Natural Selection & Fitness

Natural Selection & Fitness

Natural Selection

• 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

Misconceptions (False Statements)

THE ORGANISM TRIES TO ADAPT TO ITS SURROUNDINGS, ENVIRONMENT.

EVOLUTION: ORGANISMS ARE ALWAYS GETTING BETTER "MORE FIT" AS TIME PASSES

Multiple Select

SELECT ALL FALSE STATEMENTS OF NATURAL SELECTION.

IN OTHER WORDS: WHAT IS NOT NATURAL SELECTION.

• BIG AND STRONG ALWAYS DOMINANT

• THE BETTER TRAITS FOR THE ENVIRONMENT WILL SURVIVE AND REPRODUCE

• BLENDING OR CROSS BREEDING DIFFERENT SPECIES TO PRODUCE NEW FORMS

• ALL ORGANISMS EVOLVE DURING THEIR LIFETIME.

• NATURE SELECTS WHO WILL THRIVE (SURVIVE) IN THE ENVIRONMENT

Multiple Select

Which two 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 a dangerous mutation for an organism

Multiple Select

What are 2 processes that cause variation in a species?

• Mutations

• Spermiogenesis

• Crossing Over

• Translation

Open Ended

Would a white tiger survive in the wild? Explain why or why not using the following terms:

camouflage, natural selection, starvation, reproduce

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

Finches in Galapagos Islands

• Darwin observed how the different finches had different beaks and different food sources for each island in the Galapagos .

Multiple Choice

What is the advantage of having different shaped beaks?

• To look different from other species.

• To be able to eat the food readily available in the environment.

• To protect itself against predators.

• To protect itself against prey.

Multiple Choice

Darwin observed several different types of finches. Why are there so many different types?

• Finches live in different places, but eat the same food.

• Finches live in the same place, but eat different types of food.

• Finches live in different habitats and eat different types of food.

• Finches are found all over the world.

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

Bacteria

Antibiotic Resistance

Antibiotic Resistance

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.

Selective Pressure

• Directional Selection - one of the extreme traits is selected for

• Disruptive Selection - both of the extreme traits are selected for

• Stabilizing Selection - the moderate trait is selected for

Multiple Choice

Individuals with intermediate traits are more likely to survive and reproduce

• stabilizing selection

• directional selection

• adaptive radiation

• disruptive selection

Multiple Choice

On average, human newborns weigh 7.2 pounds.

• directional selection

• stabilizing selection

• disruptive selection

• artificial selection

Multiple Choice

the selection pressure favors the extreme phenotypes, dividing the population into 2 distinct groups

• directional selection

• stabilizing selection

• geographic selection

• disruptive selection

Multiple Choice

snails with a forward spiral and snails with a backward spiral have an advantage in their environment

• directional selection

• stabilizing selection

• disruptive selection

• artificial selection

Multiple Choice

individuals with alleles for an extreme type are more likely to survive and reproduce

• stabilizing selection

• directional selection

• disruptive selection

• genetic drift

Multiple Choice

Aspen trees that are over 25 m tend to blow over in high winds; aspen that are under 15 m don't get enough sun

• directional selection

• stabilizing selection

• disruptive selection

• artificial selection

• sexual selection