Context Dependent Outcome
Amanda Acton
Biology 4800
What is Context Dependent Outcome?
• Outcomes that occur as a result of
interactions between species depend on the
context in which they occur.
• It can be misleading to study any interactions
between species without also looking at
environmental differences
• Examples
Benefits of parasitic infection: a test
using a ground squirrel – trypanosome
system
• Why replicate the experiment performed in
1971 by Lincicome?
• What are the main objectives of the
experiment?
The Experiment
• 140 Richardson’s ground squirrels captured
• Each tested for trypanosome infection 3 times,
with 37 testing negative all times being used in
the experiment as controls
• Half the squirrels were given diets containing
pyridoxine, and the other half given diets
deficient in pyridoxine
• Half of each of these groups were restricted to
how much food they could consume daily (~85%
body mass), where the rest could consume food
as they pleased
Results
• Trypanosomes had higher intensity on
squirrels that got the complete diet
• The ad libitum diet deficient in pyridoxine
was the only treatment that showed
significant effect on mass gain
Conclusions
• Some reasons why trypanosomes may have
positive effects on the pyridoxine-deficient
squirrels
• Predator avoidance
• Reproduction
• Survival through hibernation
• How this shows context dependent outcome?