The Science of Biology

Chapter 1

•Latin scientia = knowledge

•Knowledge gathered through the process we now call “Science”

–Process used to discover the nature of the universe

Reasoning of Science

•Deductive – making individual decisions based on generally accepted principles (only as good as those principles)

•Inductive – discovering general principles based on careful examination of specific cases (based on interpretation of observations)

Language of Science

•Why does science have its own language?

•Specialization creates need for specific terms

–Found in all fields

Scientific Process

•Gathers evidence and provides the most logical explanations to observed phenomena

•Transparent

•Not flawless

•Should not be dogmatic

Assumption underlying Science

•Mechanism = the universe can be explained solely by physical and chemical laws (scientific process will work)

Alternatively

•Vitalism = supernatural forces at work along with physical and chemical laws (beyond the realm of science, untestable, unrepeatable)

How Science is Done

•Observation

•Hypothesis - Suggested explanation that accounts for observations.

–Must be testable

•Test of hypothesis - Experiment or extensive observation.

–Try to eliminate one or more competing hypotheses.

–Establish controls by holding all variables but one constant.

How Science is Done

•Predictions

–If…,then…

–Provide method of testing validity of hypothesis.

•After experiment

–Compare new data to hypothesis

–Revise hypothesis

Purpose/Limits of Science

•Gather best available evidence for explaining the nature of the universe

•Since new evidence is always being gathered, hypotheses and scientific theories are subject to constant revision

•Science never stands still

•Failure is part of scientific process

Conclusions of Scientific Method

•Can only “support” or “refute” hypotheses

•All sciences work with hypotheses at various levels of support

Scientific Method (cont.)

•Novel hypotheses and important observations or experiments supporting an hypothesis are published in scientific journals

–once extensive support for an hypothesis is published, it approaches “fact”

•The only thing better than developing a widely supported hypothesis is refuting one (causes vigorous testing by multiple scientists)

Scientific Method (cont.)

•Theory = mature, coherent body of interconnected statements based on evidence and logical reasoning explaining many observations

•Line between hypothesis and theory often blurry

•Both are subject to constant revision with the addition of new data, analyses, and interpretations

Scientific Method (cont.)

•While scientific method isn’t perfect, it works pretty well

–Virtually all advances in medicine, engineering, agriculture, etc. are the result of the scientific method

–Fields once dominated by supernatural explanations of observed phenomena

–Most importantly, methodology of science is transparent

•Repeatable & testable

Science of Biology

•Greek “bios” = life, “logi” = study

•The science of life and of living organisms, including their structure, function, growth, origin, evolution, and distribution. It includes botany and zoology and all their subdivisions.

Properties of Life

•Basic Characteristics

–Order/organization (subatomic particles – biosphere)

–Sensitivity (response to stimulus)

–Growth, Development, and Reproduction

•Production of next generation

–Energy utilization (metabolism)

–Evolutionary adaptation (genetic response to environment)

–Homeostasis (relatively stable internally)