ISSUES IN BIOLOGY & THE SCIENTIFIC METHODPacket #1

BIOTERRORISM

BIOTERRORISM

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

AVIAN FLU PANDEMIC

AVIAN 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 2006 http://www.cdc.gov/flu/avian/gen-info/avian-flu-humans

.htm

EMBRYONIC STEM CELLS

Ability to develop in different cell types

Treat diseases, conditions and disabilities

http://stemcells.nih.gov/index.asp

OVER POPULATION

Condition of any organism’s numbers exceeding the carrying capacity of its ecological niche.

How does this relate to humans?

http://www.answers.com/over%20population

EMERGENT DISEASES

http://www.cdc.gov/ncidod/id_links.htm

GLOBAL WARMING

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

BIODIVERSITY

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?

SCIENTIFIC METHOD

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

SCIENTIFIC METHOD

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

SCIENTIFIC METHODCOMMON STEPS 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

SCIENTIFIC METHODCOMMON STEPS 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

EXPERIMENT 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

SCIENTIFIC METHODCOMMON STEPS

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

SCIENTIFIC METHODCOMMON STEPS

Conclusion Does the experiment match your predictions? Is your hypothesis supported Does your results agree with other findings?

Replicate the experiment

SCIENTIFIC METHOD

THEORY/LAW

Hypothesis whose predictions have stood up to thorough and rigorous testing with experiments and observations.

LIMITATIONS OF THE SCIENTIFIC METHOD

Some hypotheses are not experimental Intelligent beings in the universe Global warming *Theory of evolution