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Evolutionary Biology > Evolution of the Vertebrates > Flashcards

Evolution of the Vertebrates Flashcards

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1
Q

Vertebrates are animals that have?

A

Vertebral column or the backbone.

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2
Q

Four key characters of chordates:

A

Muscular, post-anal tail
Notochord
Dorsal, hollow nerve cord
Pharyngeal slits or clefts

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3
Q

a longitudinal, flexible rod between the digestive tube and nerve cord

A

Notochord

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4
Q

Function of notocord

A

provides skeletal support

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5
Q

In most vertebrates, a more complex,_________ skeleton develops

A

jointed

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6
Q

Notochord:
In most vertebrates, the adult retains only remnants of the?

A

embryonic notochord

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7
Q

Develops into the central nervous system in the adult stage.

A

Dorsal, Hollow Nerve Cord

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8
Q

The nerve cord of a chordate embryo develops from a _________ that rolls into a _________ to the notochord

A

plate of ectoderm
tube dorsal

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9
Q

In most chordates,__________ develop into slits that open to the outside of the body.

A

pharyngeal clefts

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10
Q

Functions of pharyngeal slits:

A

Suspension-feeding structures in many invertebrate chordates

Gas exchange in vertebrates (except vertebrates with limbs, the tetrapods)

Develop into parts of the ear, head, and neck in tetrapods

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11
Q

Chordates have a tail at what location to the anus?

A

posterior

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12
Q

In many species of chordates, the tail is greatly reduced during?

A

embryonic development

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13
Q

The chordate tail of chordates contains what?

A

skeletal elements and muscles

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14
Q

It provides propelling force in many aquatic species

A

Muscular, Post-Anal Tail

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15
Q

Early Chordate Evolution:
Ancestral chordates may have resembled?

A

lancelets

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16
Q

Are named for their bladelike shape

A

Lancelets

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17
Q

Marine suspension feeders. They retain characteristics of the chordate body plan as adults

A

Lancelets

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18
Q

Genome sequencing of tunicates has identified genes shared by?

A

tunicates and vertebrates

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19
Q

__________ in lancelets holds clues to the evolution of the vertebrate form

A

Gene expression

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20
Q

Organisms more closely related to other chordates than lancelets

A

Tunicates

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21
Q

Other name for tunicates

A

(Urochordata)

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22
Q

Tunicates are marine suspension feeders commonly known as?

A

sea squirts

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23
Q

At what stage does tunicate draws in water through an incurrent siphon to filter food particles?

A

Adult stage

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24
Q

Tunicates most resemble chordates during what stage?, which may last only a few minutes

A

larval stage

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25
Q

These control the development of major regions of the vertebrate brain.

A

Hox Genes

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26
Q

The period where an immense variety of invertebrate animals inhabited Earth’s oceans.

A

Early Cambrian period(some 530 MYA)

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27
Q

Early Chordate Evolution:
Predators used ______ and ________ to skewer their prey.

A

sharp claws and mandibles

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28
Q

Early Chordate Evolution:
Give two main features. One of which enabled their bearers to filter food from the water

A

protective spikes or armour as well as modified mouthparts

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29
Q

This genus had ear capsules and eye capsules, parts of the skull that surround these organs

A

Myllokunmingia

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30
Q

paleontologists have identified Myllokunmingia as?

A

true craniate.

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31
Q

3 features of Myllokunmingia that made them true craniates

A

Ear capsule
eye capsule
parts of the skull

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32
Q

Research on _______ has also revealed important clues about the
evolution of the chordate brain.

A

lancelets

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33
Q

Lancelets have only a slightly _______ on the anterior end of their dorsal nerve cord

A

swollen tip

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34
Q

Their genome has been completely sequenced and can be used to identify genes likely to have been present in early chordates.

A

Tunicates

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35
Q

State three Hox genes and the major regions they control.

