Making of the Fittest Flashcards
(153 cards)
1
Q
Ice Fish of Bouvet Island
A
Crocodile Icefish have no hemoglobin or red blood cells
2
Q
Bouvet Island is the (blank)
A
most remote island in the world
3
Q
Who discovered Bouvet island?
A
Rupert Gould in 1739
4
Q
Who first landed on Bouvet island? When?
A
1927 Norweigen expedition
5
Q
Who first discovered “white crocodile fish”
A
Rustad
6
Q
Who was interested in pale/translucent fish with colorless blood after Rustad discovery?
A
johan Ruud- 1953
7
Q
Hemoglobin
A
carries oxygen
8
Q
Why did icefish evolve?
A
Change in environment
- 33-34 mya Antarctica broke away from SA and changes in ocean currents isolated waters around Antarctica
- limited migration of fish; adapt or extinct
- Notothenioid 200 species dominant
9
Q
When a change in the environment occurs, organisms either (blank) or (blank)
A
adapt or die
10
Q
Why did icefish evolve?- big picture
A
Change in environment, isolated population
11
Q
Psysiology changes due to
A
drop in water temp
12
Q
Colder water leads to (blank)
A
drop in metabolic rate, less oxygen required
13
Q
3 critical points to describing how the fish have no red blood
A
- colder water leads to drop in metabolic rate, and less oxygen is required
- oxygen solubility increases
- viscosity increases, making it difficult to pump blood
14
Q
Hematocrit
A
% of RBC in blood
15
Q
Humans have (blank) % hematocrit
A
45
16
Q
most antarctic fish have (blank) % hematocrit while icefish have (blank)
A
15, 1
17
Q
Elements of blood
A
- red blood cells
- platelets
- blood plasma
- white blood cells
18
Q
no red blood cells means no
A
hemoglobin
19
Q
what is the consequence of no hemoglobin?
A
O2 carrying capcity of blood is 2-3% of normal blood- adding hemoglobin increases carrying capacity 70-fold
20
Q
what adaptations made it possible to get the oxygen the icefish needed
A
large gills, scaleless skin, unusually large capillaries, large heart, more blood volume
21
Q
what do icefish also not express in muscles?
A
myoglobin
22
Q
hearts of (blank) species also don’t have myoglobin and therefore they have
A
5, pale larger hearts
23
Q
What do the the pale hearts do?
A
- mutation in myoglobin gene
- myglobin expressed in muscles, related to hemoglobin
- has heme molecule that binds oxygen, takes oxygen from blood to muscles
24
Q
Adaptation not limited to modification or loss of genes, but also (blank)
A
invention of genes
25
Plasma of antarctic contains (blank)
chock-ful of antifreeze proteins
26
antifreeze proteins help what
fish survive in icy waters by lowering temperature threshold at which ice crystals can grow
27
antifreeze gene arose from (blank)
unrelated gene for a digestive enzyme
28
explain how antifreeze gene arose from unrelated gene
- chromosomal mutation (duplication)
| - new gene with new function created
29
Function of antifreeze gene
prevents ice crystals from forming
30
new proteins/functions are often (blank)
derived from something that already exists
31
stages of icefish evolution
- all 200 species have antifreeze
- 15 species lost hemoglobin genes
- 5 species lost myoglobin
32
Scientists tried to use anti-freeze gene to protect plants from frost to no avail. What can you conclude about the effect of icefish antifreeze genes on cold tolerance tomatoes? Under these conditions, does the antifreeze gene have a positive, negative, or neutral impact on survival?
no change/ neutral
33
What are immortal genes?
genes necessary for spark of life (run central dogma) and running in place for eons
34
Immortal genes
- 500 genes homologous across all living organisms
- demonstrates power of natural selection to preserve DNA record
- demonstrates the descent of life from common ancestor
- genes don't avoid mutation
- mutation = lethal
- life is not possible with a mutation in one of these genes
35
Immortal genes demonstrate
- power of natural selection to preserve the DNA record
| - descent of life from a common ancestor
36
Immortal genes show
- how natural selection rejects changes that are harmful
| - deep homology
37
immortal genes encode
proteins that are involved in carrying out the central dogma processes
38
What is an example of an immortal gene?
EF1-a (elongation factor 1 a)
39
Mutations are (blank) in immortal genes
purged
40
How do new capabilities arise?
