Unit 6. Evolution Flashcards
Define evolution.
The biological change in populations over time
List the 4 principles of natural selection.
Overproduction, Variation, Adaptation, and Descent with modification
What is an adaptation?
A feature that allows organisms to survive in an environment
List 3 sources of genetic variation.
Random mutations, genetic recombination during meiosis (crossing over) and migration (gene flow)
Natural Selection acts on traits that are what?
Determined by a polygenic trait
Well-adapted individuals survive and produce what?
Offsprings
If the environment mice live in is light brown dirt, what type of selection would occur?
Natural Selection
If the environment mice live in is medium dirt, what type of selection would occur?
Natural selection
What type of selection would occur if the environment mice live in can be light dirt OR dark dirt? Explain how the environment affects survival.
Natural Selection. Environment reduces the number of organisms that actually survive the new conditions.
What is convergent evolution?
When unrelated species evolve similar characteristics because they live in the same environment
What is divergent evolution?
When species arise from one common ancestor, the environment causes differences to evolve in population
Which pattern of evolution results in slow change over time?
Gradualism
Explain the difference between what would cause gradual extinction vs. mass extinction.
Gradual extinction occurs at a slow rate, so climate change, and natural disasters. Mass extinction is what happens suddenly, so massive volcanoes, meteor, or tsunami.
What is an example of coevolution?
Where species affect each other’s evolution.
Who is better at surviving in changing environments – sexual reproducers or asexual reproducers? Explain.
Sexual reproducers because they produce a combination of genes in the offspring that make it easier to survive in the environment for them.
