Scientific Method, Bias, and Evolutionary Theory

Defining Science

• A process of understanding phenomena through observation, generalization, and verification.
• Relies fundamentally on experiment and observation.

Understanding Scientific Claims

• Science makes **no claim** to have all the answers or to be right all the time.
• It claims that if we honestly, consistently, and vigorously pursue knowledge using scientific techniques, we will generate ever more accurate and consistent depictions and explanations of phenomena in our universe.

The Role of Bias in Observation

• Bias is a belief based on personal feelings.
• Observations can be biased by:
  • Existing knowledge or lack thereof.
  • Available technology.
  • Social trends and culture (*ethnocentrism* is a form of bias).

Science is Self-Correcting

• Science is not a perfect process, but it possesses the essential quality of being self-correcting.
• Scientific methodology is an exercise in rational thought and critical thinking.
• Continued observation and testing of a theory will eventually weed out any incorrect hypotheses.

Evolutionary Theory: Foundations of Modern Biology

Evolution is the change in the characteristics of a species over several generations, relying on the process of natural selection. The theory of evolution is based on the idea that all species are related and gradually change over time.

This scientific theory forms the basis of modern biology and physical anthropology.

Evidence Supporting Evolution (Tested for Over 150 Years)

The theory has been rigorously tested for over 150 years and has not been falsified. Key lines of evidence include:

1. Fossil Record

   Substantiated changes in species through time (e.g., *vestiges*: whales having hand-like bone structure in fins).

2. Age of Earth

   Lyell argued for the great age of the Earth based on observations of the natural world. Darwin employed this concept in his argument for gradualism.

3. Genetics

   As geneticists unraveled the “code of life,” an understanding of inheritance emerged, and a means of producing new genetic material—**mutation**—was found.

4. Observations of the Modern World

   All living species share fundamental commonalities. For example, all living species, from fungi to oak trees and from birds to people, carry their genetic information as DNA and use RNA to turn that information into proteins. Evolutionary theory predicts that these changes were brought about by selective breeding of domesticated plants and animals.

What is a Scientific Theory?

A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results.