Chapter 24 and 25 Flashcards

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1
Q

Species

A

Defined as an evolutionarily independent population or group of populations

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2
Q

Biological species concept

A

members of populations that actually or potentially interbreed in nature, not according to similarity of appearance

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3
Q

Prezygotic isolation

A

mechanisms of separation of different species to keep them from creating offspring by preventing the gametes from forming a zygote.

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4
Q

Postzygotic isolation

A

Reproductive isolation in which the hybrid offspring does not survive or reproduce

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5
Q

Morphospecies concept

A

Researches identify evolutionarily independent lineages by differences in size, shape, or other morphological features

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6
Q

Polymorphic species

A

A species that over 2 distinct phenotypes in the same interbreeding population

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6
Q

Cryptic species

A

Differ in tratis other than morphology

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7
Q

Phylogenetic species concept

A

Identifies species based on evolutionary history of populations

Definition that species are the smallest monophyletic group in a phylogenetic tree

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8
Q

Monophyletic group (lineage, clade)

A

include a single common ancestor and all of its descendants

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9
Q

Synapomorphy

A

Trait that is found in certain groups of organisms and their common ancestor but is missing more distant ancestors

These are what identifies monophyletic groups

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10
Q

Three common species concepts

A

Biological species
Morphospecies
Phylogenetic species

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11
Q

Allopatry

A

describes a population or species that is physically isolated from other similar groups by an extrinsic barrier to dispersal

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12
Q

Allopatric speciation

A

Speciation occurs when populations of the same species become geographically isolated

Starts in two ways called dispersal and vicariance

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13
Q

Dispersal

A

Movement of individuals from one place to another from place of origin to place of living and breeding

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14
Q

Vicariance

A

The physical splitting of a habitat by a geographic barrier

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15
Q

Biogeography

A

Study of how species and populations are distributed geographically

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16
Q

Sympatry

A

Condition in which two or more populations live in the same geographical area or close enough to permit interbreeding

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17
Q

Sympatric speciation

A

Speciation that occurs even though populations live within the same geographical area

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18
Q

Niche

A

Range of resources that a species can use and the range of conditions that it can tolerate

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19
Q

Polyploidy

A

Condition of possessing more than two complete sets of chromosomes, is caused by a massive error in mitosis or meiosis

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20
Q

Two types of polyploids

A

Autopolyploid

Allopolyploid

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21
Q

Autopolyploid

A

Individuals are produced when a mutation results in a doubling of chromosome number and the chromosomes all come from the same species

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22
Q

Allopolyploid

A

Individuals are created when parents of different species mate and then an error in mitosis occurs and it results in viable offspring with two full sets of chromosomes

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23
Q

Reinforcement

A

The natural selection for traits that prevent interbreeding among recently diverged species

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24
Q

Sympathic

A

2 species live in the same area

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25
Q

Allopatric

A

2 species live in different areas

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26
Q

Hybrid zone

A

Geographic area where interbreeding occurs and hybrid offspring is common

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27
Q

Hybrid sterility

A

Postzygotic mechanism occurs when the offspring of two different species are sterile or have reduced fertility

Unable to produce viable offspring themselves

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28
Q

Habitat isolation

A

Prezygotic mechanism that refers to species being isolated by differences in their habitats or ecological niches, reducing the chance of encountering and mating with each other

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29
Q

Mechanical isolation

A

Prezygotic mechanism involves structural differences in reproductive organs that prevent successful mating between different species

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30
Q

Temporal isolation

A

Prezygotic mechanism that involves differences of reproductive activates such as breeding seasons, flowering times, or mating rituals, preventing the interbreeding of different species.

