Microevolution Flashcards
Define Population??
Members of a species that live in a defined geographic region at a given time.
Define species??
A group of organisms that can successfully breed with one another but not others.
Define Genotype??
Genetic makeup of an organism.
Define Phenotype??
Observable traits of an organism.
Define Alleles??
Variant forms of a gene. One from both parents.
- One organism usually has 2.
- Population has many (gene pool)
Define Gene Pool??
All the Alleles that exist in a population.
Define Microevolution??
Change of Allele frequency in a population over short periods of time??
Define Macroevolution??
Significant evolutionary change resulting in the formation of a new species.
Define Gene Flow??
Movement of genes from one population to another.
Define Migration??
Movement of individuals from one population to the territory of another.
Define Adaptation??
Modifications caused by Natural Selection over generations in response to environmental change.
Define Fitness??
Success of an organism in passing its genes to offspring relative to other members.
Define Theory of Evolution??
Change of frequency of alleles within a gene pool over time.
List the Principles of Evolution??
- Common Descent with Modification
- Natural Selection
Define Common Descent with Modifications??
Successive modifications of generations from a common ancestor, leading to new species.
Define Natural Selection??
Passing down of phenotypic traits that give a reproductive advantage. Most important mechanism for creating complex adaptations in nature.
List evolutionary processes??
- Variation: genetic variation caused by mutations, needed in sufficient amounts for natural selection to occur.
- Heredity: the transmission of genotypes from one generation to the next.
- Differential Reproduction: organisms best adapted to their environment are more likely to pass down genetic material in greater numbers than others.
Define Sexual Selection??
Mating based on Phenotype.
Define Adaptation??
Modifications over generations in response to environmental change.
Define Polygenic Traits??
A phenotype that is influenced by more than one gene.
3 modes of Natural Selection??
- Stabilizing Selection: genetic diversity decreases and population stabilizes in intermediate trait.
- Directional Selection: extreme phenotypes are favored causing shift in one direction.
- Disruptive Selection: main driving force behind new species arising. The movement of traits towards 2 opposite extremes, leading to 2 seperate species.
Define Mutations??
A change in alleles, causing new genetic information to arise.
- Can have no effect
- Alter product
- Prevent gene function
Define and list Point Mutations??
The replacement of a single nucleotide base with another.
- nonsense: converts amino codon to termination codon
- Missense: code for different amino
- Silent: codes for same amino. Has no noticeable effect.
Define Frameshift mutation??
INDEL of nucleotides, changing reading frame resulting in different Translation.
List Dominant Allele Mutations??
- Hypermorphic: increase in normal gene function (high levels of protein)
- Antimorphic: protein inactivates
- Neomorphic: gene function that’s different from normal function.
List Recessive Allele Mutations??
- Amorphic: complete loss of gene function.
- Hypomorph: partial loss of gene function
Define and list causes of Genetic Drift??
Chance alteration of allele frequency, affecting small populations greatly.
- Bottleneck Effect: allele frequency change by chance after sharp population decline.
- Founders Effect: migration, not survival, of small sub population to new area to start anew.
Define Gene Flow??
Transfer of Alleles or genes from one population to another through migration.
