I SSUES IN B IOLOGY & T HE S CIENTIFIC M ETHOD Packet #1

B IOTERRORISM

The use of biochemical agents for terrorist purposes. Pathogens Anthrax Bacillus anthracis Smallpox Variola major Agriculture pesticides Biowarfare Use of disease-producing microorganisms or biocides to cause death or injury to humans, animals and/or plants

A VIAN FLU PANDEMIC

Refers to influenza A viruses found chiefly in birds Some infections, caused by the virus, can be carried over to the human population Hong Kong 1997 Virginia 2002 New York 2003 Vietnam 2005 Iraq

E MBRYONIC S TEM C ELLS Ability to develop in different cell types Treat diseases, conditions and disabilities v/index.asp

O VER POPULATION Condition of any organism’s numbers exceeding the carrying capacity of its ecological niche. How does this relate to humans? m/over%20population

E MERGENT D ISEASES

G LOBAL W ARMING Increase in earth’s average temperature and the climatic impacts that it may have.

B IODIVERSITY Biodiversity – The variability among living organisms on the earth, including the variability within and between species and within and between ecosystems. A goal of scientists is to discover the effects of the previously mentioned not only on humans, but the estimated 7 – 20 million species on earth. How do we do that?

S CIENTIFIC M ETHOD Manner for investigating nature Scientists attempt to construct an accurate, reliable, consistent and non-biased representation of the natural world Few scientists adhere to the “strict procedures” Creativity, individuality, distinct

S CIENTIFIC M ETHOD Scientific Theories 2 components Describes the patterns seen in the natural world Identifies a process or mechanism responsible for a pattern Scientific Method (Biology) A study of patterns of living things and their processes

S CIENTIFIC M ETHOD C OMMON S TEPS Observation An observation is made regarding some event or characteristic of the world A problem is developed An open-ended question that cannot be answered by a yes or no answer Forming a Hypothesis Postulating a premise An explanation of the phenomena observed Predict the existence of other phenomena or predict quantitatively the results of new observations Involves critical thinking and critical analysis Deductive reasoning Reasoning from a general observation to a specific conclusion Inductive reasoning reasoning from a specific case to the general Hypothetico Reasoning

S CIENTIFIC M ETHOD C OMMON S TEPS Experiment Testing the hypothesis Experimental Predications States results that may be expected from observations and/or from experimental tests Experimental Design Experience; creativity; sense of what is practical Methods and procedures Adaptable Able to reexamine as new information is collected Suppose to test a premise Best when designed to “disprove” a hypothesis Often said in science that theories can never be proved but only disproved A hypothesis can never be proven but evidence, collected during experimentation, can be used to support

E XPERIMENT II Purpose of an Experiment Disprove a hypothesis Evaluate an alternate hypothesis Null hypothesis Unbiased Variables must be defined Dependent Variables Measureable and observable things Independent variable Should be only one during an experiment Can be manipulated and changed Controlled variables Kept constant and not allowed to change *Control All experiments should have one Used as standard f comparison

S CIENTIFIC M ETHOD C OMMON S TEPS Collection of Results & Interpretation of Data Must use same criteria (technique) for collecting all data Tables; graphs to represent data Statistical Analysis T-test Compares the means of two groups ANOVA Compares the means of three or more groups Chi Square Compares how closely the observed data is to the expected results *Experimenters should also look at the variance

ANOVA

S CIENTIFIC M ETHOD C OMMON S TEPS Conclusion Does the experiment match your predictions? Is your hypothesis supported Does your results agree with other findings? Replicate the experiment

S CIENTIFIC M ETHOD

T HEORY /L AW Hypothesis whose predictions have stood up to thorough and rigorous testing with experiments and observations.

L IMITATIONS OF THE S CIENTIFIC M ETHOD Some hypotheses are not experimental Intelligent beings in the universe Global warming *Theory of evolution