- new functions/genes are made from old genes
| - icefish antifreeze protein
41
Explain creation of icefish antifreeze protein
duplication and divergence, trypsinogen gene was duplicated, the one copy diverged and changes accumulated that led to a new protein with a new function
42
Vertebrate eye and color vision shows a great example of
evolution
43
Animals with different environments have
adaptations in color vision that are optimal for their environments
44
Rod and cone found in (blank)
retina that detects light and transmits it to brain
45
Rod detects
dim light
46
Cone detects
color light
47
Rods and cones are
cells of retina that detect light
48
Rods and Cones are filled with (blank)
opsin proteins
49
Opsin changes shape when it (blank)
absorbs light, signal sent to brain
50
Humans 3 opsins
SWS0 absorb short wavelength
MWS absorb medium wavelenght
LWS absorb long wavelenght
51
Color blindness is caused by
genetic loss of one opsin
52
Protanopia
missing red cone (LWS)
53
Deuteranopia
missing green cone (MWS)
54
Tritanopia
missing blue cone (SWS)
55
Most mammals have (blank) opsins
2
56
hunting example
deer only have 2 opsins and can't see orange (no MWS)
57
Third opsin evolved by (blank)
duplication and divergence
58
All old world apes and monkeys have (blank) opsins
3
59
New world and other mammals have (blank) opsins meaning they are
2, dichromatic
60
What happened to create the mammalian MWS/LWS opsin gene?
chance duplication event that allowed for ability to differentiate between red and green
61
Gene duplication in old world primates added (blank)
LWS opsin
62
What is an advantage of having trichromatic vision?
gathering food; differentiating between ripe and nonripe
63
Other vertebrates have better or worse color vision than mammals? why?
better- 4 opsin genes
64
Color vision occurred early or late in vertebrate evolution?
early
65
Why did early mammals lose opsin genes and then regain them later on?
Early mammals were small, nocturnal so they could stay hidden in an ecosystem dominated by dinosaurs
66
natural selection acts on opsins in animals living in different environments because-
to allow for better survival
67
In dim light found in deep oceans, (blank) and (blank) are responsible for vision
rods and rhodopsin
68
deep-sea fish and dolphins have rhodopsin that is (blank) to better absorb blue light
shifted
69
What occurred that had an immense importance on animals ability to see dim light in ocean?
shift 15 to 20 nm to be able to pick up blue light better
70
Natural selection works on genes that are
in use and allows others to decay
71
Many birds have a (blank) that allows them to detect (blank)
tuned SWS opsin; UV light
72
How did scientists discover that birds are able to see UV light?
birds see the markings on the heads for mating through opsins that detect UV light and was discovered through sunscreen experiment
73
Natural selection is (blank) to changes that are neutral
blind
74
What is an example of a shift in a species lifestyle that involved the formation and fine tuning of genes
icefish and antifreeze
75
how is natural selection blind to changes that are neutral?
- formation and tuning of new genes (antifreeze)
- abandoning of genes (hemoglobin and myoglobin)
- text of genes breaks apart and erodes over time (mutations)
- use it or lose it
76
relaxation of natural selection is
specific to individual genes and particular species
77
What does fossilization mean?
remenant of past; no longer function
78
How can "fossilization" of a gene occur?
- nonsense mutation: no protein produced
- mutation in regulatory sequence responsible for turning transcription on- no protein produced
- mutation occurs in gene for protein required for DNA replication
79
Mutations aren't more common in (blank) genes or less common in (blank) genes
unused
| important
80
icefish are the perfect illustration of
fossil genes
81
fossil genes in icefish
hemoglobin- O2 transport in blood
| myoglobin- O2 storage in muscle
82
Fossil SWS opsin gene in coelacanths
dim blue light- functioning rhodopsin
lack gene for LWS/MWS mutations
color vision provides no advantage
83
Fossil SWS opsin gene in blind mole rats
- small eyes, covered by skin but use light sensation to orient biological clock
- SWS fossilized
- functioning rhodopsin
- functioning LWS/MWS- detect red
84
If environmental changes occur, bodies say are we going to use gene or no? if yes...
natural selection continues to prune
85
number of fossil olfactory genes in mice
1400
86
Fossil olfactory genes in humans
- smell is perceived by olfactory receptors on neurons
- 50% fossilized
- trichromatic vision evolved, less need
87
A change in the environment will change
the selection pressures
88
relaxed selection on gene leads to
decay
89
What is required for fossilization of a gene?
- change in environment (relaxed ns)
| - mutation
90
convergent evolution
- concept of 2 different species acquiring different traits independently of each other
- natural selection repeats independently
91
Example of convergent evolution with antifreeze protein
also in Northern Cod in arctic waters from different enzyme at different timeframe
92
trichormatic color vision has evolved in
new world howler monkeys
93
old world monkeys have trichromatic or dichromatic?
tri
94
new world monkeys have tri or di?
di except for howler monkeys
95
four pieces of data for convergent evolution with howler monkey example
1) howler monkeys are more related to new world than old
2) common ancestor doesn't have trichromatic vision
3) size of duplication event is larger in howlers
4) duplicate sequences indicate that it is more recent
96
according to the tree of primates based on DNA sequences, two pieces of data for independent duplication and convergence is....