A

BF1 Otx and Hox3: Forebrain, Midbrain and Hindbrain

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36
Q

Craniates have how many clusters of Hox genes?

A

2

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37
Q

Lancelets and tunicates have how many cluster of hox genes?

A

1

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38
Q

A collection of cells near the dorsal margins of the closing neural tube in an embryo

A

Neural crest

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39
Q

Neural crest cells give rise to?

A

some of the
bones and cartilages of the skull.

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40
Q

In aquatic craniates, pharyngeal clefts evolved into?

A

gill slits

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41
Q

Compare Craniates to tunicates and lancelets

A

Has higher metabolism and are more muscular

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42
Q

At what year did paleontologists who were working in China discovered a vast supply of fossils of early chordates that
appear to straddle the transition to craniates?

A

1990s

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43
Q

Craniate fossils were formed during?, when many groups of animals were diversifying

A

cambrian explosion

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44
Q

Most primitive of the fossils are the 3-cm-long
_________.

A

Haikouella

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45
Q

Its mouth structure indicates that, like lancelets, it probably was a?

A

suspension feeder

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46
Q

Craniates: chordates with a head
The origin of a head opened up a completely new way of feeding…

A

Active Predation

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47
Q

Craniates share some characteristics: state four.

A

skull
brain
eyes
other sensory organs

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48
Q

What is one feature unique to craniates?

A

Neural crest

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49
Q

Gives rise to a variety of structures, including some of the bones and cartilage of the skull.

A

Neural Crest Cells

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50
Q

Skull bones and cartilage are derived from?

A

Neural crest Cells

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51
Q

What allowed some vertebrates to colonize the land?

A

Evolution of Limbs

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52
Q

more than 150MYA, vertebrates were restricted to the?

A

ocean

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53
Q

Approximately _____ species of vertebrates

A

52,000

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54
Q

In the vast oceans were the biggest animal ever to exist on Earth. Which is?

A

blue whale,

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55
Q

The period where a lineage of craniates evolved into vertebrates

A

Cambrian period

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56
Q

Vertebrates are craniates that have a?

A

backbone

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57
Q

Cambrian period
True or False
Vertebrates became more efficient at capturing food and avoiding being eaten.

A

True

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58
Q

The least derived surviving craniate lineage is?

A

Myxini, the hagfishes

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59
Q

Have a cartilaginous skull and axial rod of cartilage derived from the notochord, but lack jaws and vertebrae.

A

Myxini, the hagfishes

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60
Q

Organism with small brain, eyes, ears, and a nasal opening that connects with the pharynx

A

Myxini, the hagfishes

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61
Q

Myxini mouths contain tooth-like formations
made of?

A

keratin

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62
Q

Vertebrates have the following derived characters:

A

Vertebrae enclosing a spinal cord

An elaborate skull

Fin rays, in the aquatic forms

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63
Q

After vertebrates branched off from other craniates, they underwent another gene duplication transcription factor genes known as?

A

the Dlx family

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64
Q

Are little more than small prongs of cartilage arrayed dorsally along the notochord.

A

Vertebrae

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65
Q

Aquatic vertebrates also acquired dorsal, ventral, and anal fins stiffened by bony structures known as?

A

fin rays

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65
Q

Aquatic vertebrates also acquired dorsal, ventral, and anal fins stiffened by bony structures known as?

A

fin rays

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66
Q

The function of fin rays,

A

Provide thrust and steering control when swimming

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67
Q

Represent the oldest living lineage of vertebrates

A

Lampreys (Petromyzontida)

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68
Q

Jawless vertebrates inhabiting various
marine and freshwater habitats

A

Lampreys (Petromyzontida)

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69
Q

Lampreys (Petromyzontida) have ______surrounding the notochord and arching partly over the nerve cord

A

cartilaginous segments

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70
Q

Like lampreys, the early members of these lineages lacked THIS FEATURE, but the resemblance stopped there.

