Exam 4 Flashcards
1
Q
population
A
an interbreeding group of conspecific individuals existing in a particular place at a particular time
- spaciotemporal grouping
- most have limited geographic range which can change through time
2
Q
geneticists
A
look at individuals as collectors of genes
3
Q
gene pool
A
is the set of all different alleles at all loci in every living member of the group, pool is characterized by its gene frequencies
-phenotypic variation among all populations
4
Q
evolutionary change
A
life-forms have evolved varying characteristics as they have adapted to varied animals
5
Q
texas cougar and florida panther
A
florida panther had kink in its tail but not much other differences, so they interbreed which got rid of kink but evolutionary potential and variation was enhanced
6
Q
guppies
A
- colorful when just living alone or with killifish
- plain when living with cichlids
7
Q
protein variation
A
- no allele A in south america and a lot in canada
- allele B is not very common in americas
- O is very popular in south america
8
Q
DNA sequence variation
A
- there are sets of 3 nucleotides that specify and amino acid
- can exist and be physiologically unimportant
9
Q
3 requirements for evolution by natural selection
A
- phenotypic variation must exist among individuals
- phenotypic variation must be genetically inherited
- that variation must result in different numbers of viable offspring being produces
10
Q
violations of HWE assumptions
A
- non-random mating-
- gene flow (genetic migration)-movement of alleles from one population, homogenize allele frequencies, the rate depends on:
- rate of movement and differences in frequencies between populations - selection- not everyone is able to survive equally
- avoiding predators and matching environment - genetic drift- instead of infinitive population
- has unpredictable effects - mutation
- meiotic drive
11
Q
mummichogs
A
- LDH variation
- moving from up north to south, LDH goes down in frequency bc they do not need LDH in warm weather
12
Q
directional selection
A
- selection eliminates one extreme from a phenotypic array
- push, if a bunch of smaller animals die then the next generation will be bigger and it will shift
13
Q
natural selection
A
- you are either fit or you are not
- natural selection is the process, evolution is the outcone
- fitness differences among phenotypes lead to changes that shape population to become more fit
14
Q
stabilizing selection
A
selection acts to eliminate both extremes from an array of phenotypes
15
Q
disruptive selection
A
selection eliminates intermediate types
-beak types
16
Q
industrial melanism
A
- peppered moth
- across 1800-1850 moths near cities shifted from white morph to dark
- soot was killing tree lichens
- J Tutt and B Kettlewell developed evidence that birds selectively eat white morphs
17
Q
Skeletal Muscle
A
- striated, multinucleated, neurogenic
- extracellular Ca does not change Vm
- attached to tendons and bones so when muscles contact the bones move at joints
- moves skeleton
18
Q
cardiac muscle
A
- striated, uninucleate, myogenic
- extracellular Ca does change Vm
19
Q
Smooth muscle
A
- not striated, uninucleate, myogenic
- extracellular Ca does change Vm
20
Q
neurogenic
A
individual cells have to be told to contract by nerves
21
Q
origin and insertion
A
origin: part of bone that doesn’t move
insertion: does move
22
Q
tendons
A
attachment to bones on both sides of joint
23
Q
sliding filament model
A
-sarcomere- functioning unit
-thin filament made of actin
-myosin- thick filament
the actin is winched along the myosin by successive rounds of myosin heads pulling, each head independent
-thick filament, flat, hinge, head
24
Q
what makes the sliding filament model
A
long muscle fibers that contract by myofibrils, highly ordered arrangements of actin and myosin filaments
25
light regions
- I bands (Z line is center of I bands)
- isotropic
- thin filaments
26
dark regions
- A bands
| - thick filaments
27
sarcomere reticulum
sacs of calcium filaments
28
mechanisms of contraction
- Z lines get closer during contraction
- A band does not change in width
- I band gets narrower due to thin filament moving between thick filaments (not physically shortened)
- each I band divided in half by disc of protein
29
sarcomere
- From Z line to Z line
- smallest subunit of muscle contraction
- myofibrils contract (functionally shorten), ATP and Mg
30
Highly organized arrangement
- sets of six hexagons
- center of thick filament has more widely spread myosin molecules
- region in A band overlaps
- thick filament is able to interact with several thin filaments (series of interactions)
- thick filament change orientation during contraction to pull fibers together
31
Myosin Heads changing orientation
- Each head changes orientation independently
- pulls thin filaments closer
- makes I band narrower
- Z lines closer together
32
Contraction cycle
- myosin head has ATP, ADP, and inorganic phosphate
- head has high affinity for actin attachment
- ADP and Phosphate cause head to bind to actin
- myosin begin pulling, sharp change in orientation
- pulls thin filament toward sarcomere, releasing ATP and P
- head loses ATP and fiber dissociates
- ATP and phosphate on head shift head back to original binding sight
33
