Lecture 4- Chapter 6:

Question 1

Georges Cuvier

Answer 1

• came before Darwin
• discovered extinction in 1813
• extinction was a wild notion

Question 2

Carl

Answer 2

• father of taxonomy
• made thousands of species
• coined the term homosapiens
• christian
• believed he was doing God’s work

Question 3

Charles Darwin

Answer 3

• 1859: The Origin of Species
• used the phrase “descent with modification”
• natural selection (ex in book include hunting of bog horn sheep and cod fisheries)

Question 4

What is Evolution (3 points)

Answer 4

1. Descent with Modification
2. Allele Frequency Change
3. Populations evolve, individuals do not

Question 5

Descent with Modification

Answer 5

• Fossils: show descent with modification (In terms of teeth and limbs)
• Species do change
• Ex: stickleback fish, horses, and dinosaurs being extinct

Question 6

Allele Frequency Change

Answer 6

-allele frequency changes within a population
-Populations of organisms we do see variation within them
-If there is strong selection on a population, we will see genotype changes
- Ex. Arizona desert white sand mostly certain mice want to be cryptic from their predators so they are less visible than other mice within the population

Question 7

Ecology Definition

Answer 7

• the interaction between organisms

Question 8

Populations Evolve, Individuals Do Not

Answer 8

• evolution never follows over evolutionary time

Question 9

What are the Mechanisms of Evolution

Answer 9

1. Mutation
2. Natural Selection
3. Genetic Drift
4. Gene Flow

Question 10

Mechanism of Evolution 1. Mutation

Answer 10

-Individuals in populations differ in their phenotypes
-Different alleles arise by mutation
-Ex. Elephants utilize their tusks for manipulating their ecology
-Recently, poaching has been very popular in places where they live
-To get their tusks, they just slaughter the elephants, take off their faces, and leave the body to rot
-Mutation produces tuskless elephants

Question 11

Mutation Definition

Answer 11

-a change in DNA
-Can result from copying errors during cell division, mechanical damage, exposure to chemicals (mutagens) or high-energy radiation
-Very rare
-Provides the raw material on which evolution is based, while recombination and independent assortment rearrange the raw material into new combinations

Question 12

Mechanism of Evolution 2. Natural Selection

Answer 12

-beaks of birds
-Finches have massive bills used for cracking seeds

Question 13

3 Types of Natural Selection

Answer 13

1. Directional Selection
2. Stabalizing Selection
3. Disruptive Selection

Question 14

Directional Selection

Answer 14

-individuals at one phenotypic extreme are favoured
-Ex. large size
-Ex. the finches

Question 15

Stabalizing Selection

Answer 15

-individuals with an intermediate phenotype are favoured
-occurs if there is 2 selective agents operating on both sides of the curve
-Ex. 2 predators and the gall

Question 16

Disruptive Selection

Answer 16

• individuals at both phenotypic extremes are favoured

Question 17

Natural selection is the Mechanism of Adaptive Evolution

Answer 17

1. What is Adaptive Evolution
2. Adaptations results from natural selection
3. Adaptive Evolution can Occur Rapidly
4. Adaptations are not perfect

Question 18

Mechanism of Natural Selection 4. Gene Flow

Answer 18

-alleles move between populations via movement of individuals or gametes
-this causes:
1. Populations to become more similar
2. New alleles can be introduced into a population
-Ex. gene flow introducing alleles for insecticide resistance

Question 19

Key Conceot 3: Natural Selection is the Mechanism of Adaptive Evolution

Answer 19

1. What is adaptive Evolution
2. Adaptations result from natural slection
3. Adaptive evolution can occur rapidly
4. Adaptations are not perfect

Question 20

Adaptations Results from Natural Selection

Answer 20

-Selects of traits that confer advantages
-alleles increase in frequency over time

Question 21

Adaptive Evolution can Occur Rapidly

Answer 21

• Male bighorn sheep that are bigger with a bigger horn will win the battle
• Have been losing land (habitat has been deteriorating)
• They will continue to be hunted- even tho hunters must pay $100,000

Question 22

Adaptations are not Perfect

Answer 22

-Natural selection does not result in a perfect match between organisms and their environments
-Environments are constantly changing, and there are constraints on evolution

Question 23

Why Evolution isn’t Perfect

Answer 23

1. lack of genetic variation
2. evolutionary history
3. ecological trade-offs

Question 24

Lack of genetic variation

Answer 24

• Spraying with DDT killed populations of mosquitoes carrying malaria
• Killed off any form of mutations

Question 25

Evolutionary History

Answer 25

-Whales perfect example of evolutionary history -Evolutionary Constraint: Whales always need to return to the surface to breathe

Question 26

Ecological Trade- offs

Answer 26

- Crab: Decreased mobility due to size - Snow Crabs - claws are small but legs are long trying to get away from predators

Question 27

Adaptive Ecolution is Driven by Ecological Interactions

Answer 27

-Organisms interacting with one another and with their environment -For every fox that caught a bunny, one fox went hungry -Evolution is constantly in motion, and the ecological context is under constant change

Question 28

Key Concept 4: Long-term patterns of evolution are shaped by large-scale patterns

Answer 28

a. Speciation b. Adaptive radiation c. Extinction d. Mass extinction

Question 29

What Drives Speciation in a Single Population:

Answer 29

-Change in gene frequency -There is gene flow between white mice and dark mice -But overtime a river continues to grow between the two -At this particular point, no gene flow would be able to occur -This would cause the formation of 2 separate daughter species (since gene flow isn’t occurring)

Question 30

Species Concept Definition

Answer 30

-Those individuals in the population must be able to have offspring, and those offspring should be fertile

Question 31

Physical Barriers that Result in Reproductive Isolation and Speciation

Answer 31

- Physical Barrier - Mutualism (behaviour) - Ecological Barrier

Question 32

George Cuvier

Answer 32

- discovered extinction - Over evolutionary time we have rates of extinction and speciation

Question 33

Adaptive Radiation Definition

Answer 33

- Repeated speciation events increases the number of speciation in a group

Question 34

Extinction Definition

Answer 34

- species are also lost

Question 35

An Evolutionary Tree Definiton

Answer 35

- a branching diagram that represents the evolutionary history of a group

Question 36

Extant Definition

Answer 36

- is the opposite of extinct (means they are alive today)

Question 37

What does the Cambrian Explosion mean?

Answer 37

- adaptive radiation in animals

Question 38

Key Concept 5: Ecological Interactions and Evolution Exert a Profound Influence on one Another

Answer 38

Evolution observed patterns of change - Bacteria and archaea - Multicellular life - red algae - Animal life