COMPLETE EXAM 2 REVIEW Flashcards
(194 cards)
1
Q
Analogous
A
i.e. convergent
-similarities that are independently evolved are called analogous
NOT used in cladograms
Example: similarity of vertebrate and invertebrate eyes… both have independently arrived at essentially the same solution to the problem of converting EM radiation to neural impulses
2
Q
“Tree Thinking”
A
Darwin thought of life as a tree- described living species at the tips, branches are groups of closely related species, branch points are speciation events
- united by shared ancestry
- completely revolutionized comparative and evolutionary biology
- linked embryology, genetics, medicine, etc.
3
Q
Analysis of Fossils
A
pros: direct
cons: fragmentary, can be hard to interpret
4
Q
phylogenetic analysis
A
- compare similarities of organisms (molecular)
- construct cladograms
5
Q
phylogeny is constructed by…
A
speciation
origin of new characteristics
6
Q
Systematics
A
classification to reflect the phylogeny of organisms
7
Q
cladogram
A
a branching diagram depicting an estimate of the phylogeny
8
Q
clade
A
a grouping that includes a COMMON ANCESTOR and all of the descendants (living & extinct) of that ancestor
9
Q
monophyletic
A
shared derived trait (syapomorphy)
single origin- an ancestral species and all of the descendant species grouped together
implies close relationship
monophyletic groups = clade
10
Q
polyphyletic
A
convergent similarity
- independent origins
- does not imply close relationship
i. e bats and birds
11
Q
Paraphyletic
A
primitive similarity
- single origin
- does not imply close relationship
- e.g. lizards and crocs lack feathers, but so did the ancestor of birds
- paraphyletic groups
- most recent common ancestor but not all of its descendents
12
Q
Goal of Phylogenetic analysis (Cladistic Methods)
A
-monophyletic groups
accurately describe relationships
13
Q
Willi Hennig’s (1950,1966) Two principles for reconstructing phylogeny
A
parsimony
outgrip analysis
14
Q
parsimony
A
the cladogram requiring the fewest evolutionary changes is (usually) preferred (AKA Occam’s Razor)
-uses the simplest explanation for the distribution of characters
15
Q
taxon
A
group of similar and related individuals
16
Q
speciation
A
the origin of new species, is at the focal pint of evolutionary theory
17
Q
microevolution
A
consists of changes in allele frequency in a population over time
18
Q
macroevolution
A
refers to broad patterns of evolutionary change above the species level
19
Q
BSC Concept of species
A
all members have the potential to interbreed under natural conditions and produce viable, fertile offspring
“some” hybridization o.k. as long as it doesn’t occur naturally enough to overwhelm the boundary
20
Q
Limitations of BSC Concept
A
-not always clear who has the “potential” to interbreed
-does not apply to asexual organisms
-can’t be applied to fossils
boundaries are arbitrary- i.e. dog x wolf
how much hybridization is too much?
21
Q
morphological species
A
concept is a practical substitute for BSC- looks at structural features
22
Q
phylogenetic species
A
smallest group on a tree
23
Q
ecological species
A
viewed in terms of niche (function or place of an organism in a given ecosystem)
24
Q
pre zygotic barrier
A
separates species by: preventing formation of a zygote or fertilized egg 1. habitat isolation 2. temporal isolation 3. behavioral isolation 4. mechanical isolation 5. gametic isolation
25
post zygotic barrier
```
separates species by:
preventing development of viable or fertile offspring
1. reduced hybrid viability
2. hybrid infertility
3. hybrid breakdown
```
26
habitat isolation
may occupy the same range and be potentially able to hybridize, but prefer different habitats so never (or rarely) mate.
i.e. maggot fly races
27
temporal isolation
may potentially interbreed, but are "ready" at different times
many plants, animals breed at different times
i.e. apple maggots and hawthorn maggots
frogs
28
behavioral isolation
species may encounter each other, but do not mate because of differences in courtship or other behaviors.
i.e. birds, fire fly bling patterns, bird songs
29
mechanical isolation
e.g. lock and key
-found in many insects and flowers
(different anatomy)
30
gametic isolation
gametes do not recognize each other due to different receptors
31
reduced hybrid viability
hybrid offspring do not develop
do not survive as well
i.e. sticklebacks: benthic V. Limnetics
32
hybrid infertility
i.e. mules, tigons etc.
| They are sterile
33
hybrid break down
1st generation hybrids are fertile, but when they mate, the 2nd generation hybrids are sterile or weak
-common in plants?
