Lecture 6: Evolution, Genes, and Ecology Flashcards

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1
Q

Mutations that arise in what regions of the DNA are often eliminated by Natural selection?

A

noncoding

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2
Q

If mutations accumulate in noncoding regions at a constant rate, differences in the DNA sequences can serve as what?

A

a molecular clock

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3
Q

What does a molecular clock do?

A

It indexes the time at which two species diverged

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4
Q

Large difference imply divergence in the distant ____

A

past

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5
Q

Small differences in DNA sequences imply a more _____ common ancestor

A

recent

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6
Q

How are molecular clocks calibrated?

A

The fossil record and biogeographically with independent data

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7
Q

Phylogenies can help reveal what type of convergence?

A

Homoplastic

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8
Q

Similar traits have evolved independently in different ____

A

clades

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9
Q

What can phylogenies illuminate?

A

The stepwise evolution of complex characters

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10
Q

How do the initial stages of a character evolve?

A

as an adaptation to some environmental selective pressure

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11
Q

How can we map character transitions onto phylogenies?

A

using the principal of parsimony

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12
Q

What was used to understand how COVID- 19 spread?

A

phylogenetic analysis

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13
Q

What did the phylogenetic analysis of COVID-19 show?

A

that there were at least 9 introductions of the strains

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14
Q

What eon and around what year was the formation of the earth and moon?

A

The Hadean eon and around 4.5 BYA

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15
Q

What were the eras in the Archean Eon?

A
  1. Eqarchean
  2. Paleoarchean
  3. Meoarchean
  4. Neoarchean
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15
Q

What era and eon did prokaryotes appear?

A

The paleoarchean era in the Archean eon

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16
Q

What era and eon was the oldest fossil found and what was it?

A

It was in the paleoarchean era in the archean eon and it was a stromalites

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16
Q

What era and eon did the appearance of eukaryotes occur?

A

The neoarchean era in the archean eon

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16
Q

What eras are in the Proterozoic eon?

A

Paleoproterozoic
mezoproterozoic
neoproterozoic

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17
Q

When was the first multicellular life found, name the era and eon?

A

The Neoproterozoic era in the proterozoic eon

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17
Q

What eras are in the phanerozoic eon?

A
  1. Paleozoic
  2. Mesozoic
  3. Cenozoic
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17
Q

What periods are in the Paleozoic era?

A
  1. cambrian
  2. Ordovician
  3. Silurian
  4. Devonian
  5. Carboniferous
  6. Permian
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18
Q

What happened in the cambrian period?

A

The first true vertebrates appear

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18
Q

What happened in the ordovician period, and what era is it part of ?

A

Plants began to colonize land and it is in the palezoic

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18
Q

What happened in the devonian period and what era is it in?

A

The first animals with four legs evolved and it is in the paleozoic

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19
Q

What happened in the carboniferious period and what era is it?

A

It is the paleozoic era and the first amphibians developed

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20
Q

What happened in the permian period and what era is it a part of?

A

Four-legged animals split into mammal-like reptiles and reptiles and it is in the paleozoic era

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21
Q

What period and era did the first mammal appear?

A

The Triassis period in the Mesozoic era

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22
Q

What period and era did the first bird appear?

A

The jurassic period in the Mesozoic era

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23
Q

What period and era did the first flowering plants evolve?

A

The cretaceous period in the Mesozoic era

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24
Q

What periods are in the cenozoic era?

A
  1. Paleocene
  2. Eocene
  3. Oliocene
  4. Miocene
  5. Pliocene
  6. Pleistocene
  7. Halocene
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25
Q

What period and era did the first primates occur?

A

The paleocene period in the cenozoic era

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26
Q

What period and era did the hominis (early ancestors of humans- evolve)?

A

Miocene period in the cenozoic era

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27
Q

What period and era did the first “modern” humans evolve in Africa?

A

Pleistocene period and cenozoic era

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28
Q

How is geologic time divided into?

A

Four eons—> eras—> period

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29
Q

When did no rocks exist?

A

In the Hadean eon for the first 500-700 million years,

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30
Q

Because the Hadean Earth was pummeled by asteroids which could potentially do what to the oceans?

A

vaporize

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31
Q

If CO2 levels shift what do they affect?

A

The temperature

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32
Q

The early atmosphere probably had what type of levels of CO2?

A

High

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33
Q

What slowly vaporized from molten rock?

A

water

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34
Q

What weathering convert rock to?

A

soil

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35
Q

What can CO2 form?

A

carbonic acid

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36
Q

What is carbonic acid released by?

A

Bicarbonate ions from rock (HCO3- and Ca2+)

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37
Q

Decreases in CO2 cause a what to Earth’s temperature?

A

decrease

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38
Q

What are plates?

A

Earth’s crust in forms of rigid slabs of rock

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39
Q

What is Rodinia?

A

All continents

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40
Q

What is Gondwana?

A

All current southern Hemisphere continents

41
Q

What is Pangea?

A

all continents formed from Gondwana

42
Q

What eon did Life emerge from?

A

Archean eon

43
Q

What potential year did life occur?

A

3.7 BYA

44
Q

What is the Proterozoic eon characterized by?

A

The formation of Rodinia

45
Q

When did Rodinia break up?

A

Before the Phaneozoic eon

46
Q

What did the Cambrian period show diversification of?

A

multicellular organisms

47
Q

What was the Miller- Urey Experiment reproduce?

A

The early atmosphere

48
Q

What type of atmosphere did the Miller Urey try to recreate?

A

a reducing atmosphere rich in hydrogen with no oxygen gas

49
Q

What did the Miller-Urey experiment find within a week?

