Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Vertebrates > Evidence of Vertebrate Life > Flashcards

Evidence of Vertebrate Life Flashcards

1
Q

What is our closest non chordate relative

A

Sea star

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Does carbon dating date the fossil itself?

A

No, dates rocks around it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Oldest living vertebrates

A

Cyclostomata (round mouth)

Lamprey and hagfishes (jawless fishes=Agnatha)

Have rudimentary vertebrae made of cartilage, not bone. Vertebrae only in embryo in hagfish.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Tetrapods

What is important about their limb bones

A

Vertebrate with four limbs or- like snakes, birds and whales are descended from vertebrate with four limbs

Limb bones of tetrapods are HOMOLOGOUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ray-finned fishes represent _____ of all fished today

A

95%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Coelacanth

A

Lobe-finned fish

Only 8 species live today

Our closest relative among fish

Have humerus!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

We last shared a common ancestor with coelacanth _____

A

400mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Intermediate fossils of Tiktaalik

A

Lobe-finned fish (Eusthenopteron)
-385mya

Early tetrapod (acanthostega)
-365 mya

Between fish and tetrapod was needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How to look for a specific fossil

A
  1. Use distribution of known fossils to determine when there was a gap in the fossil record
  2. Predict where rocks of that age (375mya) are exposed on earths surface
    -type of rock
    -age of Rock
    -location of rock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Narrow range of conditions needed for a fossil to form

A

-most are consumed, trampled or beaten by weather that nothing is left to fossilize
-soft tissue organism are unlikely to fossilize
-fossil record can never be complete
-have to die in the right place (stream, lake or muddy area)
-fossils usually form when an organism is immediately cover by water (create sedimentary rocks)
-fossils in sedimentary rock are quickly worn away when exposed to the surface (sun, wind, rain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What percent of dinosaur species is estimated to be known

A

<1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Type of rock with most fossils

A

Sedimentary

High temp of igneous and pressures of metamorphic destroy animal remains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Radiometeic dating: carbon dating

A

Carbon dating can be used to directly date fossils or sedimentary rock
-carbon daring only works for fossils and rock less than -50,000years (carbon decays quickly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Other radiometric dating isotopes

A

Potassium-argon 50,000-4.6Bya
Uranium-lead: 10m-4.6b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How palaeontologists predict where to find fossils

A
  1. Type of rock: sedimentary
  2. Age of rock: geological layer (time)
    3.Location of rock exposed on Earths surface: disconnect between past and present (changing lane forms: mountains rise, erode). Need rock exposed on the planets surface, continental drift
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ellesmere Island and continental drift

A

365 mya during the Devonian period, island was on equator. Now it is 80.7°N

Home of Tiktaalik

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Tiktaalik fish and tetrapod features

A

Large freshwater fish

Fish: scales, fills, delicate ray-finned tail

Tetrapod: flat head, eyes on top, neck moves (head free of shoulders), two wrist bones (Ulnare and intermedium) enable it to do a push up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does Tiktaalik tell us about why limbs evolved

A

Anatomical features suggest Tiktaalik lived in water: gills, rays on tail, paddle shaped limbs probably used to pull itself along the shallow water.

Infer: bones that later formed a limb originated for life in water, not because they were useful to animals that already lived on land.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cambrian explosion

A

541-515mya
-Sudden diversification of life early in the Cambrian

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Pre Cambrian includes which eons

A

Archean and proterozoic eons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hadean Eon

A

4.6bya to 4.0bya
-water present (4.0)
-earth forms; collisions with debris in solar system (4-3.8)

Volcanic eruptions, frequent collisions with other solar system bodies, extreme heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Archean Eon

A

4.0-2.5bya
-single celled organism arise
-earth crust cooled
-prokaryotes only
-stromatolites, thermal microorganism
-oldest known bio markers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Stromatolites and when they appeared

A

Microbial mats; layers of Cyanobacteria and sediments.
-single celled but colonial
-first form of life visible to naked eye
-appeared in archean Eon 3.5bya

-prokaryotes we’re earths sole inhabitants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Deep sea thermal vent microorganisms date back to