- size of duplicated section containing opsin (larger in howlers than OW primates)
- in OW monkeys, duplicated opsins differ by 5% rather than howlers is 2.7%- more recent
97
Coelacanths and cetaceans both have
SWS fossil gene nonfunctional
98
How did the coelanth SWS gene fossilize
stop codon
99
How did the cetacean (dolphin) SWS gene fossilize
deletion, frameshift
100
Why did the SWS opsin gene fossilize in both coelacanths and cetaceans?
no longer needed in dim waters
101
What is another example of convergent evolution besides deep water and howler monkeys?
marsupials and placental animals
- common ancestor 120 mya
- species evolved independently but filled similar niches
102
How does nature make the fittest? (1st point)
given sufficient TIME
103
How does nature make the fittest? (2nd point)
identical or equivalent mutations will arise repeatedly by CHANCE
104
How does nature make the fittest? (3rd point)
their fate (preservation or elimination) will be determined by the conditions of SELECTION upon the traits they affect
105
What is evo-devo?
-major evolutionary change can result from subtle changes in distribution of signaling molecules and sensitivity of noncoding regions of DNA that control gene expression
106
What three things impact evo-devo change?
space, time, quantitative (amount)
107
Evolutionary developmental biology
study of the relationship between development and evolution
108
How can small genetic changes result in large changes in phenotype?
principles of evo-devo
109
What are the 5 principles of evo-devo? #1
1) Organisms share similar mechanisms for development that include a "toolkit" of signaling molecules that control gene expession
110
What are the 5 principles of evo-devo? #2
Signaling molecules can act independently in different tissues and regions, enabling modular evolutionary change.
111
What are the 5 principles of evo-devo? #3
Developmental differences can arise from changes in the timing of signaling molecule action, location of the action, or quantity.
112
What are the 5 principles of evo-devo? #4
Differences among species can arise from alterations in expression of developmental genes.
113
Example of differences among species arising from alterations in gene expression
finch beak look changes with protein level change
114
What are the 5 principles of evo-devo? #6
Developmental changes can arise from environmental influences.
115
When developmental biologists began to describe differentiation and development at the molecular level, what did they find?
common regulatory genes and pathways in many organisms
116
What is an example of common regulatory genes and pathways among organisms?
eye development in fruit fly and mice
117
Gene sequences for eye development are highly (blank( in many species
conserved
118
Homologous genes
evolved from a gene in a common ancestor
119
What genes determine pattern formation?
Hox genes
120
The Hox gene cluster is an example of
homology
121
Hox genes code for (blank)
transcription factors that provide positional information and control pattern formation in body segments
122
Homologous sequence in hox genes
homeobox
123
How may Hox genes have arisen?
gene duplication- mutated copies take on new copies and other retain original
124
(blank) and (blank) in Hox genes is suggested by the increase in the number of Hox genes in different animal groups
Duplication and divergence
125
Hox genes show (blank) patterns
similar expression
126
Hox genes have been (blank) over many years
conserved
127
What principle of evo-devo do Hox genes describe?
#1
128
How can mutations with large effects change only one part of the body?
modules
| -genes controlled separately in modules so structures can change independently
129
Modules
functional entities consisting of genes, signaling pathways, and the physical structures that result
130
genetic switches control
how the genetic toolkit is used (signaling pathways involving promoters and TFS)
131
elements of the genetic toolkit can be involved in (blank) processes while still allowing individual modules to develop (blank)
multiple developmental
| independently
132
single or combination of Hox genes determine
pattern and formation
133
in embryos, genetic switches do what in relation to pattern and function?
integrate positional information and determine developmental pathways for each module
134
Hox genes drive
certain developmental processes
135
Segments (blank) under control of genetic switches in flies- ex?
differentiation
| mutation of Ubx protein = develop of 2 wings
136
Modularity allows for (blank) in expression of structural genes
differences
137
Heterometry
differences in the amount of gene expression
138
Beak size and shape in Galapagos finches is regulated by the
relative amounts of proteins produced by two regulatory genes
139
heterometry in finches example
mutations in 2 genes or development pathways dictate beak size which enables new food sources
140
cactus finch
low BMP4- low beak depth/width
| high CaM- elongated beak
141
ground finch
Moderate BMP4- moderate beak depth/width
Early/high BMP4- high beak depth/width
Low CaM: short beak
142
Heterochrony
changes in timing of gene expression
143
What is an example of Heterochrony?
neck bones of giraffe
144
Heterochrony giraffe example explanation
bone growth results form proliferation of cells called chondrocytes- growth stops when cells receive apoptosis signals
145
Why are the necks longer in giraffes?
signaling delayed
146
Heterotopy
spatial differences in gene expression
147
heterotopy example
all bird embryos have webbing between their toes
| retained in ducks not chickens
148
Loss of webbing is controled by (blank)
BMP4- protein that instructs cells in webbing to undergo apoptosis
149
In ducks a gene called (blank) encodes.... which leads to webbing
Gremlin encodes BMP4 inhibitor which is expressed in webbing cells
150
(blank) expression maintains webbed feet in ducks
gremlin
151
In ducks
Gremlin inhibits BMP4- no apoptosis and webbing
152
In chickens
No Gremlin- no inhibiting of BMp4- no webbing
153
What are the 3 concepts that dictate differential gene expression?
amount (heterometry)
timing (heterochrony)
spatial (heterotopy)