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31
Q

Phylogeny

A

Evolutionary history of a group of organisms

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32
Q

Phylogenetic tree

A

Branching diagram that depicts the evolutionary relationships among species or other taxa

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33
Q

Systematics

A

Discipline of biology that characterizes and classifes relationships among all organisms on earth

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34
Q

tree of life

A

phylogenetic tree that includes all organisms

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35
Q

taxa

A

Any named group of organisms at any level of a classification system

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36
Q

branches

A

part of phylogenetic tree that represents populations through time

37
Q

Sister groups

A

Two lineages that are each other’s closes relatives, represented by two branches emerging from a node in a phylogenetic tree

38
Q

polytomy

A

Node in a phylogenetic tree that depicts an ancestral branch dividing into three or more descendant branches

39
Q

Trait

A

Any observable characteristic at any level of observation of an individual

40
Q

Outgroup

A

taxon that is not part of the taxonomic group being studied but is closely related

Added to establish direction of change of each character

41
Q

Ancestral trait

A

Trait that existed as an ancestor

42
Q

Derived trait

A

Modified form of an ancestral trait, found in a descendant

43
Q

Synapomorphy

A

Trait found in two or more taxa that is present in their most recent common ancestor but is missing in more distant ancestors

Allow biologists to recognize monophyletic groups

44
Q

homology

A

Similarity among organisms of different species due to shared ancestry

45
Q

Homoplasy

A

Similarity among organisms of different species due to reasons other than common ancestry

46
Q

Parsimony

A

The principle that most likely explanation for a phenomenon is the one that implies the least amount of change

47
Q

bioinformatics

A

A discipline at the intersection of biology, computer science, and statistics, concerned with the storage, analysis, and presentation of biological data

48
Q

Fossil record

A

Total collection of fossils that paleontologists and amateur collectors have found throughout the world and archived in thousands of private collections

49
Q

Intact fossil

A

Forms when decomposition does not occur and the organic remains are preserved intact

50
Q

Compression fossil

A

Forms when sediments accumulate on top of the organism

51
Q

Cast fossil

A

Organism decomposes after buried and hole is replaced with minerals

52
Q

Permineralized fossil

A

Forms when organisms decompose extremely slowly

Dissolved minerals gradually infiltrate cells

53
Q

Trace fossils

A

Forms when sedimentation and mineralization preserve indirect evidence of an organism such as footprints, tracks, burrows, feeding marks and feces

54
Q

Conditions in which fossils form

A

buried rapidly
decompose quick

55
Q

Habitat bias in fossilization

A

Organisms that live in areas where sediments are actively being deposited, like beaches, mudflats, and swamps are more likely to form fossils than are organisms that live in other habitats.

56
Q

Taxonomic bias

A

Since slow decay is essential to fossilization, organisms with hard parts such as bones or shells are most likely to leave fossil evidence

57
Q

Tissue bias

A

Some organism’s tissues like teeth or pollen grains are encased in outer coats that resist decay, thus they can fossilize easily

58
Q

Temporal bias

A

Recent fossils are much more common than than older fossils

59
Q

Abundance bias

A

Organisms that are abundant, widespread, or present on earth for long periods of time leave evidence much more often than do species that are rare, local or ephemeral

60
Q

Radiometric dating

A

Researchers used this to assign absolute dates to events in the fossil record

Based on the well studied decay rates of certain radioactive isotopes

61
Q

Precambrian

A

The interval between the formation of the Earth, to the appearance of most animal groups about 541 million years ago

Unicellular organisms were dominant for most of this era
Oxygen was absent from the oceans and atmosphere for almost 2 billion years

Divided into Hadean, Archaean, and Proterozoic eons

62
Q

Phanerozoic Eon

A

Interval between 541 mya and the present

Divided into 3 eras Paleozoic, Mesozoic and Cenozoic

63
Q

Paleozoic (ancient life)

A

Origin and initial diversification of animals, land plants, and fungi

64
Q

Mesozoic era (middle life)

A

Begins with end-Permian extinction events and ends with the extinction of dinosaurs and other groups

Gymnosperms were dominant plants and dinosaurs were dominant vertebrates

65
Q

Cenozoic era (recent life)

A

Angiosperms were dominant plants, birds and mammals were the dominant vertabrates

66
Q

Anthropocene

A

Proposed name of new, current epoch in the geologic time scale to reflect the dramatic physical, chemical, and biological changes that humans are causing on earth.

