4.1.5 - Natural Selection

Question 1

What Is Variation?

Answer 1

The differences between individuals in a species population.

Question 2

What Are The 2 Types Of Variation?

Answer 2

~ Intraspecific variation.

~ Interspecific variation.

Question 3

What Is Interspecific Variation?

Answer 3

Between different species.

Question 4

What Is Intraspecific Variation?

Answer 4

Between individuals of the same species.

Question 5

What Causes Variation Within A Species Population?
(2 Points)

Answer 5

~ Random mutations, which introduce new alleles into a population.

~ Meaning some individuals within the population possess different phenotypes showing variation.

Question 6

What Are Selection Pressures?

Answer 6

Environmental factors that affect an organisms chance of survival.

Question 7

What Are Examples Of Selection Pressures?
(3 Points)

Answer 7

~ Predation.

~ Diseases.

~ Competition.

Question 8

How Do Selection Pressures Affect Individuals In A Population?

Answer 8

They create a struggle for survival.

Question 9

What Happens To The Individuals Without The Advantageous Alleles?

Answer 9

They don’t survive, meaning there is fewer individuals and less competition for resources.

Question 10

What Happens To The Individuals Which Do Possess The Advantageous Alleles?

Answer 10

Survive and pass on their advantageous alleles to their offspring.

Question 11

How Do Selection Pressures Over Several Generations Affect Allele Frequency?

Answer 11

They alter the frequency of alleles through natural selection.

Question 12

What Is Natural Selection?

Answer 12

Process by which individuals with a favourable phenotype are more likely to survive and pass on their alleles to offspring.

Question 13

What Happens To The Frequency Of Advantageous Alleles Over Time?

Answer 13

It increases over generations.

Question 14

How Does the Frequency Of Non-Advantageous Alleles Change Over Time?

Answer 14

It decreases in the population.

Question 15

What Do Changes In Allele Frequency Ultimately Lead To?

Answer 15

Evolution within the population as the favourable adaptations become more common.

Question 16

Who Came Up With Theory Of Evolution By Natural Selection?

Answer 16

Charles Darwin.

Question 17

What Does Evidence Provide In Scientific Theories?

Answer 17

Confidence.

Question 18

Describe How Peppered Moths Provide Evidence For The Theory Of Evolution
(8 Points)

Answer 18

~ Peppered moths show variation in colour, either light or dark, dark is caused by mutations.

~ Pre 1800s, there were more light-coloured moths.

~ During the 1800s, industrial pollution darkened many trees.

~ Dark-coloured moths became better camouflaged in this environment, helping them hide from predators.

~ Light-coloured moths stood out against the dark trees and were more likely to be eaten by predators.

~ Dark-coloured moths faced less competition for resources like food and mates.

~ Dark-coloured moths were more likely to survive and pass their dark colour allele to their offspring.

~ Over time, the population of dark-coloured moths increased.