Darwin & Natural Selection
Who came up with the theory of evolution?
Charles Darwin
What are fossils?
Remains or traces of ancient organisms.
What is speciation?
Organisms that can mate and produce offspring
What is a gene?
A segment of DNA that codes for a protein or trait.
Where are the oldest fossils found — top or bottom rock layers?
Bottom
What does “natural selection” mean?
Survival of the fittest
What do similar embryos tell us?
That species may be related
What is it called when a mountain or river separates populations?
Geographic/allopatric speciation
What is a mutation?
A change in DNA
What does “extinct” mean?
The whole species is gone
What is it called when a living thing changes in order to have a better chance at survival?
Adaptation
What kind of structures look similar but function differently?
Homologous structures
What type of selection favors one extreme of a trait leading to a new species?
Directional Selection
What is a trait?
A characteristic or feature, like eye color or height.
Name one mechanism of evolution
Natural selection, mutation, genetic drift, migration, sexual selection
What island group did Darwin study finches on?
Galápagos Islands
What kind of body parts have no use today but did in the past?
Vestigial structures
What type of isolation is it when two populations live together but have different mating behaviors?
Behavioral Speciation
How are traits passed from parent to child?
Through genes (DNA) inherited from parents.
Name one type of selection
Disruptive, directional, stabilizing
What did Darwin notice about finches' beaks?
They were different on each island, based on food.
What does similar DNA between species tell us?
They share a common ancestor.
Name one condition that must be met for a population to stay in Hardy-Weinberg equilibrium and avoid speciation (no evolution).
No mutations, random mating, no migration, no natural selection, and large population size
What is the relationship between a gene and allele?
Allele is a version of that gene
What type of isolation is it when animals don’t mate at the same time?
Temporal isolation