Ecology and Evolution of Dispersal

Question 1

What is dispersal?

Answer 1

The movement of animals between habitat patches to increase their chances of survival. Includes geneflow, the exchange of genetic variation across space.

Question 2

What are the reasons why an animal may disperse?

Answer 2

Avoid competition
Locate scarce resources
Avoid predation
Find mates
Avoid inbreeding

Question 3

What are the benefits of dispersal at the individual level?

Answer 3

Less competition
More resources
Less predation
More mates
Less inbreeding

However, the reverse may be true when an animal disperses, as they may find less of the benefits associated with dispersal.

Question 4

What are the benefits of dispersal at the population level?

Answer 4

Genetic variation
Spatial structure
Metapopulation resistance
Range dynamics

Question 5

What is a metapopulation and why are they important?

Answer 5

A metapopulation is a group of connected populations that allow other patches to be colonised and encourages geneflow. Important in terms of conservation as they can lower a species’ extinction risk. When habitats are fragmented, metapopulations can be split into sub-populations, raising extinction risk.

Question 6

Can dispersal be inhertied?

Answer 6

Mean heritability of behaviours is 0.23, dispersal is 0.35. Very complex trait and likely to be polygenic, however some genes have a very profound impact on controlling dispersal.

Question 7

Describe eco-evolutionary dynamics

Answer 7

Animals originate from a larger population and will disperse a short distance from this population. As time goes on and more generations disperse, the distance they travel increases.