Evolution Main Ideas

Question 1

List and describe first principle of natural selection

Answer 1

1. Overproduction - species will have a lot of offspring to ensure survival of species

Question 2

List and describe second principle of natural selection

Answer 2

2. Variation - these offspring will have a variety of traits

Question 3

List and describe the third principle of natural selection

Answer 3

3. Competition - resources are typically limited and some traits are better suited to their environment.

Question 4

List and describe the fourth principles of natural selection

Answer 4

4. Adaptation - The better traits allow for better survival and reproduction

Question 5

List and describe the fifth principle of natural selection

Answer 5

5. Decent with modification - well-adapted individuals will pass down their beneficial traits. Over generations the population experiences a genetic change

Question 6

What is the difference between natural selection and artificial selection?

Answer 6

Natural selection is driven by the forces of nature and always results in individuals that are better suited to the environment. Artificial selection is driven by humans selection for desired trait which does not always lineup adapted individuals.

Question 7

Example of natural selection

Answer 7

Light-colored moths blend in with lichen-covered trees, while dark-colored moths blend in with trees without lichen. In environments with more lichen, there are more light-colored moths than dark.

Question 8

Example of artificial selection

Answer 8

All dog breeds we have today were bred originally from wolves by humans selecting from various traits (ex. Looks, friendliness, protectiveness, sense of smell, Etc.)

Question 9

Bell curve distribution

Answer 9

Traits within a population typically occur at a normal or a bell curve distribution

Question 10

Directional selection

Answer 10

Directional selection occurs when one extreme of a trait is favored

Question 11

Stabilizing selection

Answer 11

Stabilizing selection occurs when the average trait is favored within a population

Question 12

Disruptive selection

Answer 12

Disruptive selection occurs when both extremes of a trait are favored

Question 13

Fossil record (evidence of evolution 1)

Answer 13

The fossil record shows slow, evolutionary change of organisms throughout millennia - how they lived compared to others

Question 14

Embryology ( evidence of evolution 2)

Answer 14

Similar features of embryos of very different organisms. Suggest a common ancestor

Question 15

Anatomical record (evidence of evolution 3)

Answer 15

• Homologous structures -> similar anatomy, different functions. Suggest a common ancestor
• Analogous structures -> different anatomy, same function. Suggest common evolutionary pressures on unique organisms
• Vestigial structures -> relics from earlier common ancestors. Suggests similar evidence as the fossil record. Showing the process of evolution itself.

Question 16

Molecular biology ( evidence of evolution 4)

Answer 16

All living things have DNA.

• MOST living things share MOST of their DNA with other living things
• More shared amino acid sequences = most recent common ancestor.

Question 17

Example of fossil record

Answer 17

Fossils of the same prehistoric organism demonstrating different characteristics and traits when in different time periods

Question 18

Example of embryology

Answer 18

Early stages of fish, salamander, tortoises, chickens, and humans all begin looking very similar. It’s not until further in development that they start to show different features and traits; suggest common ancestor

Question 19

Example of homologous structures

Answer 19

Human limb compared to a whale fin

Question 20

Example of analogous structure

Answer 20

Butterfly wing compared to a bird wing

Question 21

Example of a Vestigial structure

Answer 21

Wisdom teeth, appendix, muscles for moving ear, body hair in humans

Question 22

Example of molecular biology

Answer 22

Humans differ in only 1 amino acid with monkeys

We also only differ in 4 amino acids with rabbits

Question 23

Which is the best to explain evolution?

Answer 23

Anatomical record?

Question 24

Directional selection example in terms of mice

Answer 24

One color of mice had a better survival rate in the environment so the population started to switch

Question 25

Disruptive selection example in terms of mice

Answer 25

One color was extremely favored in comparison to the other
White > Dark
Dark > White

Question 26

Stabilizing selection example in terms of mice

Answer 26

Neither extreme of color was favored in population
White = Dark
Dark = White
(Somewhat)