Trinidad guppies Flashcards
What can species interactions lead to?
Evolutionary and ecological change.
What are the different guppies in Trinidad?
High predation life history: Live fast and die young. More offspring. Smaller. Predators are likely to cause death. Low predation life history: Live slow and die old. Fewer offspring. Bigger. Starvation or disease are likely to cause death.
What are the approaches to guppy research?
- Observations in natural streams
- Experimental seeding of streams where guppies don’t originally live
- Mesocosm experiments (artificial streams where the fish community structure and population sizes can be manipulated)
- Labatory experiments
- Mark recapture method
- Record where in the stream they were captured
High vs Low predation guppies in terms of their characteristics?
Why is there such a big difference between the two types of guppy?
When living at high densities in low predation, lose the ability to live with predators, such as being able to swim quickly.
When living in high predation, lots of food around so can develop very quickly as there are fewer guppies around. Grow slowly when there are no predators as less food. Populations are biased towards younger guppies as there is enough food to reproduce lots.
Are the changes in guppies genetic or purely due to environment?
Take fish from low and high predation streams. Grow both in the lab, so differences must be genetic. Differences are genetic.
Low predation guppies always evolve from high predation guppies when released from predation. Selection always pushes populations to the highest fitness in terms of combinations of genes (adaptive landscape).
Shows that species interactions can lead to both ecological and evolutionary responses
Define eco-evolutionary dynamics?
Ecological and evolutionary change that occurs simultaneously.
Can Lotka Volterra model be applied to real life situations?
Normally no, as real world is much more complicated.
