritance.
Hardy-Weinberg-Castle Principle of EquilibriumHenry Sergio Jr
The Hardy-Weinberg-Castle Principle states that under conditions of large population size, no mutation, no immigration or emigration, random mating, and random reproductive success, allelic and phenotypic frequencies will remain constant across generations. Natural populations rarely meet all these conditions, experiencing factors like non-random mating and selective pressures that drive evolution by changing frequencies over time. Studying this principle proves that natural selection is necessary for evolution and allows measurement of selective effects by comparing actual and expected allelic or phenotypic frequencies.
The document discusses the Hardy-Weinberg equation, which relates allele and genotype frequencies in a population at genetic equilibrium. It describes how the equation predicts that allele and genotype frequencies will remain constant from generation to generation if certain conditions are met, including no mutations, natural selection, migration, genetic drift or non-random mating. It provides examples of using the Hardy-Weinberg equation to calculate expected genotype and allele frequencies based on observed data from populations of horses and butterflies.
Population Genetics & Hardy - Weinberg Principle.pdfSuraj Singh
This document discusses population genetics and the Hardy-Weinberg principle of genetic equilibrium. It defines key terms like allele frequencies, genotype frequencies, and gene pools. It also describes how to calculate allele frequencies and genotype frequencies in a population. The document concludes by explaining that under certain conditions like a large panmictic population with random mating, the genetic structure will remain in equilibrium with allele and genotype frequencies remaining constant from generation to generation based on the Hardy-Weinberg principle.
This document provides information about population genetics and the Hardy-Weinberg principle of genetic equilibrium. It defines key population genetics concepts such as gene pool, allele frequencies, and genotypes. It describes the five conditions required for Hardy-Weinberg equilibrium: large population size, random mating, no mutations, no migration, and no natural selection. Examples are provided to demonstrate how to calculate allele and genotype frequencies using the Hardy-Weinberg equation.
Week 8.Notes. Population Genetics Problems and Answers_8b0c46d0f53e1b13996ca3...npalcober
This document discusses population genetics concepts including:
1. A genetic population is a group of interbreeding individuals characterized by gene and genotypic frequencies that make up the gene pool.
2. The Hardy-Weinberg equilibrium states that gene frequencies remain constant between generations if a population meets certain criteria.
3. Examples are provided to demonstrate calculating gene and genotypic frequencies for co-dominant and dominant traits, as well as dihybrid and sex-linked genes.
Foundations of Biological Sciences I Evolutionary Agents - 1 .docxbudbarber38650
Foundations of Biological Sciences I Evolutionary Agents - 1
A quick recap….
There are several terms that need to be clarified so that you can more easily follow the exercise. A gene is a
piece of DNA that directs the expression of a particular characteristic (trait). Genes are located on
chromosomes, and the location where a particular gene is found is referred to as the locus (plural: loci) of that
gene. An allele is a gene for which there is an alternative expression, which can lead to the alterative form of a
trait. For example, a diploid organism carries the allele “A” on one homologous chromosome, and the allele “A”
on the other. The genotype of this organism is then AA and it is said to be homozygous. An organism may also
carry two different alleles. For example on one chromosome it could carry the allele “A” and on the other it
could carry the allele “a”. The genotype of such an organisms is then Aa, and it is described as heterozygous for
this chromosomal locus.
The genotype of an organism is the listing of the two alleles for each trait that it possesses. The phenotype of an
organism is a description of the way a trait is displayed in the structure, behavior, or physiology of the organism.
Some alleles are dominant to others and mask the presence of other alleles. The dominant condition is indicated
by uppercase letters (e.g., “A”). The alleles that are masked are called recessive alleles. The recessive condition
is indicated by lowercase letters (e.g., “a”). When both dominants are present in the genotype (AA), the organism
is said to be homozygous dominant for the trait, and the organisms will show the dominant phenotype (trait
expression A). When both recessives are present in the genotype (aa), the organism is said to be homozygous
recessive for the trait, and the organisms will show the recessive phenotype (trait expression a). In the case of
complete dominance, the dominant allele completely masks the recessive allele, and an organism with a
heterozygous genotype (Aa) will show the dominant phenotype (trait expression A).
Evolutionary Agents
Evolution is a process resulting in changes in gene frequencies (= the genetic make-up) of a population over
time. The mechanisms of evolution include selection (which can cause change over time & adaptation), and
forces that provide variation and cause change over time (but not adaptation). Factors that change gene
frequencies over time are referred to as evolutionary agents.