67
Q

Adaptive radiation

A

Rapid evolutionary diversification of a single lineage into a wide variety of adaptive forms

68
Q

Three hallmarks of adaptive radiation

A

Monophyletic group
Speciated rapidly
Diversified ecologically into many niches.

69
Q

Two general mechanisms that can trigger adaptive radiations

A

Factors extrinsic to organisms, such as favorable new conditions in the environment

Factors intrinsic to organisms, such as the evolution of key morphological, physiological or behavioral traits

70
Q

Ecological opportunity

A

Term used to describe the processes that can produce a diverse group of species from a single colonizing ancestor

71
Q

Morphological, Physiological, Behavioral innovation

A

Allows descendants to live in new areas, exploit new sources of food or select mates in new ways, triggering diversification events in the history of life.

72
Q

Cambrian explosion

A

Rapid diversification of animal body types and lineages that occurred during a 50-million-year-period about 541 mya at the start of the proterozoic eon

73
Q

Fauna

A

All the animals that live in a particular region, period, or environment

74
Q

First microfossils fossils

A

Appeared during Ediacaran and included sponges, jellyfish, and comb jellies, as well as fossilized burrows, tracks, and other traces from unidentified animals

None of them had shells, limbs, heads

Filtered or absorbed organic material from water to make a living

75
Q

Cabrian macroscopic fossils

A

Sponges, jellyfish, combjellies were abundant with these

Species in this Cambrain fauna, slithered, swam, and crawled and had skeletons

76
Q

What triggered Cambrian Explosion

A

Higher oxygen levels
Rise of algae
Evolution of predation
New niches beget more new niches
New genes new bodies

77
Q

Higher oxygen levels

A

Increased oxygen levels made aerobic respiration more efficient and it supported larger bodies and more active movements

78
Q

Rise of algae

A

The photosynthetic nutrient rich algae increase during this time lead to a higher quality food source for animals

79
Q

Evolution of predation

A

During the Cambrian explosion, animals started to eat other animals and it resulted in natural selection for prey animals in terms of defense mechanisms

80
Q

New genes New bodies

A

During the Cambrian explosion, gene duplication and diversification lead to
the Hox gene which signaled where cells are in the embryo. It lead for larger, more complex bodies to survive

81
Q

Mass extinction

A

rapid extinction of a large number of diverse species around the world.

82
Q

Background extinction

A

Refers to lower, average rate of extinction observed when a mass extinction is not occurring

Occurs when normal environmental change, emerging disease, predation pressure, or competition with other species reduces certain populations to

83
Q

End Permian Extinction

A

“Mother of Mass Extinctions”

Flood basalts or outpouring of molten rock belched heat, CO2, and sulfur dioxide into the atmosphere.

High amounts of sulfur dioxide caused acid rain that devastated plants and organisms.

Flood basalts ignited coal fires that pumped toxic ash, including mercury, into the air

Oceans lacked oxygen and became fatal to organisms that relied on aerobic respiration

Sea level dropped dramatically, reducing habitat

84
Q

Impact hypothesis

A

Hypothesis that a collision between Earth and asteroid caused a mass extinction that ended the Cretaceous, 66 million years ago

85
Q

Description of the asterioid

A

Size of Mount Everest

Would have caused tsunamis, and acid rain due to sulfate-containing rock in the asteroid that reacted with water in the atmosphere to form sulfuric acid

The dust, ash, and soot would have blocked the sun and caused rapid global cooling

86
Q

Paraphyletic

A

It includes an ancestral population and some of its decendants not all

87
Q

Polyphyletic

A

shares similar traits but does not include the most recent common ancestor

88
Q

Convergent evolution

A

the process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities.

89
Q

Self-fertilization

A

Most extreme form of inbreeding

Fusion of male and female gametes (sex cells) produced by the same individual

90
Q

What do fossil records show

A

What organisms in the past looked like
Where they lived
When they existed

91
Q

Artiodactyls

A

Any of various hoofed mammals of the order Artiodactyla, having an even number of toes on each foot. Artiodactyls include the pig, sheep, ox, deer, giraffe, and hippopotamus.