Bio 109 Finals Prep -Questions and Correct
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Population
Groups of individuals of the same species, often isolated by geography
Evolution
Change in characteristics of a population over generations.
Natural Selection
The physical or behavioral traits of organisms that lead to increased survival or reproduction
become more common in a population
(Process where populations adapt to their changing environment)
4 Mechanisms of Evolution
1. Mutation
2. Genetic drift
3. Migration/gene flow
4. Natural selection
Founder Effect
Small population founds new, isolated population, founders have different allele frequencies than
original population
Population Bottleneck
,Catastrophic event, many individuals die. The ones left aren't representative of original
population's allele frequencies.
Mutation
Direct change in DNA. Can create new allele.
Gene Flow/ Migration
Movement of genes from one population to another. Can alter allele frequencies.
Most important cause of evolution
Natural Selection
Fitness
The amount of offspring an individual produces; relative survival and reproduction of one
variant
Adaptation
Traits that increase fitness of an individual in a particular environment. May increase number of
offspring produced.
Artificial Selection
Human choice. Examples: breeding dogs, choosing most desirable trait for crops
Rules of Natural Selection
, 1. Population evolves; individual doesn't
2. Trait must already be in gene pool
3. Goal is NOT to create a "super organism"
Directional Selection
Causes population traits to move in certain direction.
(Example: giraffe's necks become longer over time, brown moths are selected over white moths)
Stabilizing Selection
Extremes selected against, average traits remain. Populations resist change in stable
environments. (Example: human birth weight)
Diversifying Selection
Extremes are preferred, evolution of population with 2 + variants. Primary way new species
arise.
Sexual Selection
Trait influences likelihood of mating
(Explains male/female differences in many species--sexual dimorphism).
Assortive Mating
Preference for an organism to mate with someone like itself.
(Exaggerates physical differences between groups--ex: tall women marrying tall men)
Anotomical Homology
The study of similar structures on organisms to determine a common ancestor.
Answers Guaranteed A+!
Population
Groups of individuals of the same species, often isolated by geography
Evolution
Change in characteristics of a population over generations.
Natural Selection
The physical or behavioral traits of organisms that lead to increased survival or reproduction
become more common in a population
(Process where populations adapt to their changing environment)
4 Mechanisms of Evolution
1. Mutation
2. Genetic drift
3. Migration/gene flow
4. Natural selection
Founder Effect
Small population founds new, isolated population, founders have different allele frequencies than
original population
Population Bottleneck
,Catastrophic event, many individuals die. The ones left aren't representative of original
population's allele frequencies.
Mutation
Direct change in DNA. Can create new allele.
Gene Flow/ Migration
Movement of genes from one population to another. Can alter allele frequencies.
Most important cause of evolution
Natural Selection
Fitness
The amount of offspring an individual produces; relative survival and reproduction of one
variant
Adaptation
Traits that increase fitness of an individual in a particular environment. May increase number of
offspring produced.
Artificial Selection
Human choice. Examples: breeding dogs, choosing most desirable trait for crops
Rules of Natural Selection
, 1. Population evolves; individual doesn't
2. Trait must already be in gene pool
3. Goal is NOT to create a "super organism"
Directional Selection
Causes population traits to move in certain direction.
(Example: giraffe's necks become longer over time, brown moths are selected over white moths)
Stabilizing Selection
Extremes selected against, average traits remain. Populations resist change in stable
environments. (Example: human birth weight)
Diversifying Selection
Extremes are preferred, evolution of population with 2 + variants. Primary way new species
arise.
Sexual Selection
Trait influences likelihood of mating
(Explains male/female differences in many species--sexual dimorphism).
Assortive Mating
Preference for an organism to mate with someone like itself.
(Exaggerates physical differences between groups--ex: tall women marrying tall men)
Anotomical Homology
The study of similar structures on organisms to determine a common ancestor.
