Darwin & Natural Selection
Who came up with the theory of evolution?
Charles Darwin
What are fossils?
Remains or traces of ancient organisms.
Where are the oldest fossils found — top or bottom rock layers?
Bottom
What is a gene?
A segment of DNA that codes for a protein or trait.
What’s one thing that can cause evolution?
Natural selection, mutations, genetic drift, etc.
What does “natural selection” mean?
Nature picks the best traits to survive.
What do similar embryos tell us?
That species may be related
What kind of rock are fossils usually found in?
Sedimentary rock
What is a mutation?
A change in DNA
What does “extinct” mean?
The whole species is gone
What does "survival of the fittest" mean?
The best-adapted organisms survive and reproduce.
What kind of structures look alike but do different things?
Homologous structures
What is the name for the timeline of Earth's life history?
Geologic Time Scale
What is a trait?
A characteristic or feature, like eye color or height.
Name one mechanism of evolution besides natural selection.
Mutation, 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 is one way scientists figure out the exact age of a fossil?
Radioactive dating
How are traits passed from parent to child?
Through genes (DNA) inherited from parents.
What is speciation?
When new species forms
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.
What is an index fossil used for?
To compare the age of rock layers around the world
How do mutations affect traits?
Mutations can change genes, which can result in new traits.
What type of isolation is it when animals don’t mate at the same time?
Temporal isolation