BIOL 1407 Final Exam Questions with Correct
Answers
What is evolution?
The change in genetic composition of populations over time.
What drives the origin and extinction of species?
Genetic changes observed through evolution.
What are the three propositions of Darwin's theory of evolutionary change?
1. Species change over time. 2. Divergent species share a common ancestor. 3. Natural
selection is the mechanism of change.
What is natural selection?
The differential survival and reproduction of individuals based on variation in their traits.
How do humans practice artificial selection?
By breeding plants and animals with desired characteristics.
What is a population in the context of evolution?
A group of individuals of a single species that live and interbreed in a particular geographic
area.
Do individuals evolve?
No, populations evolve, not individuals.
What is mutation in evolutionary biology?
Any change in the nucleotide sequences of DNA that serves as the origin of genetic variation.
,Are mutations random with respect to the needs of an organism?
Yes, mutations are random; selection acts on the random variation resulting in adaptation.
What is genetic drift?
Random changes in allele frequencies that can influence populations, particularly small ones.
What is the founder effect?
A phenomenon where a small group colonizes a new area, leading to a loss of genetic
variation.
What is stabilizing selection?
A type of natural selection that preserves the average phenotype.
What is directional selection?
Natural selection that favors individuals varying in one direction from the mean.
What is disruptive selection?
Natural selection that favors individuals varying in both directions from the mean.
What defines a species?
Groups of organisms that share genetic and morphological attributes and are reproductively
isolated from other groups.
What is the morphological species concept?
Defining species based on their appearance.
What is the biological species concept?
, Groups of actually or potentially interbreeding populations that are reproductively isolated
from other such groups.
What is the lineage species concept?
Species as branches on the tree of life, including asexually reproducing species.
What is allopatric speciation?
Speciation that occurs when populations are separated by a physical barrier.
What can lead to speciation?
Genetic changes preventing reproduction between formerly interbreeding populations.
What is gene flow?
The transfer of genetic variation from one population to another.
What is the role of genetic variation in evolution?
It is essential for natural selection to occur.
What happens to populations that experience gene flow?
They become more genetically similar to one another over generations.
What is the impact of genetic drift on small populations?
It can lead to significant fluctuations in allele frequencies.
What is the significance of a population bottleneck?
It reduces genetic diversity and can lead to increased frequency of harmful alleles.
How does natural selection affect quantitative traits?
It can act in stabilizing, directional, or disruptive ways.
Answers
What is evolution?
The change in genetic composition of populations over time.
What drives the origin and extinction of species?
Genetic changes observed through evolution.
What are the three propositions of Darwin's theory of evolutionary change?
1. Species change over time. 2. Divergent species share a common ancestor. 3. Natural
selection is the mechanism of change.
What is natural selection?
The differential survival and reproduction of individuals based on variation in their traits.
How do humans practice artificial selection?
By breeding plants and animals with desired characteristics.
What is a population in the context of evolution?
A group of individuals of a single species that live and interbreed in a particular geographic
area.
Do individuals evolve?
No, populations evolve, not individuals.
What is mutation in evolutionary biology?
Any change in the nucleotide sequences of DNA that serves as the origin of genetic variation.
,Are mutations random with respect to the needs of an organism?
Yes, mutations are random; selection acts on the random variation resulting in adaptation.
What is genetic drift?
Random changes in allele frequencies that can influence populations, particularly small ones.
What is the founder effect?
A phenomenon where a small group colonizes a new area, leading to a loss of genetic
variation.
What is stabilizing selection?
A type of natural selection that preserves the average phenotype.
What is directional selection?
Natural selection that favors individuals varying in one direction from the mean.
What is disruptive selection?
Natural selection that favors individuals varying in both directions from the mean.
What defines a species?
Groups of organisms that share genetic and morphological attributes and are reproductively
isolated from other groups.
What is the morphological species concept?
Defining species based on their appearance.
What is the biological species concept?
, Groups of actually or potentially interbreeding populations that are reproductively isolated
from other such groups.
What is the lineage species concept?
Species as branches on the tree of life, including asexually reproducing species.
What is allopatric speciation?
Speciation that occurs when populations are separated by a physical barrier.
What can lead to speciation?
Genetic changes preventing reproduction between formerly interbreeding populations.
What is gene flow?
The transfer of genetic variation from one population to another.
What is the role of genetic variation in evolution?
It is essential for natural selection to occur.
What happens to populations that experience gene flow?
They become more genetically similar to one another over generations.
What is the impact of genetic drift on small populations?
It can lead to significant fluctuations in allele frequencies.
What is the significance of a population bottleneck?
It reduces genetic diversity and can lead to increased frequency of harmful alleles.
How does natural selection affect quantitative traits?
It can act in stabilizing, directional, or disruptive ways.
