Scientific Method - Environment and Ecology - Lecture Slides, Slides of Ecology and Environment

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Scientific Method

Environment & Ecology

The nature of science

• Science :
  • A systematic process for learning about the world and testing our understanding of it
  • The accumulated body of knowledge that results from a dynamic process of observation, testing, and discovery
• Science is essential:
  • To sort fact from fiction
  • Develop solutions to the problems we face

Scientists test ideas

• Scientists examine how the world works by observing, measuring, and testing - Involves critical thinking and skepticism
• Observational (descriptive) science : scientists gather information about something not well known or that cannot be manipulated in experiments - Astronomy, paleontology, taxonomy, molecular biology
• Hypothesis-driven science : research that proceeds in a structured manner using experiments to test hypotheses through the scientific method

The scientific method

• Observations
• Question
• Formulate Hypothesis
• Conduct Experiment
• Analyze Results
• Conclusions
• Discussion

A technique for testing ideas

Experiments test the validity of a

hypothesis

• Manipulative experiments yield the strongest evidence - Provides the strongest type of evidence - Reveal causal relationships: changes in independent variables cause changes in dependent variables - But many things can’t be manipulated: long-term or large-scale questions (i.e., global climate change)
• Natural experiments show real-world complexity
  • Only feasible approach for ecosystem or planet-scale
  • Results are not so neat and clean, so answers aren’t simply black and white

Scientific Method: Example

Many habitats are fragmented. Corridors are being constructed between patches. Do they really work? Docsity.com

Butterflies will move into connected habitat patches more frequently than into unconnected habitat patches

Experiment results

Pisaster

Paine’s study on Pisaster and blue mussels

What effect does starfish removal have on community structure?

chiton (^) limpet

mussels (Mytilus)

barnacles

Keystone Species

Paine’s study on Pisaster and blue mussels

Mangrove Study

Do sponges affect mangrove root growth?

Select a large sample size

Randomly divide the sample into 2 groups

Treat the groups equally in all ways but one

Observe or make measurements

Compare results

Mangrove Study

QUESTION: Review

Which is the correct order of the scientific

method?

a) Observation, hypothesis, predictions, testing, results b) Hypothesis, observation, testing, predictions, results c) Observation, predictions, testing, results, hypothesis d) Predictions, observation, hypothesis, testing, results

QUESTION: Interpreting

Graphs and Data

What happens if test

results reject a

hypothesis?

a) The scientist formulates

a new hypothesis.

b) It shows the test failed.

c) The scientist should be

fired.

d) The scientist used faulty

data.