34
Allopatirc speciation
physical barrier divides population (vicariance)
i.e. a rise of a mountain range, formation of a river or valley, or changes in sea level
examples:
migration to an island or a new habitat
35
adaptive radiation
evolution of many diversely adapted species from a common ancestor (speciation on islands)
36
populations become different due to...
founder effect at outset (especially if one or both of the new populations are small) through genetic drift
natural selection under different conditions. May result in physical or behavioral differences that inhibit breeding even if contact is restored
37
Recontact of populations:
may reinforce differences acquired in isolation
hybrids gradually cease to form
-may overwhelm differences acquired in isolation
38
reinforcement
hybrid offspring have lower survival, so selection favors assortative mating
39
fusion
large areas of hybridization and highly fit hybrids may fuse the two species back into one
40
sympatric speciation
no physical barrier separating diverging populations
i. e. hawthorn maggots shows fidelity to hawthorn trees
1. Autopolypoidy
2. Allopoloploidy
41
autopolploidy
same species mate
duplication of chromosomes number occurs due to meiosis failure
reproductively isolates offspring from parent population
common in plants
facilitated by ability to self-fertilize
42
Allopoloploidy
hybridization and errors in meiosis lead to polyploid offspring with chromosomes from 2 different species that are FERTILE
i.e. marsh grass= wheat
43
Allopolyploidy in plants
key forces in plant speciation = new species
occupy novel ecological "intermediate niches" from parents
- hybrid vigor
44
"Evolution is a Tinkerer"
evolution takes a character and gives it an unexpected function
i.e. turns a leg into a wing
45
Macroevolutionary patterns
Broad-Scale patterns of change, diversification and extinction in the fossil record
- crossing the big boundaries- origin and consequences of new body plans
46
Anagenesis
patterns of change over time
47
Cladogenesis
patterns of diversification
48
Gradualism
-classic darwin
generally slow, constant change
distinction among fossil species fairly arbitrary
appeal to sketchiness of fossil record to explain gaps
does not claim that all change will be gradual, only that this is a predominant pattern
49
Punctuated equilibrium
emphasizes periods of stasis interspersed with periods of "rapid" change (geologically speaking)
works well with cladistics
emphasizes that most change occurs at speciation
50
stasis
long periods of subtle evolutionary change
51
"living fossils"
lineages that have changed so little for such a long time
| i.e coelacanths
52
What causes Stasis
not always clear
-prob includes
stabilizing selection keeping the species from changing
variable directional selection that keeps the species fluctuating around a mean
genetic/ developmental constraints
- retention of primitive features in the absence of appropriate variation or directional selection
53
mosaic evolution
the evolutionary change of different adaptive components of the phenotype of an organism at different times or at different rates in an evolutionary sequence
54
"rapid" change
origin of a new species and characteristics over a time period that is short relative to the period of stasis
does NOT say that speciation/ changes are instantaneous - merely that they happen too quickly to be generally captured in the fossil record
spending on resolution of fossil record, may still be a million years!
55
What causes rapid diversification
1. environmental change
| 2. ecological opportunity
56
environmental change
"sudden" appearance of every animal phyla within about 50 millions of years
why?
increased O2 levels supporting larger body size
predation
57
ecological opportunity
| extrinsic
- extrinsic factors
provide opportunities to occupy previously unavailable niches - adaptive radiation
examples:
darwin's finches
radiation of mammals after dinosaur extinction... also factor in the explosion of bilateral
58
```
ecological opportunity
(intrinsic)
```
key innovations: characteristics that open up new opportunities
i.e. flowers, wants, etc.
novel characteristics
(tinkering)
59
6 origins of evolutionary novelty
1. exaptation
2. duplication
3. Serial Homology
4. Heterochrony
5. Lateral Gene Transfer
6. Homeotic genes and pattern formation
60
exaptation
evolution is a tinkerer!