A powerful way to detect the presence of evolutionary agents is the use of the Hardy–Weinberg model. This
model can be applied to traits that are influenced by several loci; the simplest case is for a trait that is regulated
by one locus with two alleles.
With the Hardy–Weinberg model, the frequency of genotypes in the population can be predicted from the
probability of encounters between gametes bearing the different alleles. With alleles R .
Population genetics deals with genetics at the level of populations rather than individuals. It considers the genetic composition of populations and how gene frequencies change over generations. The genetic constitution of a population is described by the proportion of individuals with each genotype and the transmission of genes from one generation to the next. Population genetics was first applied to genetic improvement in livestock. The Hardy-Weinberg law states that genotype and gene frequencies remain constant in a large, randomly mating population with no evolutionary influences. It provides a simple relationship between gene and genotype frequencies.
1) The document discusses the development of population genetics as an outgrowth of Mendelian genetics and the study of evolution. Early work in the 1900s established basic principles like the Hardy-Weinberg law of allele frequencies in populations.
2) Later researchers like Haldane analyzed the effects of factors like selection and population size on changing gene frequencies over generations. Work also examined the nature and origin of reproductive isolation between species.
3) Polyploidy, or the multiplication of chromosome sets, was found to be a common mechanism for reproductive isolation and the formation of new species, as it can restore fertility in interspecific hybrids.
AP BIOLOGY MENDELIAN GENETICS AND 2 Student Packet.pdfNancy Rinehart
Gregor Mendel conducted experiments on pea plants that demonstrated basic principles of heredity. He found that traits are transmitted through discrete factors (now called genes) and that these factors assort and segregate independently during the formation of gametes. Mendel's work established the foundations of classical or Mendelian genetics, including the laws of segregation and independent assortment. Later, scientists developed additional genetic concepts and tools, such as genetic linkage maps and the chi-square test, which allow for more sophisticated analysis of inheritance patterns.
This document provides an overview of genetics and key figures in the field. It discusses:
1) Important geneticists like Mendel, Morgan, and Bateson and their contributions to establishing genetics as a field.
2) Genetics concepts like genes, loci, chromosomes, and the three laws of genetics proposed by Mendel through experiments with pea plants.
3) Examples of genetic disorders and conditions like Down Syndrome, Turner Syndrome, and sickle cell anemia caused by abnormalities in chromosome number or structure.
The document discusses the completion of the Human Genome Project in 2000 and other genome projects for other species such as chicken, cow, pig, and more. It provides background on what a genome is, which is the complete sequence of all the known genes of an organism including their structure and function. It also discusses genetic mapping and how researchers determine the order and arrangement of genes on chromosomes through analyzing recombination frequencies during meiosis.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
The document discusses a simulation of a population of bunnies in England, where some bunnies have a recessive allele that causes them to lack fur. Over generations, as the harsh winters cause the hairless bunnies to die off at higher rates, the frequency of the recessive allele decreases. The results demonstrate natural selection, as the recessive allele becomes less common as it confers a lower chance of survival in that environment.
Population genetics reconciled Darwin and Mendel's ideas by showing how natural selection could act on variation present in populations. The Hardy-Weinberg theorem describes genetic equilibrium in a population where allele frequencies remain constant between generations unless disrupted by factors like genetic drift, migration, non-random mating, mutation, or natural selection. These disruptions to equilibrium allow for microevolution and populations to change over time through natural selection acting on genetic variation.
The evolution of populations population geneticsStephanie Beck
This document discusses population genetics and the Hardy-Weinberg theorem. It defines key terms like population, gene pool, allele frequency, and microevolution. The Hardy-Weinberg theorem states that allele frequencies will remain constant between generations if a population is large, random mating occurs, there is no mutation, migration or natural selection. The document provides examples of how to use the Hardy-Weinberg equation to calculate allele frequencies and genotype proportions in populations.
The document discusses Hardy-Weinberg equilibrium, which states that allele and genotype frequencies in a population will remain constant from generation to generation if the population meets certain conditions. These conditions are large population size, random mating, no mutations, no migration, and no natural selection. The Hardy-Weinberg principle can be used to calculate expected genotype frequencies and serves as a baseline for detecting deviations caused by non-random mating, genetic drift, natural selection or other evolutionary forces.
