The Nature of Science Truth Proof Belief Evidence Debate Consensus

What is a scientific theory?

• “Theory” has a different meaning in science than in everyday life.
• In science, a Theory is NOT just a good idea!
• A Scientific Theory:
• Explains a wide variety of observations with a few simple principles, AND
• Must be supported by a large, compelling body of evidence.
• Must NOT have failed any crucial test of its validity.

Which of the following is true of Darwin’s Theory of Evolution by Natural Selection?

• A small but vocal minority of scientists believe that the theory of evolution is true
• Scientific opinion is about evenly split as to whether evolution really explains the diversity of life on Earth.
• Scientific opinion runs about 90% in favor of the theory of evolution and about 10% opposed.
• While widely accepted by most scientists, there would still be “reasonable doubt” about whether evolution is true -- Judicial proof is much harder to achieve than scientific proof.
• None of the above: evolution is the only plausible explanation for the diversity of life on earth.