Evidence for Evolution
How We Know Evolution Happens
Multiple independent lines of evidence
Evolution is supported by fossils, comparative anatomy, biogeography, embryology, direct observation, and molecular biology. These different sources point to the same basic conclusion.
Major evidence types
Fossils
- Show change through deep time
- Include transitional forms
DNA and proteins
- Reveal relatedness at the molecular level
- Can be used to compare species very precisely
Direct observation
Evolution can be observed directly in laboratory experiments, in breeding studies, and in natural populations, especially for organisms with short generation times.
Evidence works together
No single line of evidence is needed on its own; the strength of evolutionary biology comes from many independent observations fitting together.
Which of the following is evidence for evolution?
DNA similarity reflects shared ancestry.
Correct answer: DNA similarities among species
Name two different kinds of evidence for evolution.
Many answers are possible, such as fossils, anatomy, biogeography, or direct observation.
Correct answer: Fossils and DNA evidence.
Why are island species often interesting to evolutionary biologists?
Islands often isolate populations, allowing divergence and speciation.
Correct answer: They can show isolation and divergence