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BSCI 160 Shofner > Midterm 2 > Flashcards

Midterm 2 Flashcards

1
Q

Speciation

A

The point where a new trait emerges and new branches form. Becomes different from the parent population and becomes a new species.

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2
Q

Node

A

The point on the tree branch where the ancestral population splits into separate populations

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3
Q

Species (general)

A
  1. Ability to reproduce
  2. The entire unit of the organism
  3. No definition applies to all cells
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4
Q

Biological species concept (Name all factors)

A
  1. It is the explanation of how speciation occurs.
  2. All members can interbreed under natural conditions and produce fertile offspring
  3. Some hybridization is ok
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5
Q

Hybridization

A

When two different species come together and reproduce. These organisms are usually not viable and can’t reproduce.

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6
Q

Sterile

A

Unable to reproduce

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7
Q

Limitations in the biological species concept

A
  1. Asexual organisms. They can’t reproduce the same way sexual organisms do
  2. Not always clear who has the “potential” to interbreed. Can be hard to apply
  3. Can’t be applied to fossils
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8
Q

Crossed boundry

A

When a new species is created and a new population is formed

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9
Q

Boundary arbitary

A

Dog x Wolf. When hybridization leads to fertile offspring

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10
Q

Morphological species

A

Characterizes a species by their body shape and other structural features

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11
Q

prezygotic barriers

A

Prevents the formation of a zygote or a fertilized egg

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12
Q

Habitat isolation

A

They prefer different habitats so they never/rarely mate. Ex: maggot fly

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13
Q

Temporal isolation

A

Species may encounter each other and interbreed but are “ready” to mate at different times. Time and season are important factors. Ex: plants and animals

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14
Q

Behavioral isolation

A

Species may encounter each other but don’t mate because of differences in courtship or behavior. Ex: firefly blinking patterns or bird songs

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15
Q

Mechanical isolation

A

Lock and key. The shape of where you mate has to fit like a puzzle piece. Ex: inspects and flowers

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16
Q

Gametic isolation

A

Games do not recognize each other due to different receptors!!

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17
Q

Reduced hybrid viability

A

When the hybrid is weak and is not able to survive. Not a good fit for the habitat. Ex: sticklebacks

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18
Q

Hybrid infertility

A

When the hybrid is healthy but is unable to reproduce. Ex: mules and tigons

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19
Q

Hybrid breakdown

A

1st generation is fertile and the 2nd generation is weak. Each generation keeps getting weaker and weaker

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20
Q

Postzygotic Barriers

A

Prevents the development of viable or fertile offspring

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21
Q

Habitat Isolation

A

They prefer different habitats so they never/rarely mate

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22
Q

Temporal Isolation

A

Species may encounter each other and interbreed but they are “ready” at different times. The time and season may be different. Ex: Plants and animals

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23
Q

Behavioral Isolation

A

Species may encounter each other but don’t mate because of differences in courtship or behavior.
Ex: Firefly blinking pattern or bird songs

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24
Q

Mechanical isolation

A

Lock and key. The shape of where you mate has to fit like a puzzle piece. Ex: Plants and humans can’t mate

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25
Q

Gametic isolation

A

Gametes do not recognize each other due to different receptors

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26
Q

Reduced hybrid viability

A

When the hybrid is weak and not able to survive. Not a good fit for the environment. Ex: sticklebacks

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27
Q

Hybrid infertility

A

They can be very healthy but they can’t reproduce. Ex: Mules and tigons

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28
Q

Hybrid breakdown

A

1st generation is fertile and 2nd generation gets weak. Each generation keeps breaking down

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29
Q

Macroevolution

A

Broad patterns of evolutionary change above the species level. Can produce major change if there is enough time

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30
Q

Evolutionary change

A

Natural selection, genetic drift, gene flow, mutations

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31
Q

What does evolution is a tinkerer mean?

A

Evolution that includes small modifications to already existing traits.

  • Something with a trait that isn’t being used starts using the trait in a good way
  • Evolutionary dead ends force having to adjust and having to work with what you have.
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32
Q

Anagenesis

A

Patterns of change overtime

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33
Q

Cladogenesis

A

Patterns of diversification

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34
Q

Gradualism

A

Slow change over time and connects to darwinian views.