A

3.8bya
-tubular microfossils

Archean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Bio markers

When are earliest found

A

Molecules produced by biological processes
Ex: DNA traces, lipids, carbon isotopes, oxygen, methane

3.7bya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When was an increase in oxygen found

A

Ancient rocks show sudden rise in O2 at 2.6by probably result of photosynthesis by Cyanobacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Proterozoic Eon

A

“Earlier life”
2.5bya-541mya (Cambrian)

-life in ocean dominated by microbes (free floating bacteria, hydrothermal vent single celled organisms, microbial mats)
-photosynthetic eukaryotes (algae) at oceans surface (1.6bya)

Eukaryotes arrive!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Eukaryotes

A

Nucleus surrounded by a membrane

Plants, animals, fungi and protists (single celled eukaryotes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Toward the end of the Proterozoic eon, we see fossils of ______ and ______

A

Sponges and cnidarians (jellyfish)

Sponges are earliest evidence of animals (650mya)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When was the oldest evidence of animal tracks found (eon)

A

Proterozoic

585mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Ediacaran period

A

635-541mya

First explosion of complex life
-invertebrates (probably)
-most were sedentary
-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Cambrian period
-eon
-date
-purpose
-explosion timeline

A

Phanerozoic eon
541-485mya
-moving animals, predators, decrease in ediacaran species

541mya -new life forms that we recognize today

When most of the phyla of animals that are still alive today appear! Include us the chordates!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Phanerozoic Eon

A

Visible life

541 mya-present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

4 Eons

A

Hadean
Archean
Proterozoic
Phanerozoic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Animals that appeared during the Cambrian had a body plan similar to that of many invertebrates and vertebrates living today… including…

A

Bilateral symmetry
Heads and tails
Segmentation
Mobility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

The first major excavation site for the Cambrian fauna was at…..

A

Burgess Shale, BC (Rockies)

Sea bed pushed upwards into mountains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Possible reasons for Cambrian explosion

A

-genetic revolution and movement (HOX)
-increase O2 permitted animals to be bigger
-arms race (predator-prey)
-increased nutrients due to sea level rise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Colonization of lane over time

Step by step

A

1bya-Cyanobacteria and photosynthetic prokaryotes in damp terrestrial locations

500mya-fungi, moss-like plants

450mya-arthropods were the first animal group

365mya-early tetrapods (first vertebrates on land

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

3 eras in the Phanerozoic era

A

Paleozoic
Mesozoic
Cenozoic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Paleozoic era

A

-cambrian explosion
-chordates and vertebrates appear
-Devonian: vertebrates move to land
-Permian mass extinction (252mya)

541mya-252mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Mesozoic era

A

-k-pg mass extinction: 65.5mya, dinosaurs die (except birds)
-mammals live in shadows of dinosaurs

252-65.5mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Cenozoic era

A

Recent

Mammals diversify

65.5mya-present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Mass extinctions

A

Catastrophes that influenced vertebrate evolution

Eliminate certain groups
Enable other groups to survive and diversify

5 identified since start of the Cambrian

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

End of Devonian extinctions

Extinction led to explosion of which groups

A

Two extinctions near the end of the Devonian (Paleozoic)
-last extinction eliminated 44% of jawed vertebrates, many lobed-finned fishes, and most of initial tetrapods

Expansion of ray-finned fishes and cartilaginous fishes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Permian extinction

A

Eliminated the largest proportion of species of any extinction to date. Referred to as “the day when life nearly died”

-during the last period of the Paleozoic era, with the Triassic periods of the Mesozoic era beginning. (252my)
-eliminated 57% of marine invertebrates (trilobites too), 95% of Marine vertebrates.
-massive volcanic activity led to runaway greenhouse gas effect with global warming and ocean acidification

Took 5 million years to recover

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

After recovery from the Permian extinction, what group took over

A

Dinosaurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

K-pg (KT) extinction

Cretaceous-Paleogene extinction

A

During end of Cretaceous period (end of Mesozoic era)
-most famous extinction
-large asteroid hitting earth (Yucatan peninsula)

-extinguished all non-again dinosaurs and other large vertebrates
-volcanic activity contributed

65.5mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Following the K-pg extinction, what group took over

A

Mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Are we in the middle of the 6th mass extinction?