flowers are modified leaves
insect wings may have arisen as heat collecting devices
61
duplication
evolution of genes with novel functions:
duplicated genes can evolve different (novel) functions
i.e. globin genes, Pseudogenes
62
Serial Homology
i. e. arthropod libs
- repetitive segments in the same organism
- duplicated limbs/ segments can specialize
63
heterochrony
changes in developmental timing can radically alter the adult appearance of an organism
example pedomorphosis
64
Paedomorphosis
a sexually mature adult retains features that were juvenile structures in its evolutionary ancestors
example: starfish
65
Lateral Gene transfer
horizontal movement of individual genes, organelles or fragments of genomes from one lineage to another
(often in bacteria)
66
homeotic genes
small sets of genes function as developmental master switches
67
homeotic genes and pattern formation
simple developmental/ genetic changes can have major effects
68
Factors influencing the shape of the tree of life:
key innovations and their consequences (wings and flowers)
major transformations
major radiations
69
Does the fossil record show gradualism and punctuated equilibrium?
yes
70
Origin of Life Problems
1. we can't observe, even indirectly the earliest steps
2. even simplest forms of life are very complex
Which, if either, came first
DNA- info storage
OR
Proteins- do work, require info from DNA to be assembled
71
Four BIG steps to life
1. formation of small organic compounds
2. formation of complex polymers
3. formation of liposomes to protect complex polymers (and more)
4. formation of a system of self-replication
72
Formation of small, organic compounds
```
i.e. amino acids, nucleotides, sugars, etc.
How?
Oparin-Haldane Theory
Miller (1953) tested how:
atmosphere, spark
```
73
Oparin Haldane Theory
early atmosphere had little oxygen
early atmosphere was reducing (Lots of CH4, NH3, H2)
this favored reactions forming organic molecules
74
Panspermia Hypothesis
organic material (or actual life itself) from elsewhere
75
Formation of polymers
possible without cellular catalysts? yes.
need to concentrate monomers
need to catalyze reaction inorganically
not a huge obstacle
76
formation of liposomes
"aggregates of abiotically produced molecules"
can spontaneously form
artificial vesicles can be created from phospholipids
77
Protocells
can carry out cell like processes
store energy across membrane
take-up and release "metabolites"
78
Formation of a system of self-replication
information, and a means of replicating it
| may have preceded association with protocols
79
Protein or DNA first?
Niether! it could have been an RNA (enzyme- ribozyme) that could poorly cut nucleic acids
80
Why RNA?
genetic info. stored in DNA.
RNA is created from DNA to put info. into action
RNA can direct creation of proteins (mRNA; tRNA; rRNA)
DNA can't do this
RNA is versatile
81
3 Problems with RNA
1. In the absence of cells, products of ribozyme activity would be shared
2. Self-Replication of large RNA's has not been demonstrated
2. initial formation of RNA
82
History of Life
```
earth forms- 4.6 billion years ago
environment very different
-volcanoes
-meteor impacts
-low amount of oxygen
Life appears "quickly"
-prokaryotes
-How do they metabolize
```
83
Prokaryotes
```
dominant life forms on earth
-10x the biomass of all eukaryotes
10^14 prokaryotic cells in your gut; 10^13 cells make up your body
EXTREME metabolic diversity
the basis for all eukaryotic metabolism
```
84
Changes in Earth's physical environment
-atmospheric oxygen concentration has also changed over time
- The early atmosphere probably had little or no oxygen, until some bacteria evolved photosynthesis (about 2.5 bya)
-the O2 dissolved in water and reacted with iron to form iron oxide, which accumulated in alternating layers of red and dark rock, known as banded iron formations.
earliest evidence of photosynthesis
-O2 also began to accumulate in the atmosphere
-cyanobacteria formed stromatolites which are abundant in the fossil record and are still formed today
o2 released by cyanobacteria allowed evolution of oxidation reactions as the source for ATP synthesis
85
prokaryotes are haploid or diploid?
haploid
86
prokaryotes
```
no nuclear envelope
no membrane bound organelles
circular DNA, with relatively few genes
no mitosis; instead do binary fission
began 3.8 billion years ago
bacteria & Archea
```
87
prokaryotes are mono, poly, or para phyletic?
paraphyletic
88
prokaryotic chromosome
```
small size (relative to Euk.)
extreme diversity
simpler structure
haploid
no sex. no centromere, chromatin, etc.
