Introduction to Zoology BIO 2215 Oklahoma City Community College Dennis Anderson

Zoology Scientific study of the diversity of animal life

Why Study Zoology?

Understand the natural world

Learn to protect the environment

Develop skills for learning

Myths To Explain Biological Processes Disease caused by evil spirits Brain produces snot Blood determines heredity Heart is for emotions

How Does Science Separate Myths from Reality? Scientific Method

Scientific Method Observation Hypothesis Test Hypothesis Conclusion Prediction Test Hypothesis Experiment Further Observations Conclusion

Edward Jenner 1749-1823 Smallpox Scientific method

Observation Smallpox is deadly

Observation Survivors are immune

Observation Milkmaids do not get smallpox

Observation Milkmaids get cowpox from cows

Cowpox Makes You Immune to Smallpox Hypothesis Cowpox Makes You Immune to Smallpox

Prediction If you are exposed to cowpox, you will be immune to smallpox

Experiment

Results Boy did not get smallpox

Conclusion Hypothesis supported

Robert Koch 1843-1910 Identified the bacterium that causes anthrax Identified the bacterium that causes tuberculosis

Louis Pasteur 1822-1895 Developed vaccines for rabies and anthrax Demonstrated the existence of germs Invented Pasteurization

A New Scientific Theory Explains the Observations of Many Scientists Edward Jenner Smallpox Louis Pasteur Rabies and anthrax Robert Koch Tuberculosis and anthrax

Germ Theory of Disease Germs cause disease Predictions of the Germ Theory Many diseases are caused by germs Diptheria Whooping cough Measles Plague Modern medicine uses the Germ Theory to guide research

Ramifications of Germ Theory Previous concepts about the cause of many diseases incorrect Evil spirits Bad thoughts Excess blood

Theory vrs Scientific Theory Theory (as used outside of science) Guess Speculation Has not been tested

Scientific Theory Principle Tested many times Explains many different phenomena Makes predictions Falsifiable

Falsify Germ Theory Smallpox occurs without the smallpox virus Tuberculosis occurs without the TB bacterium Discovery of a different type of cause for infectious diseases Cell phones Computer screens Lack of exercise

Jeff’s Lost Dog Jeff’s beloved dog is missing (observation) Jeff thinks the dog has run away (hypothesis) What can falsify his hypothesis? Jeff finds his dog asleep in the house I love my dog

Testing Hypotheses Observation Experiment Jeff found his dog asleep in the house Scientists find the same bacterium in the bodies of people who die of the plague Experiment Jenner vaccinates boy with cowpox and later infects him with smallpox. The boy does not get smallpox.

100 Sick People Experimental group Control group 50 People 50 People Medicine X Control group 50 People Placebo

Three Days Later Experimental group Control group 34 Better 33 Better Medicine X Control group 33 Better Placebo

Three Days Later Experimental group Control group 34 Better 5 Better Medicine X Control group 5 Better Placebo

Why does this frog have extra legs? Website

Law vrs Theory Law Theory Observation that has been repeated numerous times Law of gravity Does not explain the observation Theory Explains why or how something in nature happens

Which is most important to a scientist? Fact Hypothesis Law Theory

Theory is the most important Explains laws, hypotheses and facts Law States what happens Hypothesis Untested theory Fact Observation

Major Scientific Theories Germ Theory of Disease Germs cause infectious disease Atomic Theory Matter is made if tiny atoms Gene Theory (Chromosomal Theory) Genes on chromosomes determine heredity Cell Theory All living things are made of cells

Theory of Evolution Populations of organisms change over time Changes result in new species that share a common ancestor.

Evolution is both a fact and a theory Evolution is documented in the fossil record and has been observed in our lifetime. Theory How evolution happens

Theory of Evolution Scientists no longer ask if evolution occurs. They study how evolution occurs. Evolution is the major theory that guides research in Zoology

Science A body of knowledge gained from studying the natural world It is tested against the natural world Does not use supernatural explanations Its conclusions are not absolute. New discoveries can revise previous conclusions It is falsifiable

The End