Evolution Basics
The change in inherited traits in a population over generations
What is evolution?
Individuals in a population are not identical; they have different traits
What is (genetic) variation?
The formation of new species.
What is speciation?
Random changes in DNA
What are mutations?
Traits that help organisms survive and reproduce in their environment
What are adaptations?
The "fitness" of an organism is determined by how much it does this
What is reproduce?
A group of organisms that can successfully interbreed with each other and cannot breed with other groups
What is a species?
Movement of genes between populations.
What is gene flow or migration?
The process where individuals with beneficial traits survive and reproduce more.
What is natural selection?
Any environmental or biological factor that affects an organism’s ability to survive and reproduce
What is a selection pressure?
A single, shared ancestor that 2 or more species evolved from
What is a common ancestor?
Random change in allele frequencies due to chance.
What is genetic drift?
Mutations, migration, natural selection, and genetic drift
What are the mechanisms of evolution?
Natural selection leads to this.
What are adaptations?
Geological features, like mountains or rivers, can _________ populations, causing speciation.
What is isolate or separate?
Scientists look at anatomical traits, behavioral traits, and DNA to determine this.
What is the relatedness between species?
Natural selection and genetic drift both change the _____________ of a trait in a population.
What is frequency?
Natural Selection requires genetic variation, inheritance of traits, and this.
What is differential survival and reproduction?
These two species evolved during an interglacial period when one population got stuck on an icy island while the other population lived on a warmer, forested continent.
What are polar bears and brown bears?
Populations are more likely to survive environmental changes when they have more of this
What is genetic variation?