Bio 101 Test 2

Question 1

Evolution

Answer 1

Descent with modification, organisms evolve over time

Question 2

What did Darwin observe while on his voyage that initiated his ideas about evolution?

Answer 2

Closely related species have different shapes and ecological roles.

Question 3

Who was Darwin influenced by?

Answer 3

Georges-Louis Buffon, Erasmus Darwin, George Cuvier, Jean-Baptiste Lamarck, Charles Lyell, Thomas Malthus

Question 4

Georges-Louis Buffon

Answer 4

proposed organisms change with migration

Question 5

Erasmus Darwin

Answer 5

formulated one of the first formal theories on evolution

Question 6

George Cuvier

Answer 6

established extinction as fact

Question 7

Jean-Baptiste Lamarck

Answer 7

proposed evolution via inheritance of acquired characteristics

Question 8

Charles Lyell

Answer 8

geologist who proposed uniformitarianism

Question 9

Thomas Malthus

Answer 9

economist who recognized that populations grow faster than food production

Question 10

Who else besides Darwin proposed evolution?

Answer 10

Erasmus Darwin-proposed one of the first theories

Jean-Baptiste Lamarck- proposed also an evolution theory

Question 11

Lamarck’s theory of evolution

Answer 11

The giraffe neck theory

Question 12

How does natural selection cause evolution?

Answer 12

Natural selection is the differential survival &/or reproduction of organisms whose genetic traits better adapt them to a particular environment.

Question 13

What are the three conditions that must exist for natural selection to occur?

Answer 13

Variation exists for a trait
Variation results in differential fitness
Variation is inherited

Question 14

Fitness

Answer 14

the genetic contribution of an individual to succeeding generations

Question 15

Special types of selection

Answer 15

Artificial selection- selection occurs because of humans

Sexual selection- members of the same species

Question 16

Which type of selection is responsible for divergence of a single species into two?

Answer 16

Disruptive Selection

Question 17

Hardy-Weinberg equilibrium

Answer 17

Allows prediction of genotype frequencies

Question 18

Hardy-Weinberg Equilibrium 5 Assumptions

Answer 18

No mutation takes place.
No genes are transferred to or from other sources.
Random mating is occurring.
The population size is very large.
No natural selection occurs.

Question 19

Which of the five mechanisms of evolution are random?

Answer 19

Genetic Drift

Question 20

Which of the five mechanisms of evolution always result in adaptation?

Answer 20

gene flow, mutation,

Question 21

How to tell if a situation is HWE

Answer 21

If a population is in HWE, it is not evolving.

If a population is not in HWE, it is evolving.

Question 22

Explain in words what q2, q, p, p2 and 2pq represent.

Answer 22

p2 = individuals homozygous for first allele
2pq = individuals heterozygous for both alleles
q2 = individuals homozygous for second allele

Question 23

How genetic drift results in evolution

Answer 23

Could just be a bug getting stepped on or eaten by a predator.

Question 24

Compare and contrast the founder effect and the bottleneck effect.

Answer 24

Founder effect-When organisms go somewhere with no same species and with the alleles they have they procreate
Bottleneck effect- Drastic reduction in population

Question 25

What effect does natural selection have on variation within a population?

Answer 25

Negative frequency-dependent natural selection

Question 26

What effect do each of the 5 mechanisms of evolution have on variation within a population?

Answer 26

Mutation is the ultimate source of variation Gene flow increases variation Non random mating decreases variation Genetic drift-population decreases while allele freq increases Natural selection increases

Question 27

How is variation maintained in populations

Answer 27

Changes in strength or direction of natural selection | Heterozygote advantage

Question 28

What are two evolutionary mechanisms that can increase variation in a population?

Answer 28

Mutation, natural selection

Question 29

Explain at least three reasons that evolution does not result in perfect organisms

Answer 29

Variation doesn't exist Pleiotropy when a single gene controls multiple traits Gene interactions- when a trait is controlled by one or more gene Environment changes, what's needed to survive changed

Question 30

If a population has no genetic variation, can it evolve?

Answer 30

No it cannot

Question 31

What are some modern examples of evidence for evolution by natural (or artificial) selection?

Answer 31

Galapagos finches, domestication of silver foxes

Question 32

What are the 4 types of evidence for evolution?

Answer 32

Fossil record Anatomical/ morphological Molecular Biogeographical

Question 33

What are the 3 types of anatomical evidence for evolution?

Answer 33

homologous structures development vestigial

Question 34

What can we learn from the fossil record?

Answer 34

extinct species, paleontology

Question 35

Differentiate between analogous and homologous structures. Which provide evidence for common ancestry?

Answer 35

Analogous- adaptions to a similar environment but from distantly related organisms Homologous-structures with different appearances and functions that all derived from the same body part in a common ancestor

Question 36

Convergent Evolution

Answer 36

Some plants and animals have similar appearance but are only distantly related

Question 37

Macroevolution

Answer 37

major change, any evolutionary change at or above the level of species

Question 38

Microevolution

Answer 38

small change, any evolutionary change under the level of species

Question 39

What are two examples of macroevolution from class?

Answer 39

Evolution of dinosaurs

Question 40

What is the biological species concept?

Answer 40

groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.”

Question 41

How do we define a species?

Answer 41

A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding

Question 42

How are organisms named and described/classified in biology?

Answer 42

Taxonomy

Question 43

What are the mechanisms of reproductive isolation?

Answer 43

``` Prezygotic Prevent the formation of a zygote Mechanical Gametic Chromosomal Temporal Behavioral Ecological Geological ``` Postzygotic Occur after formation of a zygote Hybrid inviability Hybrid infertility

Question 44

How do these mechanisms of reproductive isolation contribute to speciation?

Answer 44

Cladogenesis- which can be Allopatric speciation involves geographical isolation or Sympatric speciation does not involve geographical isolation

Question 45

How does geography relate to speciation?

Answer 45

Given time, any two isolated populations will diverge because of genetic drift and/or natural selection

Question 46

What are the two mechanisms by which geographically isolated populations diverge into new species?

Answer 46

Genetic drift and natural selection

Question 47

What is polyploidy? How is it related to speciation?

Answer 47

cells of an organism have more than two paired sets of chromosomes More common in plants (30-80% of flowering plants) Occurs infrequently in fish, insects, and amphibian

Question 48

How sympatric speciation occurs

Answer 48

evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region

Question 49

How sympatric speciation occurs

Answer 49

evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region

Question 50

What is character displacement and how does it relate to speciation?

Answer 50

selection acting to lessen resource competition or reproductive interactions causes sympatric species

Question 51

What are the two models for the rate at which speciation occurs? How are they different from one another?

Answer 51

Gradualism is the traditional view | Punctuated equilibrium involves periods of stasis

Question 52

What is adaptive radiation? How do new species arise in adaptive radiation?

Answer 52

``` is the rapid speciation of a single or a few species to fill many ecological niches. Key innovation Release from competition Colonization Extinctions Character displacement ```

Question 53

What are the two types of extinction? How are they different from one another?

Answer 53

Background extinction - natural part of evolution | Mass extinction- catastrophic event

Question 54

How does the rate of extinction compare to the rate of speciation in earth’s history?

Answer 54

The rate of extinction is faster

Question 55

Does evolution always take a long time?

Answer 55

Not in all cases but most yes