A

jaws

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71
Q

Fossils of Early Vertebrates
_______ were extremely abundant for over 300 million years.

A

Conodonts

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72
Q

They have been used for decades by petroleum geologists as guides to the age of rock layers in which they search for oil.

A

fossilized dental elements

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73
Q

Early vertebrates that lived from the late Cambrian until the late Triassic periods.

A

Conodonts

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74
Q

Conodonts are early vertebrates that lived from?

A

late Cambrian until the late Triassic periods

75
Q

Unlike lampreys, conodonts had _________, which they used for either ______

A

mineralized mouthparts
predation or scavenging

76
Q

Were the first vertebrates with mineralized skeletal elements

A

conodonts

77
Q

Vertebrates with additional innovations emerged during the?

A

Ordovician, Silurian, and Devonian periods.

78
Q

Fossils of Early Vertebrates four features. Not the derived characters

A

Paired fins
Inner ear
lacked jaws
muscular pharynx

79
Q

Origins of Bone and Teeth
______ appears to have originated with vertebrate mouthparts

A

Mineralization

80
Q

Origins of Bone and Teeth
The ______ became fully mineralized much later

A

vertebrate endoskeleton`

81
Q

Named for their jaws, hinged structures that, especially with the help of teeth

A

Gnathostomes

82
Q

According to one hypothesis:
 gnathostome jaws evolved by modification of the _____ that had previously supported the anterior pharyngeal (gill) slits
 The remaining gill slits remained as the major sites of respiratory gas exchange with the external environment.

A

skeletal rods

83
Q

Hypothesis for the evolution of vertebrate jaws.
The skeleton of the jaws and their supports may have evolved from two pairs of ______ (red and green) located between gill slits near the mouth.

A

skeletal rods

84
Q

Derived Characters of Gnathostomes
-Common ancestors of all gnathostomes underwent an additional duplication of ____, such that the single set present in early chordates became _____

-Their ____ is enlarged compared to that of other craniates, mainly associated with enhanced senses of _______

A

Hox genes, four

forebrain; smell and vision

85
Q

Derived Characters of Gnathostomes
* Aquatic gnathostomes have a?
 organs that form a row along each side of the body
 sensitive to vibrations in the surrounding water

A

lateral line system

86
Q

Gnathostomes appeared in the fossil record in the ______ period, about 450MYA, and steadily became more diverse.

A

late Ordovician

87
Q

Evolution of the Gnathostomes:
Most _______ were less than a meter long, though some giant ones measured more than 10 m

A

placoderms

88
Q

Collective term for other groups of jawed vertebrates

A

Acanthodians

89
Q

Evolution of the Gnathostomes, by 420MYA, they had diverged into
the three lineages of jawed vertebrates that survive today:

A

Chondrichthyans, ray-finned fishes, and lobe-fins.

90
Q

Today, jawed vertebrates, or gnathostomes, outnumber jawless
vertebrates

Gnathostomes have jaws that might have evolved from?

A

skeletal supports of the pharyngeal slits

91
Q

Have a skeleton composed primarily of cartilage

A

Chondrichthyans

92
Q

Chondrichthyans:
The cartilaginous skeleton evolved secondarily from _____

A

an ancestral mineralized skeleton

93
Q

The largest and most diverse group of chondrichthyans includes the?

A

sharks, rays, and skates

94
Q

–have a streamlined body and are swift swimmers
– carnivores
– have acute senses
–have a short digestive tract; a ridge called the _____ increases the
digestive surface area

A

Sharks

spiral valve

95
Q
  • Shark eggs are fertilized internally but embryos can develop in different ways:

_____: eggs hatch outside the mother’s body

_____: the embryo develops within the uterus and is nourished by the egg yolk

_____: the embryo develops within the uterus and is nourished through a yolk sac placenta from the mother’s blood

A

Oviparous
Ovoviviparous
Viviparous

96
Q

Vast majority of vertebrates belong to a clade of gnathostomes known as Class?