Example: Distinction among fossil species

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35
Q

Examples of contrasts to gradualism

A

Bacteria reproducing, epigenetics, bottleneck genetic drift

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36
Q

Punctuated equilibrium

A

Emphasizes periods of stasis interspersed with periods of “rapid” change. This means that there is no change and then there is a period of rapid change

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37
Q

Stasis

A

Long periods of subtle evolutionary change. Even though lineages have very small change over time, they will still evolve

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38
Q

Living fossils

A

Organisms that show almost no change from the very beginning. There is still change though, evolution is just not seen and might be part of the molecular level

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39
Q

What is causing stasis

A

It is not always clear about why it happens. Can be due to stabilizing and directional selection

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40
Q

Genetic constraints

A
  1. Continued use of old features in the absence of variation or directional selection
  2. Mosaic evolution
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41
Q

Mosaic evolution

A

When there is a different rate of evolutionary change in various body structures and functions within a population. Changes are taking place independently of other parts.

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42
Q

Rapid change

A

Origin of new species and characteristics over a time period that is quick and short relative tot eh period of stasis. Can be caused by environmental change

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43
Q

Environmental example of rapid change

A

Cambrian explosion (the sudden appearance of every animal phyla)

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44
Q

Extrinsic factors

A

Provides opportunities to occupy previously unavailable niches

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45
Q

Adaptive radiation

A

a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches

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46
Q

Intrinsic factors

A

Characteristics that open up new opportunities

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47
Q

6 Origins of evolutionary novelty

A
  1. Exaptation
  2. Duplication
  3. Serial Homology
  4. Heterochrony
  5. Horizontal gene transfer
  6. Homeotic gene and pattern formation
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48
Q

Exaptation

A

The concept that evolution is seen as a tinkerer. Example: Flowers are modified leaves

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49
Q

Duplication

A

Evolution of genes with novel functions. Duplicated genes can evolve different functions

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50
Q

Globin genes

A

Duplicated genes that can evolve different functions

51
Q

Serial homology

A

Repetitive segments in the same organism. Modifying a specific structure more than once and using it somewhere else

52
Q

Heterochrony

A

Changes in developmental timing can alter the appearance of organisms. Indevolpment

53
Q

Horizontal gene transfer

A

Horizontal movement of individual genes, organelles, or fragments of genomes from one lineage to another. This happens a lot in bacteria

54
Q

Homeotic gene and pattern formation

A

Simple developmental/genetic changes that can have major effects

  • Genes that alter the body plans of organisms
  • Homeotic mutations in Arabidopsis thaliana flowers
55
Q

Hox genes

A

Related genes that are essentially found in all animals. Help lay out the basic body forms of many animals

56
Q

Analogous traits

A

Similarities that are independently evolved. AKA. Convergent

57
Q

Homologous traits

A

Traits that are similar in structure but have very different functions. Traits shared by two or more different species that share a common ancestor.

58
Q

Important aspects of a phylogenetic tree

A
  1. Living species are all the way at the top
  2. Branches represent groups of closely related species
  3. The points on each branch are speciation events
  4. Organisms are united to varying degrees by shared ancestry and share a surprising number of features across a range of lifestyles
59
Q

Problem with constructing trees by fossils

A

Hard to interpret

60
Q

Phylogeny

A

The branches and connections on Darwin’s tree of life

61
Q

Systematics

A

Using classification to reflect the phylogeny of organisms

62
Q

Cladogram

A

An overall estimate of relationships. Groups that are closer together share a more recent common ancestor than those that are farther apart

63
Q

Clade

A

A grouping that includes a common ancestor and all of its descendants. Nested within one another and form a nested hierarchy

64
Q

Synapomorphy

A

Shared derived traits

65
Q

Derived traits

A

Present in the organism but absent in the common ancestor

66
Q

Convergent trait

A

Similarities that evolve independently of each other.

67
Q

Primitive trait

A

Inherited from distant ancestors

68
Q

Methods and evidence scientists use to put dates on events

A
  1. Radiometric dating
  2. Stratigraphy
  3. Molecular clocks
69
Q

Radiometric dating

A

Radioactive elements allow scientists to date rocks and materials directly

70
Q

Stratigraphy

A

A sequence of events from which dates can be extrapolated

71
Q

Molecular clocks

A

Allow scientists to use the amount of genetic divergence between organisms to extrapolate backwards to estimate dates

72
Q

Monophyletic

A

The ancestral species and all of the descendants grouped together. A CLADE

73
Q

Paraphyletic

A

Recent ancestor is included but not all of the descendants. A single origin + does not imply a close relationship

74
Q

Polyphyletic

A

Does not include the recent ancestors. Usually just some of the descendants.

75
Q

Can cladograms be rotated at the node without changing the relationships between the sister taxa?

