Biology and You Chapter 1 Pages 1 - 21

Nature of Science Chapter 1 Sections 1.1- 1.4 Written Homework: Do Check & Challenge on Page 4

What is Science? Science tries to understand the natural world by explaining how and why things are as they are.

Scientific Method Scientific Method - the organized approach used by scientists to solve problems and acquire information.

Steps of Scientific Method Problem Observations Hypothesis Experimentation Conclusion

Problem a question about natural world defines specific area to study

Observation thorough search for information examine others work in the area of interest collect data from experiments look for patterns

Hypothesis identify pattern form possible explanation for observations educated guess to explain able to predict new patterns If ………then……

Experiment tests hypothesis at least two groups: Experimental Group Control Group

Experimental Group has the independent variable which will causes an observable difference (effect) in the dependent variable If independent variable then dependent variable

Control Group identical to the experimental group except: it does not contain the independent variable is used for comparison to verify the affect of the variable

Conclusion if experiment verifies hypothesis report results publish report so others can repeat experiment to verify work

Conclusion if experiment does not verify the hypothesis: reformulate hypothesis or redesign experiment

Theory explanation for many different observations explanation supported by repeated experimental evidence

Law describes one observation is always true does not explain how or why

Lamarckian and Darwinian Theories of Evolution

Slow change with time Evolution Geological Evolution – slow change of Earth over time Organic Evolution – change of life over time

Fossil organisms were different from living organisms Theory of Evolution Fossil organisms were different from living organisms Organisms of past gave rise to current organisms

Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck French biologist Proposed first hypothesis of how evolution worked TWO (2) Laws: Law of Use and Disuse Law of the Inheritance of Acquired Traits

Law of Use and Disuse Change in environment forms barrier to survival organism needs to change to survive Use body part to over come barrier; part becomes bigger Doesn’t use body part to over come barrier; part becomes smaller.

Law of Inheritance of Acquired Traits Acquired Traits – the changes achieved during lifetime from use and disuse can be passed on to offspring

Validity? Use and Disuse seems true Practice makes perfect Inheritance of Acquired Traits not true Weismann experiment with mice Doberman dogs in textbook

Charles Lyell Geologist Forces today same as those in past Time forces working cause changes on earth’s surfaces Influences Charles Darwin

Charles Darwin HMS Beagle Galapagos Islands Diversity impressive Gentleman farmer Pigeon breeder

Theory of Natural Selection Overproduction – more produced than survive Competition – struggle for limited resource Variations – individual differences Adaptations – differences that favor success Nature “chooses” variations that become adaptations – “natural selection”

Scientific Attitude

Scientific Perspective Observation & Experiments Repeatable & Verifiable Refutable Natural world can be investigated and explained

Pseudoscience “false” science because research does not meet rigid criteria accepted by science Creationism Astrology Miracle diets and cures