This document discusses the Hardy-Weinberg law of genetic equilibrium. It states that in a large, randomly mating population, the frequencies of genotypes will remain constant from generation to generation in the absence of evolutionary influences like mutation, migration, genetic drift and non-random mating. The law establishes that the frequency of alleles A and a will be p and q, and the frequencies of genotypes AA, Aa and aa will be p^2, 2pq and q^2 respectively, where p + q = 1. The document provides examples of calculating genotype and gamete frequencies under Hardy-Weinberg equilibrium.
Five factors drive evolution in populations: mutation, migration, genetic drift, natural selection, and nonrandom mating. Genetic drift is the change in allele frequencies that occurs due to random sampling error in small populations. It can cause alleles to be lost or fixed in a population by chance alone, independent of adaptive effects. The rate of genetic drift is influenced by population size, with smaller populations experiencing stronger drift effects due to increased sampling error. Effective population size is often much smaller than actual population size due to factors like unequal sex ratios. Genetic drift reduces genetic diversity over time and can cause maladaptive evolution if drift is stronger than selection.
Ch 14 and 15 Genetics notes powerpoint.pptbashirlone123
This document discusses basic concepts in genetics and inheritance patterns. It defines key terms like genotype, phenotype, generations, alleles, dominant, recessive, homozygous, and heterozygous. It describes Gregor Mendel's experiments with pea plants and his discovery of the laws of segregation and independent assortment. It explains how to use Punnett squares and test crosses to predict inheritance. It also discusses exceptions to Mendelian genetics like incomplete dominance, codominance, pleiotropy, epistasis, polygenic traits, and sex-linked inheritance.
Hardy-Weinberg-Castle Principle of EquilibriumHenry Sergio Jr
The Hardy-Weinberg-Castle Principle states that under conditions of large population size, no mutation, no immigration or emigration, random mating, and random reproductive success, allelic and phenotypic frequencies will remain constant across generations. Natural populations rarely meet all these conditions, experiencing factors like non-random mating and selective pressures that drive evolution by changing frequencies over time. Studying this principle proves that natural selection is necessary for evolution and allows measurement of selective effects by comparing actual and expected allelic or phenotypic frequencies.
The document discusses the Hardy-Weinberg equation, which relates allele and genotype frequencies in a population at genetic equilibrium. It describes how the equation predicts that allele and genotype frequencies will remain constant from generation to generation if certain conditions are met, including no mutations, natural selection, migration, genetic drift or non-random mating. It provides examples of using the Hardy-Weinberg equation to calculate expected genotype and allele frequencies based on observed data from populations of horses and butterflies.
Population Genetics & Hardy - Weinberg Principle.pdfSuraj Singh
This document discusses population genetics and the Hardy-Weinberg principle of genetic equilibrium. It defines key terms like allele frequencies, genotype frequencies, and gene pools. It also describes how to calculate allele frequencies and genotype frequencies in a population. The document concludes by explaining that under certain conditions like a large panmictic population with random mating, the genetic structure will remain in equilibrium with allele and genotype frequencies remaining constant from generation to generation based on the Hardy-Weinberg principle.
This document provides information about population genetics and the Hardy-Weinberg principle of genetic equilibrium. It defines key population genetics concepts such as gene pool, allele frequencies, and genotypes. It describes the five conditions required for Hardy-Weinberg equilibrium: large population size, random mating, no mutations, no migration, and no natural selection. Examples are provided to demonstrate how to calculate allele and genotype frequencies using the Hardy-Weinberg equation.
Week 8.Notes. Population Genetics Problems and Answers_8b0c46d0f53e1b13996ca3...npalcober
This document discusses population genetics concepts including:
1. A genetic population is a group of interbreeding individuals characterized by gene and genotypic frequencies that make up the gene pool.
2. The Hardy-Weinberg equilibrium states that gene frequencies remain constant between generations if a population meets certain criteria.
3. Examples are provided to demonstrate calculating gene and genotypic frequencies for co-dominant and dominant traits, as well as dihybrid and sex-linked genes.
Foundations of Biological Sciences I Evolutionary Agents - 1 .docxbudbarber38650
Foundations of Biological Sciences I Evolutionary Agents - 1
A quick recap….
