Study sets, textbooks, questions
Upgrade to remove ads
Lecture 2: Microevolution and Genes Within Populations I
Terms in this set (50)
Are a set of genes that a progeny inherits from one parent
Morphology and behavior
-DNA sequence polymorphism
A unit of heredity that is transferred from a parent to an offspring
The genetic constitution of an individual organism
an either/or trait having a simple genetic basis
The set of observable characteristics of an individual organism
1997, evolutionary studies, Phenotypic Variation in Homo Sapiens
1933, population geneticist, Phenotypic variation in Harmonia axyridis (Asian ladybug)
PTC and PROP testing, allows you to observe a specific trait through taste. Human blood types also reveal variation (blood type O less common)
DNA gel, argarose, covered by a buffer. The sample of DNA moves toward the positive side of the gel and will show the similarity between genes
Hubby and Lewontin
1966, Enzyme polymorphisms, Adult Esterases from Drosophila pseudoobscra
DNA Sequence Polymorphism
mtDNA polymorphim in the Nothern Flicker, (Graham, Price, and Moore 1991)
Single Gene Locus
-Allele A is dominant
-Allele a is recessive
p (A) + q(A) = 1
All the frequencies must add up to one
William Castle (1903) and Karl Pearson (1904) introduced the concepts. Hardy and Weinberg (1908) generalized their results.
What did Hardy and Weinberg demonstrate with their equation?
Random mating and meiosis do not cause evolutionary change.
-Dominant alleles do not increase in frequency at the expense of recessive genes
Hardy-Weinberg and a Constant Population (Five Assumptions)
1. No mutation takes place
2. No genes are transferred to or from other sources
3. Random mating is occurring
4. The population is very large
5. No selection occurs
-Assume a population of genes
-Allelic frequencies (=gene frequencies)
-Genotypic frequencies (=zygotic frequencies)
Allelic frequencies depend only upon allelic frequencies of the previous generation, and the genotypic frequencies produced through random mating depend upon the allelic frequencies
Single Locus, Two Allele Model
A and a are alleles at single locus.
p + q = 1
Genotypic Frequencies Equation
P + Q + R = 1
Estimate Allelic Frequencies Equation
P>A = P>AA + 1/2Q>Aa
Hardy-Weinberg Relationship Male and Female
Male: p + q = 1
Female: p + q = 1
What type of diagram simulates random mating?
A multiplication matrix
Random Mating Hardy-Weinberg Equation
p^2 + 2pq + q^2
Once in ______________________, the population will remain the same as long as ____________ occurs and perturbing forces are nonexistent.
Equilibrium, random mating
4. Non random mating
5. Genetic drift
Does random mating change allele frequencies?
Five Agents of Evolutionary Change
2. Gene Flow
3. Nonrandom mating
4. Genetic drift
Can alter gene frequencies, but are such changes trivial or significant. By itself it is trivial
The movement of genes from one breeding population another. Large changes can be made (gene frequencies, gene flow in gametes)
Tasters and nontasters
When there are less heterozygotes than homozygous individuals (Walen Defect)
Mating between two individuals is influenced by genotype or phenotype. Individuals do not choose potential mates.
A type of nonrandom mating. Individuals with similar genotypes or phenotypes mate with each other more frequently than would be expected under random mating.
A type of nonrandom mating. Individuals with dissimilar genotypes and phenotypes mate with each other more frequently that would expected under random mating
Random allelic frequency changes, occurs in small populations, potential for causing large changes in gene frequencies
What are the three ways that genetic drift can occur?
1. Founder Effect
2. Bottle Neck Effect
3. Continuous drift in small populations
A population initiated by a small group of founders. Inbreeding and genetic drift occurs when the population is still small.
Bottle Neck Effect
Loss of genetic variation over time, sharp reduction in the size of a population due to environmental events
Differential reproduction in a genetically diverse population. It occurs when one genotype leaves a different number of progeny than another
The one genotype leaving the greatest number of offspring
Three Conditions for Natural Selection to Occur
1. Variation must exist
2. Variation of individuals must result in differences in the number of offspring surviving
3. Variation must be heritable
What is the only agent that produces adaptive evolutionary changes?
Sets with similar terms
BIO Ch 23
Biology Chapter 23
Ch. 23 The Evolution of Populations
Evolution of Populations (Exam 1)
Other sets by this creator
Wildlife Diseases (Categories)
Wildlife Disease Exam I review
Wildlife Disease (Diseases)
'Renal Physiology Exam 4