Population Genetics and Evolution

What does population genetics study?

The genetics of populations, focusing on the frequency of particular genes and genotypes.

What is transmission genetics concerned with?

Expected ratios of offspring genotypes based on the genotypes of the parents.

How is a population defined?

A community of interbreeding individuals localized in time and space that are members of a single species.

What is the definition of frequency in population genetics?

The proportion of all objects that are of a specific type within a population.

What is the formula for calculating frequency?

Frequency[X] = number of things that are X / total number of things.

What is the range of frequencies in a population?

Frequencies range from 0 to 1, and they sum to 1.

What happens to gene frequencies if certain individuals are prevented from breeding?

The frequency of genes in the population will change from one generation to the next.

How can new types of genes enter a population?

Through migration and mutation.

What is the rigorous definition of evolution?

A change in gene frequency from one generation to the next in a population.

What are the factors that can cause evolution to occur?

Mutation, migration, and circumstances that prevent individuals from reproducing.

What are the two types of circumstances that can prevent reproduction?

Non

What is the relationship between genes, genotypes, and phenotypes?

Genes combine into genotypes, which are responsible for building phenotypes (observable traits).

What does genetic drift refer to?

Random changes in gene frequency due to chance events, such as accidental death.

What does it mean if a population has evolved?

It has changed in genetic variation over generations.

What is the significance of the colored dots in the context of evolution?

Each dot represents a different individual, with color indicating a specific trait (phenotype) determined by genotype.

What is the role of natural selection in evolution?

It is a non

What is the lowest level of biological organization we track in population genetics?

Genes.

What is the outcome of evolution in terms of genetic variation?

A change in gene frequency in a population over generations.

How does fertilization relate to population genetics?

It is the process by which genes from parents combine to form a zygote, influencing future generations.

What is the importance of keeping track of gene frequencies?

It helps in understanding the evolutionary changes in a population.

What does the term 'phenotype' refer to?

The observable traits of an organism that are influenced by its genotype.

What is the relationship between mutation and evolution?

Mutations introduce new genes into a population, contributing to changes in gene frequency.

What is the significance of migration in population genetics?

Migration can introduce new genes into a population, affecting its genetic makeup.

What is the definition of evolution in terms of population genetics?

Evolution is the change in gene frequency in a population.

How did the genetic variation change from Generation 1 to Generation 150?

It changed from lots of genetic variation to little genetic variation.

What are the phenotypic traits observed in Generation 150?

A population with little genetic

What are the four main processes that can produce evolutionary change?

Mutation, migration, natural selection, and genetic drift.

How can mutation contribute to evolutionary change?

Mutation can cause changes in gene frequencies, potentially leading to a higher frequency of certain traits, like dark red color.

What role does migration play in evolutionary change?

Migration can introduce new individuals into a population, affecting the frequency of traits like dark red color.

How does natural selection influence evolutionary change?

Natural selection leads to non

What is an example of natural selection using rabbits?

Rabbits with coat

What is the relationship between fitness and natural selection?

Variation in traits is linked to fitness; high

What does genetic drift refer to in evolutionary terms?

Genetic drift refers to changes in gene frequencies due to random factors, leading to changes in trait prevalence by chance.

What distinguishes natural selection from genetic drift?

Natural selection is a non

What happens to dark red individuals in a population under natural selection?

Dark red individuals may increase in frequency due to their higher fitness and better survival rates.

What is the significance of selection pressure in evolution?

Selection pressure, such as predation, influences which traits are advantageous and thus shapes the evolution of a population.

How does genetic variation in a population affect evolution?

Higher genetic variation provides a broader range of traits that can be selected for or against, influencing evolutionary outcomes.

What is meant by 'non

random reproduction' in the context of natural selection?

What is the impact of low fitness on survival and reproduction?

Individuals with low fitness are less likely to survive and reproduce, leading to a decrease in their genetic contribution to future generations.

How can mutation lead to a high frequency of a trait in a population?

If mutations favor a particular trait, such as dark red color, the frequency of that trait can increase over generations.

What is the outcome of genetic drift in a small population?

In small populations, genetic drift can lead to significant changes in gene frequencies due to random events.

Why is natural selection considered a key mechanism of evolution?

Natural selection drives the adaptation of populations by favoring traits that enhance survival and reproduction.

How does the concept of fitness relate to evolutionary success?

Fitness determines an individual's ability to survive and reproduce, influencing the evolutionary trajectory of the population.

What does it mean for a trait to be heritable in the context of natural selection?

A heritable trait can be passed down from parents to offspring, allowing for the potential for evolutionary change through selection.