There are several terms that need to be clarified so that you can more easily follow the exercise. A gene is a
piece of DNA that directs the expression of a particular characteristic (trait). Genes are located on
chromosomes, and the location where a particular gene is found is referred to as the locus (plural: loci) of that
gene. An allele is a gene for which there is an alternative expression, which can lead to the alterative form of a
trait. For example, a diploid organism carries the allele “A” on one homologous chromosome, and the allele “A”
on the other. The genotype of this organism is then AA and it is said to be homozygous. An organism may also
carry two different alleles. For example on one chromosome it could carry the allele “A” and on the other it
could carry the allele “a”. The genotype of such an organisms is then Aa, and it is described as heterozygous for
this chromosomal locus.
The genotype of an organism is the listing of the two alleles for each trait that it possesses. The phenotype of an
organism is a description of the way a trait is displayed in the structure, behavior, or physiology of the organism.
Some alleles are dominant to others and mask the presence of other alleles. The dominant condition is indicated
by uppercase letters (e.g., “A”). The alleles that are masked are called recessive alleles. The recessive condition
is indicated by lowercase letters (e.g., “a”). When both dominants are present in the genotype (AA), the organism
is said to be homozygous dominant for the trait, and the organisms will show the dominant phenotype (trait
expression A). When both recessives are present in the genotype (aa), the organism is said to be homozygous
recessive for the trait, and the organisms will show the recessive phenotype (trait expression a). In the case of
complete dominance, the dominant allele completely masks the recessive allele, and an organism with a
heterozygous genotype (Aa) will show the dominant phenotype (trait expression A).
Evolutionary Agents
Evolution is a process resulting in changes in gene frequencies (= the genetic make-up) of a population over
time. The mechanisms of evolution include selection (which can cause change over time & adaptation), and
forces that provide variation and cause change over time (but not adaptation). Factors that change gene
frequencies over time are referred to as evolutionary agents.
A powerful way to detect the presence of evolutionary agents is the use of the Hardy–Weinberg model. This
model can be applied to traits that are influenced by several loci; the simplest case is for a trait that is regulated
by one locus with two alleles.
With the Hardy–Weinberg model, the frequency of genotypes in the population can be predicted from the
probability of encounters between gametes bearing the different alleles. With alleles R .
Population genetics deals with genetics at the level of populations rather than individuals. It considers the genetic composition of populations and how gene frequencies change over generations. The genetic constitution of a population is described by the proportion of individuals with each genotype and the transmission of genes from one generation to the next. Population genetics was first applied to genetic improvement in livestock. The Hardy-Weinberg law states that genotype and gene frequencies remain constant in a large, randomly mating population with no evolutionary influences. It provides a simple relationship between gene and genotype frequencies.
1) The document discusses the development of population genetics as an outgrowth of Mendelian genetics and the study of evolution. Early work in the 1900s established basic principles like the Hardy-Weinberg law of allele frequencies in populations.
2) Later researchers like Haldane analyzed the effects of factors like selection and population size on changing gene frequencies over generations. Work also examined the nature and origin of reproductive isolation between species.
3) Polyploidy, or the multiplication of chromosome sets, was found to be a common mechanism for reproductive isolation and the formation of new species, as it can restore fertility in interspecific hybrids.
AP BIOLOGY MENDELIAN GENETICS AND 2 Student Packet.pdfNancy Rinehart
Gregor Mendel conducted experiments on pea plants that demonstrated basic principles of heredity. He found that traits are transmitted through discrete factors (now called genes) and that these factors assort and segregate independently during the formation of gametes. Mendel's work established the foundations of classical or Mendelian genetics, including the laws of segregation and independent assortment. Later, scientists developed additional genetic concepts and tools, such as genetic linkage maps and the chi-square test, which allow for more sophisticated analysis of inheritance patterns.
This document provides an overview of genetics and key figures in the field. It discusses:
1) Important geneticists like Mendel, Morgan, and Bateson and their contributions to establishing genetics as a field.
2) Genetics concepts like genes, loci, chromosomes, and the three laws of genetics proposed by Mendel through experiments with pea plants.
3) Examples of genetic disorders and conditions like Down Syndrome, Turner Syndrome, and sickle cell anemia caused by abnormalities in chromosome number or structure.
The document discusses the completion of the Human Genome Project in 2000 and other genome projects for other species such as chicken, cow, pig, and more. It provides background on what a genome is, which is the complete sequence of all the known genes of an organism including their structure and function. It also discusses genetic mapping and how researchers determine the order and arrangement of genes on chromosomes through analyzing recombination frequencies during meiosis.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
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Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
1. POPULATION GENETICS:
The study of the rules governing the
maintenance and transmission of
genetic variation in natural populations.
