Bio 409 Facts, Theories, And Hypothesis


Published on

Published in: Technology, Education
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Bio 409 Facts, Theories, And Hypothesis

  1. 1. Facts, Theories, and Hypothesis Are they the same thing? Natural Selection is which one?
  2. 2. Scientific Fact <ul><li>Webster’s online dictionary defines a fact as “a piece of information presented as having objective reality” </li></ul><ul><ul><li>It is true universally </li></ul></ul><ul><ul><li>It does NOT try to give an explanation of an observation, but is the objective observation of a phenomenon </li></ul></ul>
  3. 3. Examples of scientific facts <ul><li>Air pressure at sea level 14.7 psi </li></ul><ul><li>The moon orbits the earth </li></ul><ul><li>Plants create food by the process of photosynthesis </li></ul>
  4. 4. Hypothesis <ul><li>Webster’s online dictionary states a hypothesis is “a tentative assumption made in order to draw out and test its logical or empirical consequences” </li></ul><ul><ul><li>A hypothesis attempts to explain a phenomenon, but still needs to be tested </li></ul></ul>
  5. 5. Example of hypothesis <ul><li>Observation: ground water is contaminated </li></ul><ul><li>Hypothesis: There is a leak in an underwater container holding gasoline. </li></ul><ul><ul><li>This possible explanation can be tested </li></ul></ul><ul><ul><ul><li>Examine the container to see if there is a leak </li></ul></ul></ul><ul><ul><ul><li>Examine the water to see if it contains the same type of gasoline held in the container </li></ul></ul></ul><ul><ul><ul><li>If the evidence supports the hypothesis, it is on its way to becoming a theory. </li></ul></ul></ul>
  6. 6. Scientific Theories <ul><li>According to Webster’s online dictionary a theory is “a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena” </li></ul><ul><ul><li>It is a hypothesis that has been tested, reviewed, and supported by many scientists under different circumstances </li></ul></ul><ul><ul><li>It tries to explain or interpret an observation </li></ul></ul><ul><ul><li>It is NOT proven, but supported </li></ul></ul>
  7. 7. Examples of scientific theories <ul><li>Gravitation Theory </li></ul><ul><ul><li>All objects with mass attract each other </li></ul></ul><ul><ul><ul><li>Einstein’s General Theory of Relativity would view gravity as the geometry of space and time, showing that neither theory can be considered fact as there are two very reasonable explanations for why objects behave the way they do when they fall </li></ul></ul></ul><ul><li>Germ Theory </li></ul><ul><ul><li>Microorganisms cause disease </li></ul></ul><ul><ul><ul><li>There are exceptions to this idea, but for the most part evidence supports this idea, making it theory </li></ul></ul></ul>
  8. 8. Natural Selection is… <ul><li>Natural Selection is NOT a fact because it is an explanation/interpretation of observations, not the actual universal reality </li></ul><ul><li>Natural Selection is NOT a HYPOTHESIS because it has been overwhelmingly tested and supported, making it a THEORY. </li></ul>
  9. 9. Conclusion <ul><li>Facts, theories, and hypothesis are NOT the same thing </li></ul><ul><li>Natural Selection is a scientific theory, since it has been tested, reviewed and supported by an abundance of evidence compiled from many scientists in many fields. </li></ul>