Evolution 2

Question 1

Hutton

Answer 1

Uniformitarianism theory. Earth is formed by slow forces that continuously shape the landscape.

Question 2

Lyell

Answer 2

Principles of Geology:
- Earth is changing by the same processes now as in the past
- Rocks are shaped by slow processes over time
- Earth must be over 10,000 years old

Question 3

cuvier

Answer 3

Studied mammoth and elephant fossils. Concluded they were different species–>Believed that species don’t change. Recognized extinction. Proposed catastrophism, when sudden events cause extinction followed by new species appearing.

Question 4

Lamarack

Answer 4

Species are not permanent. They change over time through adoption, use, and disuse. More used body parts develop. Inheritance of acquired traits. Traits developed during life and are passed to offspring. Organisms change for success in environments. Species become more complex over time. Unused parts disappear. Flawed theory: most acquired traits are not heritable. Many features don’t change because of usage.

Question 5

Darwin

Answer 5

observe species that vary globally, locally, and over time. Propose natural selection. Organisms with advantageous traits survive and reproduce. Species evolve over time from a common ancestor. descent with modification (his term for evolution.

Question 6

malthus

Answer 6

Noted that populations grow faster than resources which can lead to war, famine, and disease influence Darwin’s ideas. Struggle for existence is a key part of natural selection.

Question 7

What idea did Darwin’s studies lead to?

Answer 7

Species evolve over time through natural selection. Common ancestry explains similarities.

Question 8

Fossil records

Answer 8

Provide timeline, showing extinct species. Modern species resemble ancient ones.

Question 9

Geographic Distribution

Answer 9

Similar environments produce similar adaptations in species from different locations. Species with similar features may be distantly related.

Question 10

Molecular biology

Answer 10

Compares DNA/proteins. more similar equals a more closer relationship. For example, humans and chimps.

Question 11

Species vary locally.

Answer 11

Related species in different habitats in a local environment have different features.

Question 12

Species vary globally.

Answer 12

Distantly related species in similar environments in different parts of the world look and act similar.

Question 13

Hardy-Weinberg equilibrium requirements.

Answer 13

Random mating, no natural selection, no mutations, very large population, no moving in or out.

Question 14

If the Hardy-Weinberg equilibrium isn’t maintained, what does it lead to?

Answer 14

Constant microevolution.

Question 15

Directional natural selection.

Answer 15

Selects for one extreme against the other, white or black.

Question 16

Stabilizing natural selection.

Answer 16

Selects for the middle phenotype, gray.

Question 17

Disruptive natural selection.

Answer 17

Selects for both extremes, white and black.

Question 18

Sexual selection

Answer 18

Behaviors that attract mates, like mating dances or calls, bright colors, and strength. It causes certain traits to spread because they help an organism find a mate.

Question 19

Genetic drift

Answer 19

Change in gene pool by chance. Huge effects on small populations. Each generation has a shift in frequency of alleles based on which ones get passed to offspring.

Question 20

Founders Effect

Answer 20

Small group moves to new habitat. Some alleles lost to new population.

Question 21

Bottleneck effect.

Answer 21

Caused by natural disasters, few survive, some alleles are lost.

Question 22

Gene flow.

Answer 22

When population exchanges genes with a new group of individuals through interbreeding:
- Alters allele frequencies by adding new ones or changing existing ones.
- Random processes: Populations of a species often isolated by physical barriers.
- Reduces genetic diversity between populations.