Lecture Two - Ecology II

Question 1

What are the four different types of ecology?

Answer 1

Question 2

Describe the four steps of evolution - ecology as the engine driving evolution.

Answer 2

1) Variation in a population. Some of these variations are heritable.
2) individuals can be so fucund that they can rapidly produce more offspring than can possibly survive.
3) Different undividuals can leave different numbers of descendents (differential success).
4) The number of descendents depends on the interaction of the environment with the characteristics of the individual - natural selection.

Question 3

What is the heritability equation?

Answer 3

h^2 = V genetic / (V genetic + V environment)

Where h^2 is heretability and V is varience in trait

Question 4

What is the definition for heritability?

Answer 4

The transmission of a characteristic from parent to offspring.

Question 5

What are the different types of selection?

Answer 5

Stabilizing selection:

Phenotypes near the mean are more favourable than those at the extremes.

Diractional selection:

Phenotypes at one extreme are selected for and phenotypes at the other extreme are selected against.

Disruptive selection (very rare):

Individuals in the middle are selected against, thus two different means/modes are formed.

Question 6

Define coevolution.

Answer 6

The influence of closely ralated species on one another in their evolution.

Question 7

Draw the table for species interactions.

Answer 7

Question 8

Define parasitism and its subcatagories.

Answer 8

Parasitism: One organism that derives its nourishment from another. (Rarely kill the host).

Endoparasitism: live within the body of the host. E.g. tape worm.

Ectoparasitism: live outside the body of the host. E.g. Ticks and lice. (Rarely kill the host).

Parasitoides: Usually insects, closely slighned symbiosis with a specific host, who it ultimatly kills.

Question 9

Define resource partitioning and character displacement, and describe their relationship.

Answer 9

Resource partitioning: Natural selection drives competing species into different patterns of resource use or different niches. This means that they can coexist.

Character displacement: Occurs when two similar species coexist. Through natural selection, the more different an individual is to the neighbouring species, the more highly it is selected for, thus the species evolve to be more different from one another while living in symparty.

Character displacement occurs due to resource partitioning and reduces competition.