Evolution

Question 1

Evidence that Life Descended from a Common Ancestor

Answer 1

1. All life possesses the same macromolecules.
2. Common mechanisms of DNA replication
3. Common metabolic pathways
4. Common genetic code
5. Similarity of form
6. Similarity of DNA sequences
7. Fossil record`

Question 2

3 Domains of Life

Answer 2

Eukarya, Prokaryotes, Archaea

Question 3

Evidence that Archaea and Eukaryotes are Relatives

Answer 3

ribosomal proteins, translation factors, proteins involved in transcription

Question 4

2 Parts of Evolution

Answer 4

Anagenis - change in lineage over time

Cladogenesis - splitting of one lineage into 2

Question 5

Basic Idea of Evolution by Natural Selection

Answer 5

1. Individuals within a population are variable.
2. The variations among individuals are passed from parents to offspring.
3. In early generation, some individuals are more successful at surviving and reproducing.
4. The individuals with the most favorable variations are naturally selected.

Question 6

Jean-Baptiste Lamarck

Answer 6

French biologist argued for evolution through inheritance of acquired characteristics

Question 7

Thomas Malthus

Answer 7

English economist and demographer, thought population will eventually outstrip food supply

Question 8

Charles Lyell

Answer 8

English geologist, assumed uniformitarianism (processes we see today also acted in the past)

Question 9

3 Elements of Natural Selection

Answer 9

variation, heritability, differential success

Question 10

5 Assumptions of Hardy-Weinberg

Answer 10

1. Random mating
2. No gene flow
3. No genetic drift (population is large)
4. No mutations
5. No natural selection

Question 11

Forces that Shape Allele Frequencies

Answer 11

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

Question 12

Mutation

Answer 12

ultimate source of all genetic variation

types - point, germ line, chromosomal, small insertions/deletions

Question 13

Point Mutation

Answer 13

change in a single letter of DNA

Question 14

Germ Line Mutation

Answer 14

mutation in cells that give rise to sperm/eggs

Question 15

Chromosomal Mutation

Answer 15

chromosomes are rearranged, lost, or duplicated (eg Down’s Syndrome)

Question 16

Directional Selection

Answer 16

results when one allele confers higher fitness relative to other alleles

Question 17

Purifying Selection

Answer 17

eliminates deleterious alleles

Question 18

Balancing Selection

Answer 18

occurs when heterozygotes have higher fitness than either homozygote

Question 19

Genetic Drift

Answer 19

change in allele frequencies due to random sampling

Question 20

Characteristics of Genetic Drift

Answer 20

1. effect of drift is greater in small populations
2. allele frequencies change at random (may go up or down)
3. leads to loss of genetic variation over time
4. drift can sometimes lead to the fixation of harmful alleles

Question 21

Population Bottleneck

Answer 21

reduction in size of an existing population

Question 22

Founder Event

Answer 22

establishment of a new population of a smaller size, explains the frequency of diseases in many human populations

Question 23

Gene Flow

Answer 23

transfer of alleles between populations due to the movement of individuals or their gametes
reduces differences in genotype between populations

Question 24

Sexual Selection

Answer 24

a form of selection in which individuals with particular inherited characteristics are more likely than other individuals to acquire mates

Question 25

2 Models of Sexual Selection

Answer 25

1. Fisher’s “Runaway” Model - females prefer males with extreme traits, giving rise to sons with the extreme trait and daughters with a preference for the extreme trait
2. Good Genes Model - females prefer males with certain traits because these traits are associated with higher fitness

Question 26

Synaptomorphy

Answer 26

shared derived character

Question 27

3 Groups

Answer 27

monophyletic group - ancestor and all descendants
paraphyletic group - ancestor and some descendants
polyphyletic group - different ancestors

Question 28

Oparin-Haldane Hypothesis

Answer 28

early atmosphere had no oxygen, energy provided by lightning and UV radiation; organic compounds formed from simpler molecules, hypothesis later supported by lab experiments

Question 29

The Fossil Record

Answer 29

fossil - any recognizable evidence of preexisting life

Question 30

Bias of Fossil Record

Answer 30

mostly hard anatomy preserved, record is best for organisms who lived in areas where they were likely to be preserved (most fossils occur in sedimentary rock)

Question 31

Radiometric Dating

Answer 31

uses isotopes of unstable naturally occurring elements, isotopes decay

Question 32

Species Concepts

Answer 32

Biological Species Concept - groups of actually or potentially interbreeding organisms that are reproductively isolated from other such groups
Morphological Species Concept
Phylogenetic Species Concept

Question 33

Pre-Mating, Prezygotic Sources of Reproductive Isolation

Answer 33

geographic barrier
habitat isolation
pollinator isolation
temporal isolation
behavioral (mating) isolation

Question 34

Post-Mating, Prezygotic Sources of Reproductive Isolation

Answer 34

mechanical isolation

gametic isolation

Question 35

Postzygotic Sources of Reproductive Isolation

Answer 35

1. hybrid inviability
2. hybrid sterility
3. hybrid breakdown

Question 36

Hybrid Breakdown

Answer 36

1st generation of offspring is viable and fertile, but the 2nd generation has reduced viability and fertility

Question 37

Temporal Isolation

Answer 37

species mate and breed at different times of day/month/year

Question 38

Allopatric Speciation

Answer 38

occurs when populations are separated by a physical barrier that prevents gene flow

Question 39

Parapatric Speciation

Answer 39

populations are neighboring but separated by an extreme change in habitat (like copperopolis)

Question 40

Sympatric Speciation

Answer 40

new species evolve from a single ancestral species while inhabiting the same geographic region