```
89
prokaryotic plasmids
```
few genes
independent replication & transcription
variable importance for cell growth
antibiotic resistance genes
facilitate lateral gene transfer
```
90
transduction
genes via virus infection
91
conjugation
plasmids from live bacteria
92
transformation
genes from environment such as dead batters/ archaea
93
mechanisms of lateral gene transfer
transduction
conjugation
transformation
94
Why is evolution so rapid in prokaryotes
lateral gene transfer
short generation time
high mutation rates
BUT no independent assortment
95
Requirements of Metabolism
```
1. energy-
phototrophs use light
chemotrophs use chemical compounds
2. carbon-
autotrophs use CO2
heterotrophs use organic compounds they consume
```
96
photoautotrophs
use energy from light and carbon dioxide to create energy
| e.g. plants and some prokaryotes like cyanobacteria
97
chemoautotrophs
energy from inorganic and carbon from carbon dioxide
| e.g. some prokaryotes like archea
98
photoheterotrophs
energy from light, carbon from organic sources i.e. some prokaryotes
99
chemoheterotrophs
energy and carbon from organic sources
| e.g. some prokaryotes & us
100
Origin of Cyanobacteria
increased oxygen levels (eventually)
oxygen is very reactive- breaks bonds
bad news for anaerobic organisms
but allowed the evolution of aerobic respiration
101
methanogens
important decomposers
use H2 to reduce CO2 to methane
archaea
102
halophile
thrives in water 10x as salty as the ocean
| archaea
103
thermophiles
up to 105 degrees C
| archaea
104
acidophiles
archaea
| in pH below 1.0 (battery acid)
105
lytic virus
destroy host cell
| virulent
106
lysogenic
silent in host genome
| can become active
107
Eukaryotes include:
protists- mostly unicellular with 5 major groups
| plants animals fungi
108
Endosymbiosis theory
lynn Margolis
| a cyan bacteria ancestor engulfed a eukaryote
109
secondary endosymbiosis
a heterotrophic ports engulfed an alga containing chloroplasts
110
Eukaryote Features
```
biomarkers (traits)
modernn eukaryotes have:
- membrane bound nucleus
membrane bound organelles
chromosomes
cytoskeleton
```
111
closest relatives of modern plants
green algae
112
Life in water was easy because
```
bathed in nutrients
supported against gravity
extensive transport not necessary
gametes, offspring can be transmitted by water
no problem of desiccation
```
113
why leave the water?
```
direct sun light
nutrients and minerals on land
abundant CO2
absence of herbivores
new niches
```
114
sporophytes
produces spores
2n -> 1n
meiosis
115
gametophytes
produces gametes
mitosis
1n ->1n
116
Nonvascular plants
mosses, horn worts
can be abundant in moist habitats
spores and gametes similar in size
117
non vascular plants
two major break throughs
1. cuticle
2. protected embryo
118
Ferns
first vascular plant
119
angiosperms and gymnosperms produce seeds
true
120
in seed plants the sporophyte is nutritionally dependent upon the gametophyte
false; the other way around
121
the sperm of gymnosperms require water for fertilization
false; wind
122
seed plants are homosporous
false; heterosporous
123
the evolution of seeds greatly aided the colonization of drier area
true
124
fertilization occurs simultaneously with pollination
false; pollination occurs first
125
the main function of older wood, produced by secondary growth is water transport
false; structure
126
confers are the most abundant gymnosperms
true
127
fungi
more closely related to animals than to plants
chitin
store glycogen
multicellular heterotrophic eukaryotes
128
What are animals
```
metazoans
multicellular
nervous and muscle tissue
collagen
heterotrophic
embryonic development
HOX genes with specific DNA
monophyletic
```
129
animals origin
originate from protists
| multicellularity independent of plants, fungi
130
Early animals
```
porifera
no true tissues
2 cell types
choanocytes
ameobocytes
no symmetry
hermaphrodites
asexual regeneration
```
131
sponges
```
adults sessile
skeletal fibers in middle layer-> spicules
filter feeders
full of holes
create current with choanocytes flagella
```
132
Cnidarians
```
jelly fish
radial symmetry
two phases in the life cycle
-polyp
-medusa
Reproduce
sexual
asexual budding
-nematocysts
stinging organelles nerve net
```
133
Eumetazoa
```
diploblastic
two tissue layers
-ecto
end-
e.g. Cnidarians
jellyfish, coral
```
134
Bilateria
```
bilateral symmetry
cephalization
