Unit 1: Evolution I and II

Question 1

Who is the famous scientist who observed variation in finches?

Answer 1

Charles Darwin

Question 2

What was the name of Darwin’s voyage?

Answer 2

Voyage of the Beagle

Question 3

What was Darwin’s publication?

Answer 3

“On the Origin of Species”

Question 4

Darwin best described biological evolution as what?

Answer 4

Descent with modification through variation and natural selection

Question 5

Variation

Answer 5

Variation within species

Question 6

Natural Selection

Answer 6

Population change over time where individuals with favorable traits pass them onto offspring in an effort to maintain survival

Question 7

Evolutionary Adaptation

Answer 7

Form of evolutionary change in which a population’s characteristics change to suit environment

Question 8

What is the main difference between microevolution and macroevolution?

Answer 8

Microevolution relates to changes in a single gene in a population over time, whereas macroevolution is the cumulation of changes in genes that results in the formation of a new related species

Question 9

A population of organisms is described as NN, Nn, and nn. What are the genotypic meanings of these?

Answer 9

NN: Homozygous dominant
Nn: Heterozygous
nn: Homozygous recessive

Question 10

Darwinian Fitness is best described as the _____ of likelihood that a _____ will contribute to the ____ ____ of the next ____ as compared with other genotypes. It is a measure of ____ success and the average of members in a population is called the _____ _____ of the population.

Answer 10

relative; genotype; gene pool; generation
reproductive; mean fitness

Question 11

What are the four classes of evolutionary mechanisms?

Answer 11

Selection, random genetic drift, gene flow, and non-random mating.

Question 12

What is the relationship between heritable variation and environmental factors?

Answer 12

Heritable variation is where survival depends partially on inherited traits. Environmental factors filter heritable variations where favoritism is swayed to others.

Question 13

True or False:

An organism is the smallest unit of evolutionary change.

Answer 13

False – natural selection acts on individuals, but evolution acts on the population

Question 14

True or False:

Natural selection can only act on heritable traits AND it is a creative tool.

Answer 14

False – while natural selection does only act on heritable traits, it is a remodeling tool, not a creative one.

Question 15

What are the three tenants for natural selection to occur?

Answer 15

1. Variation must exist among individuals in a population.
2. Variation among individuals must result in differences in the number of offspring surviving in the next population.
3. Variation must be genetically inherited.

Question 16

Match the following letters with its number:

A: directional
B: stabilizing
C: disruptive
D: balancing
E: sexual

1: intermediate favoritism
2: extreme favoritism
3: more favoritism on ends
4: advantage over others in same sex and species
5: maintains genetic diversity

Answer 16

A:2
B:1
C:3
D:5
E:4

Question 17

Describe heterozygote advantage and give an example.

Answer 17

Heterozygote advantage: heterozygous genotype is promoted

Example: malaria (AA get it, AS “immune,” SS have sickle-cell anemia)

Question 18

Intrasexual Selection

Answer 18

Selection between members of the same sex; male-male competition

Question 19

Intersexual Selection

Answer 19

Selection between members of the opposite sex; female choice

Question 20

Sexual Dimorphism

Answer 20

Sexual selection acts on males more strongly than on females

Question 21

Explain genetic drift and provide two examples.

Answer 21

Genetic Drift: when allele frequencies fluctuate randomly from one generation to another, and favors either loss or fixation of an allele.

Examples: bottleneck effect; founder effect

Question 22

Gene Flow

Answer 22

When emigration or immigration causes alleles to be gained or lost

Question 23

How is gene flow different from genetic drift, especially the founder effect?

Answer 23

In genetic drift, allele frequency is changed within that population without mixing with another population. Gene flow is a change in allele frequency due to movement into or out of a population.

Question 24

Assortative Mating

Answer 24

Mating where individuals with similar phenotypes are more likely to mate, results in increases of homozygous genotypes

Question 25

Disassortative Mating

Answer 25

Mating where individuals with dissimilar phenotypes mate, increases proportion of heterozygous phenotypes

Question 26

Inbreeding

Answer 26

Mating between genetically related individuals; results in increase in homozygous genotypes and usually occurs in small populations

Question 27

How does the fossil record assist in the field of evolutionary biology?

Answer 27

The fossil record is a vast collection of preserved body parts of past and ancient organisms where species could be extinct or extant. It helps in showing changes such as larger size and complexity in teeth development.

Question 28

Developmental Homology

Answer 28

Homology that looks at early development of different species to draw on homologous strictures that have different functions

Question 29

Anatomical Homology

Answer 29

Homology looking at organisms and how they have similar structures across anatomical structures, but different functions

Question 30

Molecular Homology

Answer 30

Homology that looks at similarities among organisms at the molecular level

Question 31

Vestigal Structures

Answer 31

Organs not needed by the organism that are remnant of important structures in ancestors

Example: wisdom teeth, appendix

Question 32

Biogeography

Answer 32

Study of geographical distribution of extinct and modern species

Question 33

Convergent Evolution

Answer 33

When species from different lineages show similar characteristics because they occupy similar environments

Question 34

What species is the main driving force behind artificial selection?

Answer 34

Humans