2. DARWINIAN EVOLUTION BY NATURAL SELECTION
Many more individuals are born than survive
(COMPETITION).
Individuals within species are variable (VARIATION).
Some of these variations are passed on to offspring
(HERITABILITY).
Survival and reproduction are not random. There must be a
correlation between fitness and phenotype.
3. Gregor Mendel
The “rediscovery” of Mendel’s genetic
studies in 1902 by William Bateson
completed the missing model for the
inheritance of genetic factors.
Mendel published his work in the
Transactions of the Brunn Society
of Natural History in 1866.
5. SEXUAL REPRODUCTION CONTRIBUTES TO VARIATION
Example – A Line Cross Experiment
Consider 2 diploid individuals with 3 loci and 2 alleles,
Parents: aabbcc x AABBCC
F1 progeny: AaBbCc
F2 progeny:
AABBCC AABBCc AABBcc
AABbCC AABbCc AABbcc
AAbbCC AAbbCc AAbbcc
AaBBCC AaBBCc AaBBcc
AaBbCC AaBbCc AaBbcc
AabbCC AabbCc Aabbcc
aaBBCC aaBBCc aaBBcc
aaBbCC aaBbCc aaBbcc
aabbCC aabbCc aabbcc
27
COMBINIATIONS
6. Mechanisms of Evolution: Mendelian Genetics
in Populations
Genetic variation is the raw material of evolutionary
change: how do we measure it?
What are the forces that cause genetic changes within
populations? That is, what mechanisms cause
evolutionary change?
7. Population Genetics
Evolution can be defined as a change in gene frequencies
through time.
Population genetics tracks the fate, across generations, of
Mendelian genes in populations.
Population genetics is concerned with whether a particular
allele or genotype will become more or less common over
time, and WHY.
8. A few things to keep in mind as we take an
excursion into population genetic theory:
“Make things as simple as possible, but no simpler.”
---Einstein
“All models are wrong, some are useful.”
---Box
“No theory should fit all the facts because some of the facts are
wrong.”
---Bohr
“Before I came here I was confused about this subject.
Having listened to your lecture I am still confused. But on a
higher level.”
---Fermi
9. Assumptions:
1) Diploid, autosomal locus with 2 alleles: A and a
2) Simple life cycle:
PARENTS GAMETES ZYGOTES
(DIPLIOD) (HAPLOID) (DIPLOID)
These parents produce a large gamete pool (Gene Pool) containing alleles
A and a.
a A A a
a A A a A a a
a A A a a A a A A
a a A A a a a
a A a a A A
A a A
10. Gamete (allele) Frequencies:
Freq(A) = p
Freq(a) = q
p + q = 1
Genotype Frequencies of 3 Possible Zygotes:
AA Aa aa
Freq (AA) = pA x pA = pA
2
Freq (Aa) = (pA x qa) + (qa x pA) = 2pAqa
Freq (aa) = qa x qa = qa
2
p2 + 2pq + q2 = 1
11. General Rule for Estimating Allele Frequencies
from Genotype Frequencies:
Genotypes: AA Aa aa
Frequency: p2 2pq q2
Frequency of the A allele:
p = p2 + ½ (2pq)
Frequency of the a allele:
q = q2 + ½ (2pq)
12. Sample Calculation: Allele Frequencies
Assume N = 200 indiv. in each of two populations 1 & 2
Pop 1 : 90 AA 40 Aa 70 aa
Pop 2 : 45 AA 130 Aa 25 aa
In Pop 1 :
p = p2 + ½ (2pq) = 90/200 + ½ (40/200) = 0.45 + 0.10 = 0.55
q = q2 + ½ (2pq) = 70/200 + ½ (40/200) = 0.35 + 0.10 = 0.45
In Pop 2 :
p = p2 + ½ (2pq) = 45/200 + ½ (130/200) = 0.225 + 0.325 = 0.55
q = q2 + ½ (2pq) = 25/200 + ½ (130/200) = 0.125 + 0.325 = 0.45
13. Main Points:
p + q = 1 (more generally, the sum of the allele
frequencies equals one)
p2 + 2pq +q2 = 1 (more generally, the sum of the
genotype frequencies equals one)
Two populations with markedly different genotype
frequencies can have the same allele frequencies
14. The Hardy-Castle-Weinberg Law
A single generation of random mating establishes H-W
equilibrium genotype frequencies, and neither these
frequencies nor the gene frequencies will change in
subsequent generations.