development of head
sense organs in front
direction in movement
origin: triploblasty
mesoderm- forms muscles and supports organs
```
135
Ceolemates
animals with body cavity that develops within the mesoderm
more control over movement of fluids
better support of organs and better digestions
136
protosomes
pore becomes mouth
137
deuterstomes
pore becomes ass hole
138
lophotrochozoans
mollusks, annelids, flat worms (acoelomates)
139
annelids
segmented worms
can operate segments independently
coelom
redundancy
140
segmentation
evolved multiple times in annelids
antropods
chordates
141
4 classes of mollusks
1. chitons
2. bivalves
3. gastropods
4. cephalopods
142
ecdysozoans
cuticle and molting
143
arthropods
jointed appendages
regional segmentation
exoskeleton (chitin)
open circulatory system
144
Four Phylas of Dueterostomes
1. echinodermata
2. heminchordata
3. xeno
4. chordata
145
4 chordate characteristics
1. notochord- structural support
*most distinctive derived trait
2. dorsal hollow
nerve cord
3. pharyngeal slits- feeding, then breathing
4. Muscular tail- propulsion
146
vertebrates
```
jointed skeleton
extreme cephalization
great sense orans
closed circulatory system
internal organs suspended in coelom
```
147
4 derived mammal traits
hair
lactation
three-bone middle ear
sweat glands
148
Gnathostomes
have jaws
149
tetrapods
jointed limbs
150
Hamprey & Lampreys
cartilage
no jaw
no limbs
no amniotic egg
151
chondrichthyes
```
sharks
cartilage
jaws begin
paired fins
no amniotic egg
```
152
Esteichthyes
```
ray finned fishes
bones begin
present jaw
paired fins
no amniotic egg
```
153
amphibia
```
frogs
bony
jaw present
for limbs begin
no amniotic egg
```
154
reptiles
```
lizards, turtles, snakes, birds
bony
jaw present
four limbs
AMNIOTIC EGG
```
155
Derived Traits of hominids
large brain; short jaws
forward looking eyes
complex social care
fully opposable thumb
156
hominids closest relatives
chimps and bonobos
157
1-5% of DNA can be traced back to...
neanderthals
158
Lucy
Ausralopithecus afarensis
| fully bipedal
159
Differences in courtship behavior are an example of post zygotic barriers to mating
FALSE
| prezygotic
160
A small isolated population is more likely to change into a new species than a large population
True
161
The most metabolically diverse are prokaryotes
true
162
reptiles represent a polyphyletic phylogeny
FALSE paraphyletic
163
A phylogeny is constructed using analogous characters
False; homologous
164
flat worms have a true body cavity or coelom
no coelom/ acoelomate
165
the prezygotic barrier where gametes are unable to recognize each other due to different molecular receptors is called mechanical isolation
false; gametic isolation
166
allopolyploidy is a form of sympatric speciation that involves errors in meiosis and hybridization between two different species of organisms
true
167
sponges are the first animals with true tissues
false; no tissues- Cnidarians or jelly fish are the first with true tissues
168
birds and mammals independently evolved a high metabolism
true
169
one of the 4 characteristics of all chordates is extreme chepalization
```
FALSE
notochord
tail
slits/ gills
dorsal nerve cord
```
170
when a horse and a donkey mate, they produce mules that are sterile. This is an example of post zygotic isolation
true
171
homeotic genes contribute to evolutionary novelty by altering an organism's body plan
true
172
viruses are subject to natural selection processes
true
173
after the demise of dinosaurs, the process by which mammals diversified into new species as they filled newly opened ecological niches is called adaptive radiation
true
174
a recent view of early prokaryotes states they obtained their energy from inorganic sources and their carbon from CO2. Thus, they are called photoautotrophs.
False; chemoautotrophs
175
Changes in timing or rate of developmental events such as sexual maturation are generally known as serial homologies.
heterochrony
176
protists alive today are the closest relatives to both animals and plants
true
177
The concept of species has changed over time. What is the essential aspect of the BSC.
a. individuals of a species occupy identical ecological roles
b. all members of the same genus are able to mate successfully
c. individuals within a genus share behaviors and appearance
d. individuals of a species are able to mate and produce fertile offspring in the wild
D.