A

Osteichthyes

97
Q

This class includes the bony fish and tetrapods

A

Class Osteichthyes

97
Q

Informally known as the fishes

A

Aquatic osteichthyans

98
Q

Fishes control their buoyancy with an air sac known as?

A

swim bladder

99
Q

Are gnathostomes that have limbs

A

Tetrapods

100
Q

Tetrapods have some specific adaptations:

A

– Four limbs, and feet with digits
– Ears for detecting airborne sounds

101
Q

The most significant character of tetrapods gives the group its
name, which means “_____” in Greek.

A

four feet

102
Q

Terrestrial life brought numerous other changes to the tetrapod body plan.

A

 head is separated from the body by a neck
 originally had one vertebra on which the skull could move up and down.
 origin of a second vertebra in the neck, allowed the head to swing from side to side

103
Q

Terrestrial life

Bones of the ____ are fused to the _____

A

pelvic girdle, backbone

104
Q

True or False
Adults of living tetrapods do not have gills

A

True

105
Q

Except for some fully aquatic species:
During embryonic development, the _____ instead give rise to parts of the ears, certain glands, and other structures

A

pharyngeal clefts

106
Q

The ______ were home to a wide range of lobe-fins.

A

Devonian coastal wetlands

107
Q

Tetrapods that entered particularly shallow, oxygen-poor water could use their _____ to breathe air.

A

lungs

108
Q

The tetrapod body plan did not evolve “out of nowhere” but was simply a ______of a pre-existing body plan.

A

modification

109
Q

The Origin of Tetrapods
Recent discovery of a fossil known as ____ has provided new details on how this process occurred

A

Tiktaalik

110
Q

Unlike a fish, Tiktaalik had a full set of ____ that would have helped it breathe air and support its body.

A

ribs

111
Q

Tiktaalik had _____, allowing it to move its head about unlike fishes.

A

neck and shoulders

112
Q

Fish characters vs Tetrapod characters

A

Fish: Scales, Fins, Gills, and lungs

Tetrapods: Neck, Ribs, Fin skeleton, Flat skull. eyes on top of skull

113
Q

Are tetrapods that have a terrestrially adapted egg

A

Amniotes

114
Q

Are a group of tetrapods whose living members are the reptiles, including birds, and mammals

A

Amniotes

115
Q

The amphibians (class Amphibia) are represented today by about 6,150 species of?

A

 salamanders(Order Urodela, “tailed ones”)
 frogs (Order Anura, “tail-less ones”)
 caecilians (Order Apoda, “legless ones”).

116
Q

_____ is common among aquatic salamanders; the axolotl, for instance, retains larval features even when it is sexually mature

A

Paedomorphosis

117
Q

Amniotes are named for the major derived character of the clade, the amniotic egg, which contains four specialized membranes:

A

– amnion
– chorion
– yolk sac
– allantois

118
Q

Is a disposal sac for certain metabolic wastes produced by the embryo

A

Allantois

119
Q

It protects the embryo in a fluid-filled cavity that cushions against mechanical shocks

A

Amnion

120
Q

It enables the exchange of gas between the embryo and the air

A

Chorion

121
Q

It contains a stockpile of nutrients that feed ths embryo

A

Yolk sac

122
Q

Reptiles have scales that contain?

A

the protein keratin

123
Q

Reptiles are_____, which means that they absorb external heat as their main source of body heat, however the reptile clade is not entirely ectothermic;

A

ectothermic

124
Q

Birds are _____, capable of maintaining body temperature through metabolic activity.

A

endothermic

125
Q

As reptiles diverged from their lizard- like ancestors, one of the first major groups to emerge were?

A

parareptiles

126
Q

Mostly large, stocky, quadrupedal herbivores

A

parareptiles

127
Q

Parareptiles died out by about 200MYA, at the end of the _____ period.

