- Who: biologists David Reznick (UC-Riverside) and John Endler (UC-Santa Barbara).
- What: Studied several populations of guppies (Poecilia reticulata).
- Where: Small pools in streams in Trinidad.
- Populations are isolated, some by small waterfalls.
- Populations in different streams had differences in life histories.
Their observations raised two questions:
- Are differences in guppy population life histories due to physical environment?
- Are differences in guppy population life histories due to feeding preferences of the predators?
Design an experiment to answer one of those questions.