Transcript Chapter 1

Chapter 1
Science and Marine Biology
Karleskint
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Key Concepts
• Marine and terrestrial environments are
interrelated, interactive, and
interdependent.
• The ocean is an important source of
food and other resources for humans.
• Marine biology is the study of the sea’s
diverse inhabitants and their
relationships to each other and their
environment.
Key Concepts
• The history of marine biology is one of
changing perspectives that have shaped
the modern science and its applications.
• Marine laboratories play an important
role in education, conservation, and
biological research.
Key Concepts
• It is important to study marine biology
in order to make informed decisions
about how the oceans and their
resources should be used and managed.
• Scientists use an organized approach
called the scientific method to
investigate natural phenomena.
• We will discuss this further later.
Importance of the Oceans
and Marine Organisms
• World ocean covers
nearly 71% of earth’s
surface
• 99% of the Earth’s
biosphere (livable space)
is in the ocean
• Oceans interacting with
the atmosphere affect
weather patterns on a
global scale
Importance of the Oceans
and Marine Organisms
• Marine Organisms:
– provide substantial part of
human food supply
– Unfortunately, we have
overharvested these
resources
- are used as subjects of
scientific study for many areas
of research
- are useful to medicine and
industry providing jobs for many
people worldwide
Study of the Sea and Its Inhabitants
• Oceanography
– study of the oceans and their phenomena,
such as waves, currents and tides
• Marine biology
– study of the living organisms that inhabit
the seas and their interactions with each
other and their environment
• Knowledge of these disciplines will
promote marine conservation.
Marine Biology: A History of
Changing Perspectives
• Early studies of marine organisms
- traced back to ancient Greeks and Romans
- Aristotle and the “ladder of life”, a scheme of classification
• Renewed interest in marine organisms
– voyage of the HMS Beagle and Charles Darwin’s On the
Origin of Species, theory on evolution through natural
selection
– discovery of deep sea organisms on retrieved transatlantic
telegraph cable
– This was a cable that was placed across the Atlantic
for early communication (before the days of
satellites).
– When it was pulled up, deep sea organisms were
observed growing on it
Marine Biology: A History of
Changing Perspectives
• Beginnings of modern marine science
– Challenger expedition exploring world’s oceans
• Mid 19th century
• First voyage dedicated just to science exploration
» Before that, scientists were invited to join other
expeditions
• 4,700 new species collected and described
• Lots of specimens were collected – took 19 years to go
through the data
– funding of the first marine biology laboratory: Anderson
Summer School of Natural History, predecessor of the
Marine Biological Laboratory at Woods Hole
– forerunner of other U.S. marine laboratories
Marine Biology: A History of
Changing Perspectives
• Marine biology in the twentieth century
– Fridtjof Nansen’s Arctic expedition
– Sir Alistair Hardy’s Antarctic expedition
– impact of human activities on marine
environment gains attention
• More research funded to solve problems and to
determine human impacts
• Marine biology today
– deep-sea submersibles
– discovering ties between terrestrial and
marine environments
– information sharing via the Internet
Process of Science
• Hypothesis
• explanations that can be tested by
experiments
• Has to be testable
• Not just an “educated guess”
• Scientific method – an orderly pattern
of gathering and analyzing information
Steps in the Scientific Method
• Making observations (Step 1)
• Form a hypothesis (Step 2)
• Design experiments (Step 3)
• experimental variable
• experimental set
• control set
– Experiment has to be repeated and reproducible
• Gather results (Step 4)
• Statistical analysis, are the results significant?
• Draw conclusions
• Support or reject the hypothesis
• Never “prove” a hypothesis – why?
• Inductive reasoning vs. deductive
reasoning
• Inductive reasoning – using individual
observations to come to general conclusion
» For example: tuna, shark, and sailfish all have gills.
Therefore, ALL fish must have gills.
• Deductive reasoning – using general principles to
come to specific conclusions
» For example: All fish that have been studied so far
have gills. Therefore, clownfish must have gills.
Steps in the Scientific Method
EXAMPLE:
• Plant growth in a salt marsh: a case
study of the scientific method
– observation of growth patterns and analysis
of soil samples
– experiment to test hypothesis
– analysis of results of the experiment
Process of Science
• Alternative methods of science
– experimentation is not always possible
– observational science – observation alone
must be used to support or deny the
hypothesis
• Scientific Theory
• The word “theory” is used differently in
everyday speech
• In biology, a theory is supported by years of
research, evidence, and is supported by the
scientific community.
– We do not have laws in biology – why not?