Hardy
p2 + 2pq + q2 = 1
15. H-W ASSUMPTIONS:
1) Mating is random (with respect to the locus).
2) The population is infinitely large. (no sampling error –
Random Genetic Drift)
3) Genes are not added from outside the population (no
gene flow or migration).
4) Genes do not change from one allelic state to another
(no mutation).
5) All individuals have equal probabilities of survival and
reproduction (no selection).
16. IMPLICATIONS OF THE H-W PRINCIPLE:
1) A random mating population with no external forces
acting on it will reach the equilibrium H-W frequencies
in a single generation, and these frequencies remain
constant there after.
2) Any perturbation of the gene frequencies leads to a
new equilibrium after random mating.
3) The amount of heterozygosity is maximized when the
gene frequencies are intermediate.
2pq has a maximum value of 0.5 when
p = q = 0.5
18. FOUR PRIMARY USES OF THE H-W PRINCIPLE:
1) Enables us to compute genotype frequencies from
generation to generation, even with selection.
2) Serves as a null model in tests for natural selection,
nonrandom mating, etc., by comparing observed to
expected genotype frequencies.
3) Forensic analysis.
4) Expected heterozygosity provides a useful means of
summarizing the molecular genetic diversity in natural
populations.
19. Color Pattern dominula medionigra bimaculata Total
Genotype B1B1 B1B2 B2B2
Sample Size (Nij) 905 78 3 N = 986
Frequency (Pij) 0.918 0.079 0.003 1.000
Allele Frequencies:
p1 = p11 + ½ p12 = 0.918 + ½ (0.079) = 0.958
p2 = 1 – p1 = 0.041
Expectations (Nij) p1
2 N 2p1p2 N p2
2 N
905 79 2
Genotype frequencies for Wing-color Polymorphism in a Natural
Population of the Moth Panaxia dominula (Fisher & Ford, 1947)
20. EVOLUTIONARY THOUGHT AFTER DARWIN
By the 1870s, most scientists accepted the historical reality of
evolution (and this has been true ever since).
It would be at least 60 years after the publication of The Origin of
Species before natural selection would come to be widely accepted.
People wanted life itself to be purposeful and creative, and
consequently did not find natural selection appealing.
Neo-Lamarckism -- inheritance of acquired characteristics.
Orthogenesis -- variation that arises is directed toward a goal.
Mutationism -- discrete variations are all that matter.
21. MUTATIONISM AND THE IMPACT OF MENDEL
Gregor Mendel’s research was published in 1866, but was not
noticed until 1900.
NOTE: Darwin knew nothing about the mechanism of inheritance
when he conceived of natural selection.
MUTATIONIST THEORIES (based on Mendel’s work):
Emphasized the importance of DISCRETE VARIATION
T. H. Morgan -- the founder of Drosophila genetics.
R. Goldschmidt -- theory of “hopeful monsters”.
Mendelian genetics disproved Lamarckian and blending
inheritance theories. However, the emphasis on
discrete variation caused a rift between mutation and
natural selection that was initially damaging to the field.
22. THE MODERN SYNTHESIS OF EVOLUTIONARY
BIOLOGY
The rift between genetics and natural selection was
resolved in the 1930s and 1940s.
This synthesis was forged from the contributions of
geneticists, systematists, and paleontologists.
23. Sir R. A. Fisher
1890-1962
The Genetical Theory
of Natural Selection
1930
Fisher united Mendelian
population genetics with
the inheritance of
continuous traits.
"The Correlation between Relatives on
the Supposition of Mendelian Inheritance"
Philosophical Transactions of the Royal
Society of Edinburgh in 1918, (volume 52,
pages 399–433).
24. J. B. S. Haldane
1892-1964
The Causes of Evolution
1932
Developed the mathematical
theory of gene frequency
change under selection (and
many other interesting
applications).
25. Sewall Wright
On his 90th birthday
1889-1988
Developed the mathematical
framework for understanding the
genetic consequences of
migration, effective population
size, population subdivision, and
conceived of the concept of
adaptive landscapes.
26. Outcomes of the “MODERN SYNTHESIS”
Populations contain genetic variation that arises by random mutation.
Populations evolve by changes in gene frequency.