A

Triassic

128
Q

As parareptiles were dwindling, another ancient clade of reptiles, the _____, was diversifying.

A

diapsids

129
Q

Derived characters of the diapsids:

A

a pair of holes on each side of the skull, behind the eye socket
muscles pass through these holes and attach to the jaw, controlling jaw movement

130
Q

Two lineages of the diapsids:

A

Lepidosaurs
Archosaurs,

131
Q

This lineage also produced a number of marine reptiles, including the giant mososaurs.

A

Lepidosaurs,

132
Q

Some of these marine species rivaled today’s whales in length; all of them are extinct

A

Lepidosaurs,

133
Q

Lineage that produced the crocodilians, pterosaurs, and dinosaurs

A

Archosaurs,

134
Q

 originated in the late Triassic,

 were the first tetrapods to exhibit flapping flight

 The wing was completely different from the wings of birds and bats.

 It consisted of a collagen-strengthened membrane that stretched between the trunk or hind leg and a very long digit on the foreleg.

A

Pterosaurs

135
Q

Well-preserved fossils show evidence of muscles, blood vessels, and nerves in the wing membranes, suggesting that _____ could dynamically adjust their membranes to assist their flight.

A

pterosaurs

136
Q

pterosaurs had become extinct when?

A

end of the Cretaceous period 65MYA

137
Q

Three lineages of dinosaurs:

A

*Ornithischians,
*Saurischians,
*Theropods,

138
Q

Were herbivores; they included many species with elaborate defenses against predators, such as tail clubs and horned crests.

A

*Ornithischians,

139
Q

Included the long-necked reptiles

A

*Saurischians,

140
Q

which were bipedal carnivores.

Included the famous Tyrannosaurus rex as well as the ancestors of birds.

A

*Theropods,

141
Q

represented by two species of lizard- like reptiles known as tuataras
These organisms thrived on many continents well into the Cretaceous period, reaching up to a meter in length.

A

Lepidosaurs

142
Q

Are found only on 30 islands off the coast of New Zealand.

A

tuataras

143
Q

The other major living lineage of lepidosaurs consists of the lizards and snakes,

A

squamates,

144
Q

are the most numerous and diverse reptiles alive today.

A

Lizards

145
Q

are legless lepidosaurs that descended from lizards.

A

Snakes

146
Q

Today, some species of snakes retain______, providing evidence of their ancestry.

A

vestigial pelvic and limb bones

147
Q

Have a boxlike shell made of upper and lower shields that are fused to the vertebrae, clavicles (collarbones), and ribs.

A

Turtles

148
Q

Alligators and Crocodiles are collectively known as?

A

crocodilians

149
Q

Alligators and Crocodiles belong to a lineage that reaches back to the _____

A

Late Triassic period

150
Q

Grew as long as 12 m and may have attacked dinosaurs and other prey at the water’s edge.

A

Mesozoic crocodilians

151
Q

Like crocodilians, birds are _____, but almost every feature of their anatomy has been modified in their adaptation to flight.

A

archosaurs

152
Q

Birds lack a_____, and the females of most species have only one ______.

A

urinary bladder,
ovary

153
Q

Derived Characters of Birds,
The _____ of both females and males are usually small, except during the breeding season, when they increase in size.

A

gonads

154
Q

Living birds are also _____, an adaptation that trims the weight of the head.

A

toothless

155
Q

Chinese paleontologists have unearthed a spectacular trove of feathered _____ that are shedding light on the origin of birds

A

theropod fossils

155
Q

Cladistic analyses of birds and reptilian fossilsindicate that birds belong to the?

A

theropods

156
Q

Which was discovered in a German limestone quarry in 1861, remains the earliest known bird (Figure 34.31).

A

Archaeopteryx,

157
Q

By 150 MYA,__________ had evolved into birds

A

feathered theropods

158
Q

The clade that includes the 28 orders of living birds, can be found before the Cretaceous-Paleogene boundary 65.5MYA.