What role does chance play in genetic drift?

Chance events can randomly affect which individuals survive and reproduce, leading to changes in gene frequencies without regard to fitness.

What is genetic drift?

Changes in gene frequencies due to random factors.

What do the terms 'genetic' and 'drift' refer to in genetic drift?

'Genetic' refers to gene frequency, while 'drift' indicates the random fluctuation of genes at a locus.

How does genetic drift affect gene frequency in a population?

Gene frequency can fluctuate at random over time, independent of fitness.

What is an example of genetic drift in terms of survival?

If a high

How can random events influence genetic drift?

Random death or failure to reproduce can change gene frequency in each generation.

In what type of populations does genetic drift occur more rapidly?

Genetic drift happens faster in smaller populations compared to larger ones.

What is a founding population in the context of genetic drift?

A founding population has a different frequency of traits than the parent population due to random separation.

How does the environment influence the relationship between genotype and phenotype?

The environment can enhance or constrain the expression of a phenotype, affecting traits.

What factors can the environment include that influence phenotype?

Nutrition, temperature, exposure to sunlight, or toxins.

What is the general rule regarding the influence of the environment on traits?

The environment enhancing or constraining trait expression is the rule, not the exception.

How can variation in a phenotype, such as dimple size, occur?

Variation can occur due to environmental factors, such as sunlight exposure.

What happens to camouflage frogs in terms of genetic drift?

A camouflage frog may die by chance, affecting the gene frequency despite having higher fitness.

What is the relationship between genotype and phenotype?

Genotype influences phenotype, but this relationship can be affected by environmental factors.

What does the term 'accidental survival' mean in genetic drift?

It refers to survival and reproduction that occurs by chance rather than due to fitness advantages.

What is the significance of random events in genetic drift?

Random events can lead to significant changes in gene frequencies in a population.

What is an isolating event in genetic drift?

An event that separates a population, leading to different trait frequencies in the new population.

How does genetic drift relate to fitness?

Genetic drift can cause changes in gene frequency that are independent of the fitness of the genotypes.

What is the impact of random failure to reproduce on genetic drift?

It can lead to changes in gene frequency, contributing to genetic drift.

How does genetic drift differ from natural selection?

Genetic drift is random, while natural selection is based on fitness advantages.

What is an example of a genotype affecting phenotype?

The brown/brown genotype at the chin type locus results in a dimple on the chin.

How can environmental conditions lead to different phenotypes?

Different environmental conditions, such as sunlight exposure, can lead to variations in traits like dimple size.

What allele determines coat color in Siamese Cats?

The C allele.

How does temperature affect the coat color of Siamese Cats?

Colder extremities result in more dark coloration.

What is the difference between genotype and phenotype?

Genotype refers to the genetic makeup, while phenotype is the observable expression of traits.

What is it called when a single locus controls more than one trait?

Pleiotropy.

What are Mendelian traits?

Traits that are discrete and controlled by a single locus.

What is an example of a continuous trait?

Height.

What shape does the distribution of continuous traits typically resemble?

A bell

How do multiple loci contribute to a continuous trait?

Each gene at a locus contributes a small amount to the overall trait.

What are continuous traits also known as?

Polygenic traits.

How does the environment influence continuous traits?

It can cause variation in the phenotype for a given genotype.

What is directional selection?

A process where selection eliminates unfit individuals, shifting the trait distribution toward a higher value.

What happens during stabilizing selection?

Selection eliminates unfit individuals that are not average, shifting the distribution toward the average value.

What occurs during disruptive selection?

Selection eliminates unfit average individuals, shifting the distribution toward extreme values.

What is the relationship between continuous traits and genetic variation?

More genes contribute to the trait, leading to greater variation.

What is the significance of the bell curve in continuous traits?

It indicates that most individuals are average, with fewer individuals at the extremes.

What is the impact of selection on a population regarding continuous traits?

It non

What is the role of heritability in continuous traits?

It indicates that traits like height can be passed down through generations.

How does selection operate on height in a population?

Selection can favor taller individuals, average individuals, or even shorter individuals based on fitness.

What is the effect of multiple loci on the expression of a trait?

They contribute cumulatively to the phenotype, resulting in a range of expressions.

Why are many human traits considered continuous?

Because they are influenced by multiple genes and environmental factors.

What is the effect of environmental factors on phenotypes?

They can cause variations in traits even among individuals with the same genotype.

What does the term 'fitness' refer to in the context of selection?

The ability of an individual to survive and reproduce in its environment.

What does the term 'frequency' refer to in the context of trait distribution?

The proportion of individuals exhibiting a particular trait within a population.