Lab Manual 3+4

Flashcards covering key vocabulary related to experimental design for stripe counting, pill bug population studies, and fundamental concepts in population genetics and evolutionary mechanisms like Hardy-Weinberg equilibrium, migration, genetic drift, nonrandom mating, mutation, and selection.

Symmetrical Distribution (Bell-shaped)

A distribution of data that looks balanced or like a bell curve.

Range (Data)

The difference between the largest and smallest observed numbers of a particular trait.

Data Bin

A grouping of a range of stripe numbers (or other data), where each bin holds seeds (or data points) of a certain type or range.

Bird-style Predators (Simulation)

Simulated predators using tongs, meant to simulate a long bird beak that would pinch a pill bug prey item.

Rodent-style Predators (Simulation)

Simulated predators using a two-pronged fork, meant to simulate a rodent paw that would scoop up a pill bug.

Survivor (Predation Trial)

A pill bug that evades capture during a predation trial.

Victim (Predation Trial)

A pill bug that is collected and deposited in the capture area during a predation trial.

Evolution

Change through time in a population (rather than an individual) over time, specifically defined as changes in allele frequencies.

Allele Frequencies

How many copies of a given allele are present in a given population.

Allele

A version of a gene (e.g., A1 and A2).

Dominant Allele

By convention, typically labeled as A1 in a two-allele scenario.

Recessive Allele

By convention, typically labeled as A2 in a two-allele scenario.

Fixed Population (Allele)

A population where an allele has a frequency of 1, meaning all alleles in the population are that specific allele and there is no variation for that trait.

Genotype Frequencies

Calculated by counting the number of individuals with each genotype to derive allele frequencies.

p

Denotes the frequency of the A1 (dominant) allele in a population (fA1).

q

Denotes the frequency of the A2 (recessive) allele in a population (fA2).

p²

Represents the frequency of homozygous dominants (fA1A1) in a population, assuming Hardy-Weinberg equilibrium.

q²

Represents the frequency of homozygous recessives (fA2A2) in a population, assuming Hardy-Weinberg equilibrium.

2pq

Represents the frequency of heterozygotes (fA1A2) in a population, assuming Hardy-Weinberg equilibrium.

Hardy-Weinberg Equilibrium

A scenario under which allele frequencies would not change, meaning the population is not evolving. This state requires specific conditions to be met.

Conditions for Hardy-Weinberg Equilibrium

No migration, an 'infinitely' large population, random mating, no mutation, and equal survival/reproduction for all genotypes.

Microevolutionary Mechanisms

The five ways that allele frequencies can change in a population: migration, genetic drift, nonrandom mating, mutation, and selection.

Migration (Microevolution)

When members of a different population join the focus population, leading to a change in allele frequencies.

Genetic Drift

The change in allele frequencies due to random sampling or chance events, most relevant in small populations.

Nonrandom Mating

Mating patterns where individuals do not have an equal chance of mating with every other individual, affecting genotype frequencies.

Mutation (Microevolution)

The change in alleles; specifically refers to forward (A1 to A2) and backward (A2 to A1) mutation rates in a two-allele system.

Selection (Microevolution)

Differences in survival or reproduction levels among different genotypes, leading to changes in allele frequencies.

POP!World

Simulation software used to model evolution at a single gene in a single population.

Basic Mode (POP!World)

A simulation mode where no evolutionary forces are at work, meaning the population will be in Hardy-Weinberg equilibrium.

Focus Population (Migration Module)

The population of primary interest in the migration simulation.

Donor Population (Migration Module)

A population from which migrants enter the focus population in the simulation.

Fraction of Migrants (m)

The proportion of the total focus population each generation that is from the donor population.

Founder Effects

A type of genetic drift that occurs when a small group leaves a larger population and begins a new population elsewhere.

Bottleneck Effects

A type of genetic drift that occurs when some outside force eliminates a large portion of a previously large population.

Fixation (Genetic Drift)

When an allele's frequency reaches 1 (or 0, meaning it is lost) within the population due to random chance.

Frequency of Inbreeding (F)

A variable measuring the randomness of mating, where a higher F indicates a higher level of nonrandom mating.

Forward Mutation

The mutation rate from allele A1 to allele A2, by convention.

Backward Mutation

The mutation rate from allele A2 to allele A1, by convention.

Fitness (Absolute Fitness)

The average number of offspring individuals of a given genotype produce.

Relative Fitness

A measure of fitness calculated by comparing the average number of offspring from all genotypes and dividing the average for each genotype by the highest number of offspring from any of the genotypes.

Heterozygote Advantage

A simulation outcome where the heterozygote genotype has the highest fitness.