A

-habitat loss
-over hunting
-pollution
-increase co2 and green house gases
-ocean chemistry

Most current vertebrates are above the background extinction rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Anthropocene

A

Present world

How humans have altered the world

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Chordates share which important aspects of their body plan with bilateral invertebrates (clade Bilateria)

A

Bilateral symmetry
Anterior-posterior axis
Cephalization (anterior head, posterior anus)
Mobility
3 germ layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Types of symmetry

A

-asymmetry (sponges)
-spherical symmetry (divide body in equal halves by any cut through center)
- radial symmetry (symmetry around central axis-hydras, jellyfish)
-bilateral symmetry (Sagittal cut makes mirror image-buts, fish)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

LCA

A

Last common ancestor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

When did the bilaterians arrive

A

600mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Bilaterians have ____ germ layers

This means they are called ______

A

3

Triploblastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Coelom

A

Body cavity within mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Do flatworms, nematodes, mollusks or annelids start the coelom

A

Nematodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Which groups have a true coelom

Do molluscs count?

A

Annelids, arthropods, chordates

No, reduced coelom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What groups of metazoa are deuterostomes

A

Chordates
Echinoderms

60
Q

Gastrulation

A
  1. Formation of the gut
  2. Also used to describe formation of germ layers
    -cells from outer layer (ectoderm) move inward to form endoderm (inner layer)
61
Q

Diploblastic animals have how many germ layers

A

2

62
Q

What does deuterostomes and protostomes mean

A

Mouth second (first opening formed during Gastrulation is the anus.

Mouth first

63
Q

Mesoderm

A

-Third germ layer to arise in Triploblastic
-middle layer
-arises from endoderm
-once formed, a new cavity arises from it (coelom)-fluid filled cavity lying within the mesoderm.

64
Q

At 4 weeks of conception, we have a ____ within a _____ with three germ layers that give rise to ______

A

Tube (gut)

Tube (coelom)

All our organs

65
Q

Chordates and most bilateral invertebrates (annelids, arthropods, echinoderms and Hemichordates) have ______ germ layers and a _____

A

3
Coelom

66
Q

Coelom def

The coelom divides into which 3 body cavities

A

Fluid filled cavity lined by mesoderm on either side

-pleural cavity (encloses lungs)
-pericardial cavity (heart)
-peritoneal cavity (organs within abdomen: intestines, liver)

67
Q

Advantages of having a coelom

A

Space for organs to grow and fallibility in their arrangement

Fluid filled cavities cushion organs which help to prevent injury

68
Q

Endoderm
Mesoderm
Ectoderm

Main differentiated tissues of each

A

-Lung or hill linings
-most of the digestive tract

-bone, cartilage, muscles, circulatory, Urogenital systems (gonads, blood)

-skin cells of epidermis
-pigment cells (neural crest)
-most of the nervous systems
-antihero and posterior digestive tract (mouth and anus)

69
Q

Embryonic cells unique to vertebrates that is considered a 4th germ layer?

A

Neural crest cells!

Forms from ectoderm, lateral to neural tube; separates after nerve tube forms

Considered 4th germ layer

Gave rise to structures unique to vertebrates: certain bones and cartilage of face and skull, adrenal gland, pigment cells, para-and sympathetic nervous systems

70
Q

What is another embryonic tissue unique to vertebrates?

A

Placodes

-form from ectoderm and migrate elsewhere in the body
-give rise to sensory and cutaneous structures (eyes, nose, ears, hair, teeth, feathers, anterior pituitary)

71
Q

Segmentation or metamerism and example

A

The body being constructed in a linear series of relating parts, each formed in a sequence in the embryo, from anterior to posterior

Vertebrate development

Myomeres, ribs, vertebrae

72
Q

Metamerism is a shared characteristic with animals that have a _____

A

True coelom (annelids and arthropods)

73
Q

Somites

A

Developing segment (in embryo)

-develop from mesoderm in the embryo along anterior-posterior axis

Segmented (somatic) mesoderm forms structures that are repeated (axial skeleton and axial muscle)

