1st Step: discover pattern and interconnections through observation
2nd Step: question the pattern and interconnections that are observed
• What - questions that describe patterns or relationships “What part of the tree does each bird species occupy?”
• How - questions whether there are causes of these patterns and relationships (proximal)
“How does each bird species select a particular part of the tree?”
• Why - questions why a system functions the way it does; examines the evolutionary basis of the patterns and relationships (ultimate)
“Why do bird species select different parts of the tree?”
• 3rd Step: develop possible answers to questions and express ideas about how a system works
- Hypothesis
• a prediction that can be tested
• declarative sentence
• reject or not reject (never accept)
- Null Hypothesis - no change or relationship
- Alternate Hypothesis - prediction of change or relationship
Ho: bird species are not distributed according to their preferred prey type
HA: bird species are distributed according to their preferred prey type
• 4th Step: evaluate hypothesis to determine if it is correct
• Sampling/Observational Studies:
- Descriptive studies
- Collect some measurable features of the natural world
• features = Variables
1 - observe & count the # of each insect (prey) type ingested
2 - sample insect (prey) distribution
“Natural Experiment” = unmanipulated over the tree
• Species A selected a particular insect species ... but this insect was found over the entire tree Ho is correct
Problem: do not establish cause-effect relationships
• Experimental Studies
- natural processes are allowed to proceed under conditions that are controlled (or manipulated)
• Experimenter must fully understand the natural history of the organism under study
• Mathematical Modeling
• Examine the fit of natural processes to mathematical relationships
• high variation in nature
- mathematical models are representations of nature
- relationships may be generally but not exactly true
- Models have heuristic value - may reveal unexpected patterns - or serve as a guide to new discoveries!
Does the model represent the essence of the relationship?
• 5th Step: draw inferences about ecological processes
- High variation in nature = high uncertainty in results
• Statistics = study and analysis of quantitative data
- rely on statistics to provide levels of certainty (or uncertainty) Without quantifying the level of uncertainty - results are meaningless
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