7.2 Natural selection and Artificial selection

What is Natural selection?

The process of characteristics of a population of organisms change over many generations

What is selective pressure?

Environmental conditions or other organisms that choose traits for organisms (Soot covered trees and predators)

What is Fitness?

The relative contribution an individual makes to the gene pool by producing offspring that survive long enough to reproduce (more fit if they are able to contribute to the gene pool)

What do you need for natural selection to occur?

You not only need selection pressure, you also need genetic variation (diversity)

What would happen if there was no genetic diversity?

Extinction

Why is maintainting high genetic variation in a population essential for long term survival?

Since no one can predict how the environment might change in the future (which trait might be important for the future)

What is artificial selection?

selective pressure exerted by humans on populations in order to improve or modify particular traits

What are consequences of artificial selection?

Leads to a loss of genetic diversity

What is monoculture?

the production of a single crop in a large area

What is a disadvantage of monoculture?

A disease can wipe out the entire species