74
Q

Mesoderm that is not segmented, forms structures that are ______

A

Not repeated

75
Q

Metamere

A

One segment of repeated body segments in animals or plants

76
Q

Annelids, arthropods and chordates have bilateral characterisitcs as well as

A

A true coelom

Matemerism

77
Q

In what stage do embryos have the defining features of chordates

A

Pharyngula or phylotypic (pharyngeal pouches visible)

Shared feature develop early
Derived features develop later

78
Q

Mangold-Spermann experiment

A

Two salamander eggs in Gastrulation stage. One egg has piece of dorsal lip (ectoderm invades endoerderm) taken and put onto another egg. Second egg develops a second embryo at the site of transplant, consisting of the donor and recipient cells (different pigments)

Conclusion: a cells fate is not predetermined at the time of fertilization

79
Q

Old view of genes

A

Each gene has a specific trait it determines such as an arm or eye

Therefore organisms that are more complex should have more genes

80
Q

Human chromosomes and protein coding genes

A

3600 genes are continually expressed in all cells as basic cellular process genes

14200 genes required in some tissue at certain times though not others

81
Q

New understanding of genes

A

Gene-regulatory networks
-expression of a few genes triggering or inhibiting the expression of downstream genes or molecules

82
Q

Genes that regulate development are known as

A

Homeotic genes or developmental regulatory genes

83
Q

_______ genes and other ___________ interact in hierarchical networks that shape the geography of developing animals

A

Hox

Developmental regulatory genes

84
Q

First homeotic gene to be discovered

A

Hox

85
Q

Homeotic transformations in fruit flies are caused by defects in ______

A

Single genes

86
Q

Ed Lewis gene hypothesis and explanation

A

Single gene determines the type of Boyd segment (true)

Every cell in an organism Carrie’s, within its DNA, all of the information necessary to build the entire organism, but not all the info is expressed in every cell.

87
Q

Antp (Hox gene) expressed where causes what

A

Expressed in thoracic area causes legs to grow at right palce

Expressed on head causes legs to grow in place of antenna

88
Q

Genes are position on the chromosome in the order that……

A

They correspond on the final body plan

89
Q

Hox genes either ______ or ______ downstream genes

A

Allow
Suppress

If hox gene Antp is activated in the head, genes coding for antenna are suppressed but the gene Distalless is expressed causing a leg

90
Q

Hox genes are arranged along the chromosome in the same_______

A

Spatial and temporal order in which they are expressed

91
Q

How many hox genes and chromosome do mammals and fruit flies have

A

39 Hox genes on 4 chromosome (paralog genes of mammals from duplication events)

8 Hox genes on 1 chromosome

Hox genes are homologous to both!!!

92
Q

Why will Hox genes in flies be expressed but rarely in mammals

A

Has 1 copy

Has many copies (paralogs) of same Hox genes that can overrule the mutation

93
Q

Spatial and temporal sequence of Hox genes in a mouse embryo

A

First, anterior hox gene is expressed which corresponds to the neck (cervical)

Then, another hox gene is expressed that corresponds to throrax

Finally, another hox gene is expressed and corresponds to lumbar vertebrae

94
Q

Duplication and loss events

A

Duplication of Hox genes in vertebrates

Fish have huge amount is genes but fewer chromosomes suggesting a less of clusters

95
Q

Are Hox genes only in vertebrates?

A

No

Plants and jellyfish (invertebrates) too

96
Q

Eyeless gene and major breakthrough

A

Fruit fly grew a normal fruit fly rye from a mouse “eyeless gene”

Same genes!!!! Universal set of genes!!

97
Q

Chordates have more hox genes in what area compared to flies?

A

Lumbar

98
Q

Ortholog

A

A homologous gene in different taxa

99
Q

Mouse Pax6 initiates formation of _____ on fruit fly, on any body segment where it is expressed

Pax6 (eyeless) is homologous across _________ and ______

A

Eye

Codes for “eye” not for the specific form of eye

Vertebrates and invertebrates

100
Q

Mouse and fruit fly eyes can develop from either of each species genes, meaning that the genes are ________

A

Homologous

Inherited from a common ancestor

101
Q

Genetic cascade for fruit fly limb

A

Engrailed (En) is at the top of the hierarchy. It defines the posterior part of the limb in flies and in mice.