mechanisms of reproductive isolation
pre-mating: prevent wasting gametes
| post-mating: prevent hybrids from surviving and reproducing
34
pre-mating mechanisms
- geographic
- habitat preferences
- seasonal differences
- physical differences
- behavioral isolation-different cells
35
post mating mechanisms
- genetic inviability
| - hybrid inviability or sterility
36
allopatric speciation
most popular form of speciation (diversification)
- original population
- physical barrier
- reproductive contact
- differentiation/speciation (secondary contact)
37
buttercups in new zealand
the mountains made isolation and then they became different species
38
sympatric speciation
- Iris can pollinate with themselves
- apple maggot flies
- the influence of BMP4 on african cichlid jaws
39
Two views of speciation
- phyletic gradualism
| - punctuated equilibrium
40
phyletic gradualism
due to an accumulation of differences that develop due to microevolutionary mechanisms (the same ones that cause change within a population)
41
Contraction Cycle extra
- hydrolysis of ATP causes change in orientation of the head
- actual movement of actin does not require ATP
- Mg is necessary for ATP->ADP
- -myosin heads act as ATPase (ATP->ADP)
42
role of Ca in contraction
- Actin and Myosin spontaneously contract without it
- tropomyosin-blocks myosin heads access to binding to actin
- doesnt directly help, uses NT
43
troponin
- actin on tropomyosin; when a muscle is relaxed myosin cannot bind to actin bc of tropomyosin
- for contraction to occur, troponin must move tropomyosin away from actin binding sites
- its complex shape is affected by Ca binding
44
Nerve Stimulate contraction
- somatic motor neurons stimulate skeletal muscle using action potential that goes to synaptic knob and opens voltage gated channels
- Release NTs from synaptic knob that interact with endplate
- axons from a single motor neuron synapse with a # of muscle fiber cells, a motor unit
- in the motor endplate or neuromuscular junction (synapse), the motor neuron releases acetylcholine onto myofiber cell
45
when fiber is stimulated at motor endplate
- LP is produces
- edges of endplate shift shift from ion-gated to voltage gated
- then an electrical impulse (AP) travels along the fiber cell membrane down to the transverse tubules (T tubules)
- voltage gated calcium and potassium channels changes orientation and polarization
- triggering release of Ca from sarcoplasmic reticulum
- the cytoplasmic Ca concentration is raised and Ca binds to troponin
46
2 types of receptor channels
di hydropuradine- non functioning calcium ion channel
- attached to calcium ion channels in muscle of ER
- calcium channels in the tubules change shape with action potential, which unplugs
- lets calcium ion concentration in the cytoplasm of the muscle
47
excitation-contraction coupling
- dihydropuradine receptors attached to ryanodine receptors
- ryanodine receptors plug calcium channels in the ER of muscle cells
- when channel changes shape it unplugs it
- lets calcium rush out of storage sac
48
Hardy-weinberg assuptions
characteristics of the ideal population (gene frequencies and types never change)
- large
- perfect DNA population
- closed population
- random mating
- all individuals have the same ability to survive and reproduce
- meiosis is normal
49
genetic drift
agents of evolutionary change, microevolutionary change
- fluctuations are inevitable because not all (more pronounced as population size decreases)
- violation in HWE
50
founder affect
small population finding new location
51
bottleneck affect
drastic reduction in a population and gene pool size
| -lose rare alleles
52
mutations
- has made predictable effects on gene frequencies
- rates are generally low
- ultimate source of variation
53
Cause of change in color in moths
- a mutation in an intron in the cortex gene
- intron causes wings to develop too quickly
- colored scales do not develop
54
reproductive isolation
forms might be able to hybridize but won't in nature (lions and tigers)
55
morphological species
fossil species
56
trophic structure
the nutritional relationships among all the components
57
habitat
- physical surroundings
- species and community have them
- "address"
58
niche
the mode of living and resource acquisition for a give organism
- "occupation"
- multidemensional hypervolume- encompasses all the ways it uses the resources (Hudgens)
59
finches
have the same size beak when on different islands, however, when on the same island they both change so they don't compete
60
fundamental niche
entire niche potentially available to an organism
61
realized niche
actual niche utilized by an organism
| -the reduction is a consequence of interspecific-competition
62
shells of the shore in england
- chthalamus is higher up because it can close in low tide
- semibalanus needs lower portion
- chthamalus let them have it
- semibalanus can glue themselves better and knock them off if they need to
63
competition exclusion principle
over the long term, when 2 species compete for the same limiting resource, eventually 1 species will win and drive the other to extinction
-also invasive vs. native species
64
predation
- paramecium vs. didineum
- didineum drives paramecium into extinction
- didineum die after that
65
symbiotic relationship
