Natural selection

Question 1

Define selection pressures

Answer 1

Environmental factors that limit a population of a species.

Question 2

What are the 3 primary selections pressures we should know?

Answer 2

Predation
Disease
Competition

Question 3

What factors aids the process of evolution via natural selection?

Answer 3

There is a genetic variety within the populations of all species
If number of offspring produced by parent cannot be supported with the resources available
Variety of phenotypes that selection operates against

Question 4

Why is evolving to overproduce offspring beneficial?

Answer 4

Reduction in death rates from predators, competition, disease, temp extremes and natural disasters

Question 5

How can an organism with a low reproductive rate help to reduce death rates?

Answer 5

Provide high parental care to the offspring

Question 6

What is the issue with overproduction of offspring?

Answer 6

May cause intraspecific competition.
This in turn will cause a selection pressure as offspring more adapted to low resource environment will survive and reproduce.

Question 7

What is the benefit to having variation in a population?

Answer 7

In a change of environment, there is a greater likelyhood of an organism having a combination of alleles advantageous to the struggle
This allows organism to survive and reproduce to pass on allele combination to future generations to adapt to environmental change

Question 8

Process of evolution via natural selection

Answer 8

There’s a variety of phenotypes within a population.
An environmental change occurs and as a result of that the selection pressure changes.
Some individuals possess advantageous alleles which give them a selective advantage and allow them to survive and reproduce.
The advantageous alleles are passed on to their offspring.
Over time, the frequency of alleles in a population changes and this leads to evolution