Gene frequencies change through random genetic drift, gene flow,
and natural selection.
Most adaptive variants have small effects on the phenotype so
changes are typically gradual.
Diversification comes about through speciation.
28. MEASURING GENETIC VARIATION IN
NATURAL POPULATIONS
TWO COMMONLY USED MEASURES TO QUANTIFY GENETIC
VARIATION ARE:
P – the proportion of polymorphic loci (those that have 2 or
more alleles)
H – the average heterozygosity = proportion of loci at which
a randomly chosen individual is heterozygous.
31. SS FS FF
SS FS
FS FF
FF FS SS
Monomorphic locus: all individuals fixed for same allele
Polymorphic locus: 2 alleles
Frequency of F allele, p = 10 / 20 = 0.5
Frequency of S allele, q = 10 / 20 = 0.5
H = 4 /10 = 0.4
* * * *
32. ALLOZYME VARIATION IN MAJOR TAXA
In F. J. Ayala (ed.) 1976. Molecular Evolution. Sinauer Assoc.
36. SEQUENCE DATA
The definitive source of information regarding genetic
variation.
Usually obtained by PCR and direct sequencing of a
particular gene of interest.
Sequence-level variation can also be assessed using
restriction enzymes (RFLPs).
More on sequences when we get to “molecular evolution”.
37. THE EXTENSION OF H-W TO LOCI WITH MANY ALLELES
Regardless of the number of alleles per locus, the H-W
principle still applies as long as the organisms are diploid.
Assume that you have a locus with n alleles (A1, A2, … , An),
and the allele frequencies are given by p1, p2, p3, … , pn.
The expected frequency of any homozygote is just the
square of the allele frequency.
F (A1A1) = p1
2, F (A6A6) = p6
2, etc.
The expected frequency of any heterozygote is 2 times the
product of the respective allele frequencies.
F (A1A3) = 2p1p3, F (A3A5) = 2p3p5, etc.
Expected heterozygosity is 1 – Σ(pi
2).
38. With the recognition… that the… genome is replete with
DNA sequence polymorphisms such as RFLP’s, it was
only a small leap to imagine that DNA could, in
principle, provide the ultimate identifier.
E. S. Lander, 1991
DNA analysis will be to the end of the 20th century what
fingerprinting was to the 19th.
Melson, 1990
DNA POLYMORPHISM AS A TOOL FOR FORENSICS???
39. APPLICATIONS OF H-W TO FORENSICS
Example:
Defendant Genotype Tissue Sample From
Crime Scene
A14A27 A14A27
Question:
What is the probability of this match being a false
positive???
In other words what is the probability that this match
occurred simply by chance?
40. PROBABILITY OF A FALSE POSITIVE
Frequency of A14 in population = p14
Frequency of A27 in population = p27
Expected fraction of random individuals in the population
with the same genotype as the defendant = 2 p14 p27
PRODUCT RULE:
With multiple loci, the probability of a false positive is
simply equal to the product of the locus-specific
probabilities.
As this probability becomes small, we become more
confident that the match is real.
41. Highly repetitive blocks of DNA ( ) found
through out the genome.
DNA is cut with restriction enzymes ( ),
labeled with 32P and run through a gel to
reveal a characteristic banding pattern
INDIVIDUAL
A B C
VNTR Loci:
42. FROM: Balazs et al. 1989. Am. J. Hum. Genet. 44:182-190.
Balazs et al. 1992. Genetics 131:191-198
Genetic diversity of VNTR Loci in
Human Populations
Average heterozygosity of 6 VNTR
loci in ethnic groups:
Caucasian 0.89
Chinese 0.84
Cambodian 0.80
Melanesian 0.76
Australian aborigine 0.77
American
Blacks
Caucasians
Hispanics
43. Some Definitions:
Population: A freely interbreeding group of individuals.
Gene Pool: The sum total of genetic information present in a
population at any given point in time.
Phenotype: A morphological, physiological, biochemical, or
behavioral characteristic of an individual organism.
Genotype: The genetic constitution of an individual organism.
Locus: A site on a chromosome, or the gene that occupies the site.
Gene: A nucleic acid sequence that encodes a product with a distinct
function in the organism.
Allele: A particular form of a gene.
Gene (Allele) Frequency: The relative proportion of a particular
allele at a single locus in a population (a number between 0 and 1).
Genotype Frequency: The relative proportion of a particular
genotype in a population (a number between 0 and 1).