an interaction between two or more species in which one or more species live in or on another
66
types of symbiosis
1. commensalism- bird on large herbivore +0
2. mutualism- lichens (algae and fungus) ++
3. parasitism- host is not as harmed as the parasite benefits +-
4. predation +-
5. herbivory +-
6. competition --
67
herbivory vs. predation
- prey is not usually killed
| - plant prey are often selected to develop secondary compounds that reduce their chance of being eaten
68
monarch butterfly
- cardiac glycosines obtained from milkweed
| - blue jays can't eat larvae, will throw up
69
Ecotones
- transition period when environment changes abruptly
- species change too
- increases diversity
- heterogenity in environment
70
punctuated equilibrium
- supported by geologists (fossils)
- due to rapid processes
- macroevolutionary mechanisms
- followed by long periods of stasis
71
speciation through hybridization and polypleidization
usually hybrids are sterile, but plants can self fertilize
| -meiotic error and self fertilization
72
current causes of extinctions
- habitat degradation
- pollution of air and water
- fragmentation
- over exploitation
- introduction of exotic species
73
consequences of exotic introductions
1. eating native species- brown boa killed 9/13 of native bird species in guam
2. spreading diseases- hawaiian bird flu
3. alter environment for themselves- ants
74
Main cause for extinction
It used to be habitat destruction, but now the leading cause is invasive species
75
demography
```
statistical study of populations average
Factors:
-generation time- period from egg to egg
-sex ratio- mating strategies
-age distribution
```
76
survivorship
percent of original population that survives to a give are
Type 1 curve- full life span (humans)
Type 2 curve- mortality??
Type 3 curve- early susceptibility
77
biotic potential
all populations have an intrinsic rate of increase
| -birth rate- death rate = r
78
exponential growth model
rate at which a population will increase when no limits are placed on rate of growth
- innate capacity for growth of any population is exponential
- even when rate remains constant, actual increase in # accelerates as the population size grows
- Ri=Rmax under optimal conditons
79
carrying capacity
maximum number of individuals the renewable resources can support
- K
- cant find it
80
logistic growth
- assumes that everybody contributes to the population all the time
- assumes limits of resources due to intra and interspecific competition (only intra present)
- as population approaches K, growth rate slows as resources deplete
- feedback of population size and individual contribution to growth (is anything instantaneous?)
81
population cycles
-snowshoe hares and lynx
-both oscillate with each other
-relationships are complex
-populations are linked, with a bit of a lag
(data from Hudson-Bay company; hair pellets)
82
human population is regulated by
-food availability
-disease
-pradators
with easing of constraints, growth has been exponential
83
community
- all the species that occur together in an area
- not all species in it are populations
- interactions among members
84
competition
- for resources (interspecific)
| - found in species occupying niches that overlap to some degree
85
2 types of models for population growth
- differ depending on individuals contribution to population growth
exponential: it is constant
logistic: it reduces as the population size increases
86
species interaction types
1. competition
2. predation
3. herbivory
4. perisitism
5. mutualism
6. commensalism
87
keystone species
have essential roles in facilitating other species ability to survive in an area
- beavers
- importance is greater than their abundance
- salt lick
88
Over-fishing and sea otter decline
- George's Bank fisher in western atlantic was over-fishing and closed in early 1990s, still has not recovered
- depletion of cod and other fisheries in the eastern pacific has affect area populations eating choices and has lead to sea otter decline
89
trophic cascades
- humans eat cod
- orcas eat sea otters
- rise in sea urchin
- less kelp
90
primary succession
- communities change over time
establishment: r-slected species first, tolerate harsh conditions
facilitation: early species change environment, new species start to succeed
inhibition: some new species inhibit success of previously established species`
91
climax community
self-perpetuating
| -goal community
92
community structure
equilibrium view, serial stages, and climax community
93
secondary succession
what environment experiences after a disturbance
| -change in predictable pattern
94
Island Biogeography
- developed based on observation about oceanic islands by Robert MacArthur and Edward Wilson
- rooted in equilibrium models that assume all interactions between species are similar
- proposes a species-area relationship exists
- took surveys of of islands in the pacific and plotted it
- closer to mainland= more species per island
95
Testing of island
- Simberloff studies on mangrove habitat islands suggest the interactions are more complex than the M-W model suggests
- nevertheless, the model had a significant influence on shaping thoughts in conservation bio, especially the species-area relationship
is equilibrium the best model for thinking??