Hedgehog: in both flies and mice, expression of En turns on a signalling gene called hedgehog in those posterior cells ( the gene is known as sonic hedgehog in terrapods)

Dpp, Wg: Hh protein rhen diffuses into cells that En does not reach. By doing this, a high concentration of Hh causes cels to being expressing two additional signalling genes (Dpp and wingless (Wg))

These genes then initiate one more level of gene activity (D||, EGFR) the combination of these scrabble maps out the geography of the limb in all its dimensions

102
Q

Fruit fly limb genes and mouse limb genes

A

Same cascade, different names due to people not knowing they were the same

En (Engrailed) in both

Hh=Shh

Dpp=Bmp

Dll=Dlx

EFGR=FGFs

103
Q

In tetrapods like mice, limb and digit development is arrested when _____ expression is blocked

A

Sonic hedgehog

Too little Shh=fewer digits

Too much Shh=additional digits

104
Q

Shh turns on at the same location of a ______ and a ______

A

Fin and a limb

105
Q

Shh (Hh) function

A

Left-right body axis; Sitka/proximal limb axis, feather formation, brain development

106
Q

Dlx, Dll (distalless) function

A

Jaws, limbs, colour patterns

107
Q

Pax6 (eyeless) function

A

Eyes, sensory organs, certain neural tissues

108
Q

Bmp (Dpp) function

A

Bone morphogenetic protein: bone formation; cell division and death; dorsal-ventral axis

109
Q

What varies to create diversity in genes

A
  1. Location (Heterotopy): where gene turns on
  2. Timing (Heterochrony): when gene turns on or off, or duration
  3. Level of expression (Heterometry): amount (level of gene expression)
110
Q

How do snakes form the long body

A
  1. Long body: accelerated formation of somites results in >300 vertebrae
  2. Thoracic Hox6 gene expressed over large number of vertebrae, resulting in ribs over a large reason and suppressing fore limb development
    3.Hind legs: limb bud forms but Shh is not expressed, preventing further growth
111
Q

Increased expression of Dpp results in _________

Bmp2 responsible for ________ in bats

A

Long hind limbs of crickets

Long dividers on fore limbs of bats

112
Q

Webbing on duck feet and no webbing on chickens

Genetic traits

A

Cell on distal tip of forelimb produce high levels of Bmp2

Gremlin inhibits loss of webbing between digits in embryo (bat wing, duck foot)

Vertebrates develop fingers and toes with webbing initially. But death of cells removes most webbing.

Genes from bmp family result in the loss of webbing between digit in animals. Gremlin suppresses the loss of webbing between digits in embryo:

113
Q

Dog skull and genes

A

Increased expression of Runx2 increases BMP, which affects length and shape of carnivore skull and snout

114
Q

What genes are important for eyespots on butterfly wings

A

En
Dll
Antp

115
Q

Traditional classification and taxonomy system

A

Linnaean system

Hierarchial system: phylum, class, order, family, genus, species

Binomial nomenclature

116
Q

Phylogenetic systematics or cladistics

A

Produces hypotheses about the evolutionary relationships of organisms in a way that weighs the relative importance of different characteristics

117
Q

Clade

A

Monophyletic group

Evolutionary lineage containing the last common ancestor of all members of the group and all of the ancestors descendants

118
Q

Cladogram

A

A visual representation of the evolutionary history of species, populations or genes

119
Q

Phylogenetic tree

A

Shows the evolutionary history, but also includes data on the evolutionary time scale

120
Q

Cladogram parts
Root
Nodes
Branch
Tip
Time axis

A

Base of the tree

Are points in a phylogeny where a lineage branches (represents a last common ancestor before a speciation event

Lineage evolving through time that connects other branching events

The terminal end of an evolutionary tree (representing) the groups being compared)

Ancestral states (earlier), derived states (more recent)

121
Q

The taxonomic groups included on a cladogram can be switched around, as long as…..

