Bio. Lab Quiz 1 Background Flashcards
What is a population?
A group of individuals of the same species living in the same place at the same time
Does evolution act on populations or individuals?
Populations
What are two ways you can tell if evolution is happening?
- Subtle changes
2. Quantitative Methods
What is evolution?
A change in the inherited traits of a population of organisms from generation to generation; descent with modification through natural selection
What is a way evolution can be random?
Through genetic drift
What is a way evolution can be nonrandom?
Through selection
Evolution has no _____.
Goal
What is microevolution?
Studies changes within a single species population
What is macroevolution?
Studies changes that divide a population into species
What does Hardy-Weinberg do?
Test observations to see whether or not evolution is occurring
What are the five model assumptions of Hardy-Weinberg?
- Large Population (no genetic drift)
- Closed population (no immigration/emmigration)
- No Net mutations
- Random Mating
- No Natural selection
What are the two equations used in Hardy-Weinberg?
p + q = 1
p^2 + 2pq + q^2 = 1
p + q = 1 calculates what?
Allele frequencies
p^2 + 2pq + q^2 = 1 calculates what?
Genotype frequencies
What are the three effects of natural selection?
- Directional
- Disruptive
- Stabilizing
What does it mean if a population does not meet the five Hardy-Weinberg expectations?
Evolution is occuring
Hardy-Weinberg is a _____ model.
Null
What are the four ways a population can evolve?
- Natural Selection
- Genetic Drift
- Gene Flow
- Mutation
What do allelic frequencies help determine?
The change in a population’s overall genetic make up from one generation to the next
When in Hardy-Weinberg Equilibrium, do allelic frequencies change over time?
No
What is Natural Selection?
Process in which organisms with certain inherited characteristics are more likely to survive and reproduce than organisms with other characteristics
What two forces were simulated in lab 1?
Natural selection and genetic drift
What are the two reasons Hardy-Weinberg is used?
- To see if conditions are partially fulfilled
2. It is a null model to determine if evolution is occuring and allelic frequencies are changing
In the lab, the original gene pool was composed of what? What color was dominant and which was recessive?
50 red (dominant) beads and 50 yellow (recessive) beads
How was the frequency of A and the frequency of a calculated?
You calculate the total number of either the A or a allele, and divide by the total number of alleles. If there were 10 AA individuals and 10 Aa individuals, there are a total of 20 individuals and 40 alleles. To calculate F(A), you take the total number of A alleles (30) and divide by the total number of alleles (40).
If natural selection occured so that all aa individuals die, how do you calculate allele frequencies?
You calculate the total number of surviving alleles by doubling the total number of surviving individuals. Then, calculate allele frequencies by couting the total number of A and a alleles, ignoring aa individuals, and divide by the total number of alleles.
What does genetic drift mean?
Through random chance, gene frequencies change from generation to generation, even under Hardy-Weinberg assumptions
What are two types of genetic drift?
- Founder Effect
2. Bottleneck
What is Founder effect?
Occurs when a few individuals from an original population disperse and inhabit a new area.
What is a Population Bottleneck?
Occurs when a population is greatly reduced, then recovers
What parts of Hardy-Weinberg does bottleneck violate?
- large population
- No natural selection
What parts of Hardy-Weinberg does Founder Effect violate?
- Large population
- Closed population
________ is essential for evolution.
Variation
What is phenotypic plasticity?
When physical traits vary among individuals based on environmental pressures, not genotype
What two invertrebrates were simulated?
Oystercatchers and limpets
What were the two agents of mortality?
Oystercatchers and logs
Oystercatchers are ________ predators.
Visual