Natural Selection and Fitness

Natural Selection & Fitness

Basics

Highlights

• Variations are differences between organisms

• Fitness is the ability to survive long enough to reproduce and have offspring that will survive.

• Adaptations are characteristics that improve the ability to survive and reproduce

• Over time in a population, genes and characteristics that make a species more fit for the environment will occur more often in the population

• Environmental stresses (predators, food sources, etc.) select for the characteristics that improve fitness which is Natural Selection

• Natural selection can drive evolution

• Evolution is changes in populations over time

Multiple Choice

What variation in the frogs improved their fitness in the scenario given in the video? Why did it?

• Longer legs, jump farther

• Bigger eyes, see predators coming

• Body Color, blend in with environment

• No croaking sound, will not be heard by predators

Multiple Select

Which 2 are required to be fit for a specific environment?

• Ability to Survive

• Ability to reproduce and have offspring

• Ability to capture more sunlight

• Ability to reach food high in trees

Multiple Choice

Traits and genes that are more fit for the environment will..

• Increase in frequency

• Decrease in frequency

• Have a dangerous mutation for an organism

• Have no effect on the offspring

Multiple Select

What are 2 processes that cause variation in a species?

• Mutations

• Crossing Over

• Spermiogenesis

• Translation

Multiple Choice

An adaptation is an advantageous characteristic that ...

• improves the ability to survive and have offspring (reproduce)

• is a skill that is acquired through experiences

• is a talent that the organism has perfected through their life-span

Multiple Choice

Can an individual organism choose what adaptions they have?

• Yes

• No

Multiple Choice

Evolution is

• changes in an individual

• changes in a population over time

• a static environment in an individual

• a population that is in stasis

Multiple Choice

Sea turtles can lay anywhere from 70 to 190 eggs at a time. What does this over-reproduction ensure?

• There will be competition for resources

• Some offspring will survive long enough to reproduce

• That all the offspring will be the same

Multiple Choice

Suppose a certain species of insect lives in the lush green canopy of the rain forest. Some of the insects are bright green in color, and some are bright yellow. Assume there is a natural predator of the insect in the area. What do you expect to happen to the populations of the green and the yellow insects over time?

• The green insect population will increase and the yellow insect population will decrease.

• The green insect population will decrease and the yellow insect population will increase.

• Both insect populations will remain constant over time.

• Both insect populations will increase over time.

Multiple Choice

What is the most likely explanation of the data shown below? (click the picture)

• There has been a drought in the area that is affecting all life forms.

• The population of natural predators of the moths has gotten smaller.

• The moths are living in an environment with light trees.

• The moths are living in an environment with dark trees.

Multiple Choice

Why is the mouse population changing over time? (click the picture)

• The light mice can reproduce more successfully than the dark mice

• The hawks eat more dark mice than light mice because the dark mice taste better

• The hawks eat more light mice than dark mice because they can see the light mice more easily

• The hawks eat more dark mice than light mice because they can see the dark mice more easily

Multiple Choice

Why are advantageous traits more likely to be passed onto offspring?

• Because they are more likely to survive and reproduce.

• Because they come from dominant alleles.

• Because they come from recessive alleles.

• Because the trait is an acquired phenotype.