A

Neornithes,

159
Q

The _____, which consist of the ostrich, rhea, kiwi, cassowary, and emu, are all flightless

A

ratites

160
Q

a distinctive character of mammals

A

Presence of mammary glands

161
Q

Derived Characters of Mammals:

A
  • Presence of mammary glands  a distinctive character of mammals
  • presence of hair (fur) and a fat layer under the skin help the body retain heat
  • generally have a larger brain than other vertebrates of equivalent size
  • relatively long duration of parental care
  • differentiated teeth
162
Q

The three smallest bones of present-day mammals

A

Stapes
Incus
Malleus

163
Q

Mammals belong to a group of amniotes known as

A

synapsids.

164
Q

distinctive characteristic of synapsids

A

temporal fenestra

165
Q

Evolved into large herbivores and carnivores and for a time they were the dominant tetrapods.

A

Synapsids

166
Q

Events that gave a heavy toll on the synapsids

A

Permian-Triassic extinctions

167
Q

Period when synapsid diversity fell

A

Triassic Period(251-200MYA)

168
Q

Event when mammal-like synapsids emerged

While not true mammals, these synapsids had acquired a number of the derived characters that distinguish mammals from other amniotes.

A

End of the Triassic Period

169
Q

Period when the first true mammals arose and diversified into many short-lived lineages

A

Jurassic (200–145MYA)

170
Q

Periods where A diverse set of mammal species which measured less than 1m coexisted with dinosaurs

A

Jurassic and Cretaceous periods

171
Q

When did the three major lineages of mammals emerge? State the three lineages

A
  • – monotremes (egg-laying mammals)
  • –marsupials (mammals with a pouch)
  • –eutherians (placental mammals)
172
Q

Period when extinction of large dinosaurs, pterosaurs and marine reptiles happen

A

late Cretaceous period

173
Q

In late Cretaceous period, Mammals underwent an _______, giving rise to large predators and herbivores as well as flying and aquatic species.

A

adaptive radiation

174
Q

 found only in Australia and New Guinea
 represented by one species of platypus and four species of echidnas (spiny anteaters)
 lay eggs, a character that is ancestral for amniotes and retained in most reptiles
 have hair and produce milk, but they lack nipples
 Milk is secreted by glands on the belly of the mother.
 After hatching, the baby sucks the milk from the mother’s fur.

A

Monotremes

175
Q

 lining of the uterus and the extra embryonic membranes that arise from the embryo
a structure in which nutrients diffuse into the embryo from the mother’s blood

A

Placenta

176
Q

Include opossums, kangaroos and koalas

Both marsupials and eutherians share derived characters not found among monotremes.

They give birth to live young.

The embryo develops inside the uterus of the female’s reproductive tract.

A

Marsupials(mammals with pouch)

177
Q

In most marsuppial species, the nursing young are held within a maternal pouch known as

A

marsupium.

178
Q

During this era, Marsupials existed worldwide, however, are found in Australia and North and South America today.

A

Mesozoic era

179
Q

Mesozoic era
* After the breakup of the supercontinent _____, South America and Australia became island continents, and their marsupials diversified in isolation from the eutherians that began an adaptive radiation on the northern continents.

A

Pangaea

180
Q

Early Evolution of Mammals
* Australia
 _______ has resulted in a diversity of marsupials that resemble eutherians in similar ecological roles in other parts of the world

A

convergent evolution

181
Q

Early Evolution of Mammals
* South america
 diverse marsupial fauna throughout the _______
 it has experienced several immigrations of eutherians

A

Paleogene

182
Q

About _______ MYA
 North and South America joined at the ______and extensive two- way traffic of animals took place over the land bridge

A

3 MYA
Panamanian isthmus

183
Q

Commonly known as placental mammals because their placentas are more complex

A

Eutherians (Placental Mammals)

Evolutionary Biology (6 decks)

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