A

Yes. What matters is which lineage the taxa descends from

76
Q

2 principle techniques for reconstructing phylogeny

A
  1. Parsimony

2. Outgroup analysis

77
Q

Parsimony

A

Cladogram requiring the fewest evolutionary changes is the most preferred. Using the simplest explanation for the distribution of characters gives us a reasonable and explicit goal

78
Q

Outgroup Analysis

A

Distinguishing derived from primitive similarity. The most different from all the other organisms

79
Q

Taxonomic system

A

Species that are closely related are grouped into the same genus

80
Q

Branch points

A

Compare relationships of evolutionary history

81
Q

Root

A

Represents the most common ancestor of all the taxa

82
Q

Criteria for defining a living organism

A
  1. Cellular organization
  2. Means of metabolism
  3. Information storage
  4. Self replication
  5. Responding to stimuli in the environment
  6. Maintaining homeostasis
  7. Reproduction
83
Q

Means of metabolism

A

Different ways to acquire energy and metabolize

84
Q

Information storage

A

Coding for and storing information: RNA and DNA

85
Q

Are viruses living or nonliving

86
Q

Why are viruses nonliving?

A
  1. They can only reproduce inside of a host cell
  2. Since they do not have ribosomes, they have to take over the ribosomes and metabolic state of the host
  3. They do not maintain homeostasis outside of the host cell
87
Q

When was earth formed

A

4.5 billion years ago

88
Q

3 early earth environmental comparisons to today

A
  1. There were a lot of volcanoes relative to now
  2. Oxygen was present in a small amount
  3. CO2, H2, and N2 were all present
89
Q

First form of life

A

Prokaryotes

90
Q

Oxygen levels in early earth

A

Atmospheric oxygen concentration was very low

91
Q

When did oxygen levels begin to increase

A

Photosynthesis

92
Q

How did iron oxide form

A

Oxygen dissolved in water and reacted with iron

93
Q

Banded iron formation

A

Oxygen dissolved in water and reacted with iron. This accumulated in alternating layers of red and dark rock.

94
Q

Earliest evidence of photosynthesis

A

Banded iron formation

95
Q

Fossil stromatolities

A

Provide an early record of photosynthetic organisms

96
Q

What formed stromatolities

A

Cyanobacteria

97
Q

When did prokaryotes rule and change the earth

A

Between march and october

98
Q

When did the first bacteria emerge

99
Q

Before october

A

Only single celled organisms were around

100
Q

After october

A

Multicellular organisms began to show up

101
Q

November

A

Plants invaded the land and most major animal groups appeared in oceans

102
Q

Early december

A

Flowers and mammals evolved

103
Q

December 26

A

Dinosaurs ruled the world until the asteroids hit. Only the birds survived

104
Q

December 31st

A

Humans began existing

105
Q

Modern Cell theory

A
  1. The cell is the smallest living unit in all organisms
  2. All living things are made up of cells
  3. All cells come from pre existing cells
106
Q

2 types of prokaryotes

A

Bacteria and Archea

107
Q

Type of Eukaryote

108
Q

Prokaryote

A

Unicellular organisms

109
Q

Eukaryote

A

Unicellular or multicellular organisms

110
Q

Which is closer to the Eukarya

111
Q

Similarities between Prokaryotes and Eukaryotes

A
  1. DNA
  2. Ribosomes
  3. Cytoplasm
  4. Cell membrane
112
Q

What do ribosomes do

A

Ribosomes make protein

113
Q

What does the cell membrane

A

Controls what goes in and out of the cells - maintaining hoeostasis

114
Q

Unique to prokaryotic

A
  • No nucleus, free roaming genetic information
  • No membrane bound organelles
  • No nuclear envelope around genetic material
  • Circular DNA
  • Binary fission: No mitosis or meiosis
  • Few genes in the plasmids
115
Q

Unique to eukaryotic

A
  • More detailed cell materials
  • Some don’t have cells walls while some do
  • More complex and larger
  • Has nucleus
  • Has membrane bound organelles: nucleus, mitochondria, endoplasmic reticulum, golgi appartus
116
Q

Circular Dna

A

Has genes for resistance

117
Q

What was the dominant form of life on earth

A

Prokaryotes

118
Q

Prokaryotes were ___x the mass of all eukaryotes

119
Q

What type of respiration do prokaryotes do?

A
  • Aerobic
  • Anearobic
  • Photosynthesis
120
Q

Where does all of our metabolism come from

A

Prokaryotic metabolism

121
Q

What is the molecule that bacteria has in their cell wall that is not found anywhere else

A

Peptidoglycan

122
Q

Peptidoglycan

A

Only found in the cell wall of bacteria. They stack up in certain groups of bacteria

123
Q

How many prokaryotic cells are in your gut

124
Q

How many cells make up your body

BSCI 160 Shofner (2 decks)

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