178
Which of the following is the most successful (abundant) of the animal phyla?
a. annelids
b. arthropods
c. vertebrates
d. prokaryotes
b.
179
If a new animal species appears suddenly in the fossil record that is completely different from other animal species which of the following macroevolution patters would be supported?
a. gradualism
b. punctuated equilibrium
c. adaptive radiation
d. anagenesis
b.
180
peripheral and isolated populations are more likely to undergo speciation than large or connected populations, because a small population
a. contains a greater amount of genetic diversity
b. is more susceptible to gene flow
c. is more affected by genetic drift
d. is more subject to errors during meiosis
c.
181
the predominant generation in the life cycle of angiosperms is the?
a. seed
b. sporphyte
c. gametophyte
d. sperm
b.
182
what defines a chordate
a. ability to live on land
b. development of an anus from the blastopore
c. presence of a well-developed circulatory system
d. presence of four specific morphological traits
```
d.
gills/ slits
dorsal nerve cord
nochtocord
tail
```
183
One of the techniques developed by Willi Hennig for reconstructing the phylogenic histories of organisms.
a. cladograms
b. punctuated equilibrium
c. parsimony
d. anagenesis
c.
184
which of the statements below about the Fungi is correct?
a. all fungi are heterotrophs, but are able to switch to photosynthesis when stressed or the food supply is depleted
b. all fungi are asprophytic
c. all fungi receive their nutrients through absorption
d. most fungi are parasitic in their feeding methods
e. all of the above
c.
185
```
Which animals are protostomes
sponge
earthworm
roundworm
arthropod
liver fluke
sea urchin
```
earthworm
roundworm
arthropod
liver fluke
186
```
All chordates share the following characteristics
notochord
muscular tail
pharyngeal slits
3-bone middle ear
dorsal nerve cord
```
notochord
muscular tail
pharyngeal slits
dorsal nerve cord
187
```
Organisms with an amniotic egg
lamprey snakes
platypus
zebra
frogs
penguins
```
platypus
zebra
penguins
188
```
the following land plants have vascular tissue
mosses
ferns
gymnosperms
angiosperms
```
ferns
gymnosperms
angiosperms
189
one of the final steps in the formation of life is development of a system of self-replication. Explain the significance along with the problems of RNA molecules in the "RNA world." is there an alternative to RNA? explain.
1. RNA is an auto-catalyst & it self replicates
2. those forms that self-replicated through own enzyme- ribozyme were selected for in evolution
RNA can store genetic information
RNA can catalyze reactions
RNA forms that were better at at surviving and reproducing would have been a selective advantage
Problems:
without cells, products of enzyme would be shared
no one has seen large RNA self-rep
hard to imagine initial RNA molecule
maybe a pre-RNA world
proteins can form and polymerize abiotically and catalyze their own rep
190
explain the significance of oxygen to the development of life on earth- sometimes called oxygen rev
early life consisted first of organisms who were anaerobic- glycolysis with out oxygen was first form of metabolism
when photoautotrophs hit the scene O in the atmosphere increased due to increase in photosynthesis
this allowed for the evolution of aerobic organisms who used the oxygen
much more energy was produced = mor growth and activity
more energy and greater size= variety of life forms- cambrian explosion
191
what is endosymbiosis ? give some examples of this kind of relationship today. prove the evidence that supports the theory of endosymbiosis
```
explains the origin of eukaryotes as one species being engulfed by another
chloroplasts and mitochondria were once free-living aerobic prokaryotes
examples:
similar membranes
modes of replication
simple genomes
transcription
susceptible to similar antibiotics
evidence today:
solar sea slugs
protists inside animals
```
192
compare and contrast the adaptations of plants and animals to life on land.
```
plants have adapted
cuticle to conserve water
vascular tissue allows larger size
overcome gravity and able to move to land
seed
protected embryo
animals have adapted
tissues
cephalization
limbs & appendages
coelom
allowed for amniotic
egg
```
193
driving force of evolution
Symbiosis
194
define and give an example of exaptation
a trait that evolves to serve one particular function, but then it may come to serve another in a different environment.
example: bird wings- heat collectors with feathers and now used for flight