A

They are rotated around a particular node

122
Q

Common misconception about cladograms tips

A

No current living species is ancestral to any other!!!!!

123
Q

Clades are ______ within other clades

A

Nested

124
Q

Apomorphy

A

Derived trait

125
Q

Synapomorphy

Where is it marked

A

Derived character shared by members of a Clade, not found in an “outgroup”

Marked before branch (LCA)

126
Q

Autapomorphy

Where is it marked

A

Derived character unique to one Taxon

Drawn as a line after LCA

127
Q

Examples of vertebrate synapomorphies when compared to amphioxus

A

Skull, expanded Brain and vertebrae

128
Q

Pleisomorphy

Symplesiomorphy

A

Ancestral character

Ancestral character shared by members of a group (character that ancestor/ outgroup had that all other members have too)

129
Q

Outgroup

Ingroup

A

A reference group that is less related to the taxa we are comparing

The organisms you are studying

130
Q

A change in a phylogenic tree can mean what?

A

Gain or loss of a trait

131
Q

Any change from the ancestral species, or from an outgroup, is defined as a _____

A

Derived character

132
Q

Which cladogram do you select?

A

The one with fewest steps/ changes

Principle of parsimony (Occam’s razor)

The simplest hypothesis is the most plausible

133
Q

How do you know which species are more closely related by looking at a phylogenetic tree

A

Two groups that share a last common ancestor more recently are more closely related

134
Q

Clade (Monophyletic group)

A

Contains the last common ancestor of all members of the group and all of that ancestors descendants

135
Q

Paraphyletic group

A

A group of organisms that share a common ancestor, but the group does not include all of the descendants of that ancestor

136
Q

Paraphyletic groups involve what we refer to as _____ and _____ groups

A

Stem: extinct forms that lack some of the derived characters found in a crown group (non-avian ancestors of birds)

Crown: Has deceived characters of extinct species in group; includes extinct species that contained those derived characters, but not the stem group

137
Q

Polypheletic group

A

A group that does not include all ancestors of the species

138
Q

If looking at evolutionary relationships you need:

If looking at a particular group that may include the crown group, you need:

If looking at the origins of a train that occurs in different groups (convergent evolution) you need:

A

Monophyletic

Paraphyletic

Polyphyletic

139
Q

Phylogenetic bracketing

A

Cladograms to test hypotheses

Birds and crocodiles form phylogenetic bracket around dinosaurs

140
Q

Did dinosaurs have parental care?

A

Most likely

  1. Phylogenetic bracketing suggests parental care may be ancestral trait for the Clade including dinosaurs
  2. Fossils
141
Q

Examples of natures imperfections

A

Hernias
Hiccups
Blind spot in the vertebrate eye
Circuitous rout of the recurrent laryngeal nerve

142
Q

Inguinal hernias

A

Most common abdominal hernia and mostly occur in men
-testicles start to develop close to heart, but move to scrotum. Testes travel through a canal-called the inguinal canal to descend into the scrotum.
-after the testicles descend, the opening is supposed to close tightly, but sometimes the muscles that attach to the pelvis leave a weakened area in the body wall.
-if stress is placed here…the weakened spot of the body wall will allow a portion of the intestine to slide through that opening into the scrotum, causing pain and producing a bulge!!!

143
Q

Recurrent laryngeal nerve

A

-inner area larynx and muscles related to swallowing and breathing
-travels from brain along neck down near heart, then to larynx

144
Q

Vagus nerve in fishes

A

Vagus nerve and it’s branching travel directly from brain to gills (along the dorsal artery) to help muscles pump water.

Four branches of the vagus nerve are around the gills

145
Q

4th branch of vagus nerve is called what

A

Recurrent laryngeal nerve

Inner area the larynx and role in swallowing

146
Q

What is odd about the recurrent laryngeal nerve

A

Instead of going straight from the brain to the larynx, it goes all the way to blood vessels that are derived from the 6th arterial arch just like in fish!

The nerve in giraffes is 6 meters long

147
Q

Where does the RLN go in humans

A

From brain to under the aortic arch (blood vessels derived from 6th arterial arch of fish) and back to larynx

Vertebrates (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions