Transcript The Nature of Science

The Nature of Science
Science asks three basic question:
1. What’s there?
2. How does it work?
3. How did it come to be this way?
Principle of Science
• Seeks to explain the natural world.
• Assumes that this is possible by gathering
evidence about it.
Science is a Process
• Ideas are developed through
reasoning and experiments.
• Scientific claims are based on
testing explanations against
observations of the natural
world and rejecting the ones
that fail the test.
• Subject to peer review and
replication.
• Scientific conclusions are well supported by facts
and are tentative only in the sense that all ideas
are open to scrutiny
• Science is not democratic: ideas are
accepted/rejected based on evidence not what
people think
• Science is non-dogmatic. In science things are not
accepted on faith but on evidence.
• Science cannot make moral or aesthetic
decisions.
Science corrects itself.
• Theories are central to scientific thinking:
Theory
- Popular meaning: a guess
- In science: a well-substantiated explanation of
events observed in the natural world
Fact
– A natural phenomenon repeatedly confirmed by
observation.
Law
– A description of how a natural phenomenon will
occur under certain circumstances.
Evolution
– Darwin defined this term as "descent with
modification.”
• biological evolution is the process of change by which
new species develop from preexisting species over time
• in genetic terms, evolution can be defined as any
change in the frequency of alleles in populations of
organisms from generation to generation.
“You’ve gotta grow big enough and strong
enough to reproduce.”
Misconception: “Evolution is a theory
about the origin of life.”
• Evolution deals with how life changed after its
origin.
Misconception: “Evolution is like a
climb up a ladder of progress;
organisms are always getting better.”
• “good enough” is just that – there is no
“perfect” organism, your ability to survive will
vary with environment
Misconception: “Evolution means
that life changed ‘by chance.’ ”
• Mutations are random, natural selection is
not.
Misconception: “Natural selection
involves organisms ‘trying’ to adapt.”
• Natural selection is based on variation within
a population and selection, not trying.
Misconception: “Natural selection
gives organisms what they ‘need.’ ”
• Natural selection has no intent.
• Evolution in action…