What is Science? Textbook Chapter 1

What is Science?

• Defined as knowledge gained through study, observation, or experimentation.
• Refers to both the process of acquiring knowledge and the body of knowledge amassed.

Scientific Approaches in Biology

• Two primary scientific approaches: Discovery Science and Hypothesis-Based Science.

Discovery Science

• Involves verifiable observations and measurements.
• Conclusions derived using inductive reasoning, which draws generalizations from specific observations.
• Example: All biological specimens observed over time contain cells, leading to the conclusion that all living things are composed of cells.

Hypothesis-Based Science

• Elicited from observations and questions about causes and explanations.
• Development of a hypothesis: a suggested explanation for observations.
• Hypotheses are tested through additional observations and designed experiments.

Deductive Reasoning

• Moves from generalizations to specific conclusions based on premises.
• Example:
  • Premise #1: All living things are composed of cells.
  • Premise #2: Human beings are living.
  • Conclusion: Human beings must be composed of cells.

Theory vs Hypothesis

• A theory is broad, explaining multiple observations and supported by substantial evidence.
• Hypotheses are narrower and specific, requiring clear testing and potential falsification.

Example of Hypothesis-Based Science

• Scenario: A flashlight is not working.
• Hypotheses:
  • Hypothesis #1: Batteries may be dead.
  • Hypothesis #2: Bulb may be burnt out.

If-Then Logic

• Used in testing hypotheses to generate predictions.
  • If batteries are dead, replacing them should restore function.
  • If the bulb is burnt out, replacing it should also restore function.

Requirements for a Valid Hypothesis

• Must be testable: there should be a method to evaluate its correctness.
• Must be falsifiable: experiments must be able to prove it false.
• Hypotheses cannot be proven with absolute certainty but gain support if they survive attempts at disproval.

Case Study in Hypothesis-Based Science

• Observation: Many poisonous animals exhibit bright colors to warn predators, which may save them from being eaten.
• Hypothesis: Mimicry in non-poisonous animals reduces the likelihood of predation by resembling poisonous ones.

Testing the Hypothesis

• Predators are expected to avoid brightly colored snakes; the prediction is that non-poisonous snakes will be attacked more when poisonous snakes are absent.
• Experiment involves two snake types: brightly colored and plain brown fake snakes.
• Both types are placed in areas with varying presence of poisonous snakes to observe predator behavior.