A

That methane gas was converted into other simple carbon compounds

50
Q

What did Miller Urey conclude from their experiment?

A

That the key molecules of earth could have formed on early earth

51
Q

What can be assumed about primitive organism?

A

They could have been autotrophic or heterotrophic

52
Q

What are some landmarks in the evolution of metabolism

A
  1. oxygenic photosynthesis
  2. carbon fixation
  3. nitrogen fixation
53
Q

What is oxygenic photsynthesis?

A

Photosynthesis releases oxygen

54
Q

What is carbon fixation?

A

photosynthetic organisms turn inorganic carbon into organic compounds

55
Q

What is nitrogen fixation?

A

any natural or industrial processes that lead to free nitrogen

56
Q

What may have been the first genetic material?

A

RNA

57
Q

____ bubbles could increase the probability of metabolic reactions

A

lipid

58
Q

What type of organisms are the first life-forms

A

single-celled organisms

59
Q

What are the two main formations of 3.5-3.8 BY rocks that have been found that are interpreted to be biological in origin?

A

Kaapvaal craton and Pilbara craton

60
Q

What are stromatolites?

A

They are mats of cyanobacterial cells that trap mineral deposits

61
Q

What are stromatolites indirect evidence for?

A

ancient life

62
Q

What is the oldest stromatolites?

A

2.7 Billion years old

63
Q

What factors affect an organisms’ survival?

A

Climate and atmosphere

64
Q

Dramatic shifts in what factors have led to mass extinctions?

A

climate and atmosphere

65
Q

Did plants contribute to glaciations?

A

Yes

66
Q

What two glaciations did plants contribute to?

A

colonization of land by plants was followed by gradual cooling and abrupt glaciation 488 to 444 mya
2. vascular plants diversification is concurrent with the second glaciation 400-360 MYA

67
Q

What are vascular plants?

A

They are plants that lignified tissues for conducting water and minerals throughout the plants

68
Q

How did the mitochondria and chloroplast enter early eukaryotic cells?

A

Endosymbiosis

69
Q

What are Mitochondria descendants of?

A

a parasite

70
Q

What are chloroplasts derived from?

A

cyanobacteria

71
Q

What leads to cell specialization?

A

Multicellularity

72
Q

What type of organisms constitute about half the biomass on Earth?

A

Unicellular prokaryotes

73
Q

Whay multicellularity allow organisms to do?

A

To deal with environment in novel ways through differentiation

74
Q

What does multicellularity require cells to do?

A

TO connect to each other and communicate

75
Q

What varies among cells to allow specialization?

A

gene expression

76
Q

What increases genetic diversity?

A

sexual reproduction

77
Q

How does sexual reproduction allow for great genetic diversity?

A
  1. Meiosis
  2. Crossing over
78
Q

Rapid what occurred durng the Cambrian era?

A

diversification

79
Q

When did the first multicellular animals appear?

A

50 million years following the cambrian explosion

80
Q

After cambrian radiation what began to colonize terrestrial environments?

A

plants and then animals

81
Q

What protected organisms on land by creating the ozone layer?

A

evolution of photosynthesis

82
Q

What happened to marine species and terrestrial vertebrates at the end of the permian era?

A

80% of marine species and 70% of terrestrial vertebrates were extinct

83
Q

What is the time period for the Triassic period?

A

251.9 to 201.4 MYA

84
Q

What is the time period for the Jurassic period?

A

201.4 to 145 MYA

85
Q

What is the time period for the cretaceous period?

A

145 to 66 million years ago

86
Q

What ended the Mesozoic era?

A

The K/T mass extinction event

87
Q

What is the time period for the Paleogene period?

A

66 to 23 MYA

88
Q

What is the time period for the Neogene period?

A

23 to 2.6 MYA

89
Q

What is the time period for the Quaternary period?

A

2.6 to 0 MYA

90
Q

What is the Cenozoic period categorized by?

A
  1. rise of mammals
  2. rise of grasslands
  3. origins of humans
  4. sixth mass extinction ongoing
91
Q

What are the irregularly shaped plates of rock that float on Earth’s semisolid mantel called?

A

plate tectonic

92
Q

What is it called when the currents in the mantle cause the plates, and continents to move?

A

Continental drift

93
Q

What did Pangea separate into?

A

Laurasia and Gondwana

94
Q

What year was Pangea?

A

240 MYA

95
Q

What continents were in Laurasia?

A

North America, Europe, and Asia

96
Q

What continents were in Gondwana?

A

South America, Africa, Antartica, Austrialia, India, Madagascar, New Zealand

97
Q

What year did Laurasia and Gondwana form?

A

170 MYA

98
Q

When did Gondwana begin to breakup?

A

120 MYA

99
Q

How did Gondwana breakup?

A

South America and Africa, India and Madagascar and Antarctica and Australia

100
Q

When did the Rift of Australia vs. India and Madagascar occur?

A

110 MYA

101
Q

When did Africa and South America separate and Madagascar and India separate?

A

90 MYA

102
Q

When was the KT-Extinction?

A

65 MYA

103
Q

When did India collide with Asia?

A

20 MYA

104
Q

Species with a ______ distribution live in suitable habitats throughout a geographical area.

A

continuous

105
Q

What is disjunct distribution?

A

closely related species living in widely separated locations?

106
Q

What two phenomena can create disjunct distributions?

A
  1. dispersal
  2. vicariance
107
Q

What is dispersal?

A

the movement of organisms away from their place of origin

108
Q

What is vicariance?

A

The fragmentation of a once-continuous geographical distribution by external factors