96
A Role for disturbance (disequilibrium)
- an inevitable profession the seal stages of ecological succession does not seem to be the best view
- several ecosystems seem to be "arrested" in their progress due to disturbances, such as fire
- pine barrens in NJ dying out because no fire
97
disturbance of colorado river
- the damming of colorado rive for water control and agricultural use, resulted in the gradual silting of the river as it passed through grand canyon
- doesn't reach sea anymore
- periodic pulses of water
98
Island Biogeo and accidents role
1. simberloff's studies suggest that the "high" turnover of species predicted by Biogeo is not observed
2. the turnover of species that is observed seems to mainly involve rare species that never really established presence
3. who gets there first strongly influences what new forms can survive
99
Energy vs Physical components
while connected, the behavior of energy and the physical components of food in ecosystems are different
100
trophic levels
```
detrivores- bacteria and fungi
producer- plants
primary consumer- herbivore
secondary consumer- carnivore
tertiary consumer- top carnivore
-all cycle through
```
101
earth
a self-contained system with a certain amount of resources (except for energy)
102
energy
- flows through an ecosystem, with obligatory losses at each level
- plants only capture 1% of suns energy
- 5-20% of the energy is transferred at each trophic level (as an increase of biomass)
- 10% rule
ex: energy transfer in cayuga lab, algae starts off at 1000 Kcal and humans get 6 Kcal
103
role for diversity
- more diverse communities= greater stability
- field studies by Tilman and lab based animal studies by Naeem
- redundancy of species in all trophic levels impedes stability, productivity, and the rate of recovery from disturbances
104
biomagnification of toxic chemicals
- occurs up the food chains (at higher trophic levels)
| - higher trophic levels eat higher concentrations of toxins
105
DDT (pesticide)
- 1/2 life is 20 years
- banned usage in USA since 1972
- egg shells of predatory birds were thinning (peregrine falcon)
- still used outside US, used for malaria at low concentrations
106
hydrologic
- biogeochemical cycle
- oceans and atmospheres are reservoirs: evaporation, precipitation, and transpiration
- 25% (50% drinking) water comes from aquifers (ground water
problem: pollution is hard to remove, recharge rates are slow (esp for confined aquifiers)
- civilization uses over half world's accessible (surface) freshwater
107
carbon
-photosynthesis, respiration, decomposers (detritivores) are reservoirs
108
carbon cycle
- 700 billion tons in atmosphere
- .03% is CO2, which 10% is fixed by plants each year
- we put 7 billion tons of carbon into the atmosphere
109
greenhouse effect
CO2 slows escape of heat (long-wave radiation) from the earth, methane is more potent at holding in heat
110
phosphorus
- limiting resource for species (used in DNA and ATP)
- reservoirs are sentiment deposits
- phosphorus embedded in rock and banned in detergent
111
nitrogen
- atmosphere is reservoir
| - nitrogen runoff goes to more aquatic things
112
effects of agricultural water pollution
-dead zones in gulf coast and all over
113
dead zone in gulf coast
- attributable to nitrogen and phosphorus releases into Mississippi river upstream (fertilizer)
- 1999 study found nitrogen was major component at marine side of efflux, resulting in plan to reduce release from upstream sites by 30% by 2015 (not successful)
114
effects of El Nino on Degus
- el niño increases rainfall and creates pulses of increased food availability
- prolonged droughts: lower survival, produced fewer progeny, with lower persistence
- high rainfall in subsequent year: reverses same characteristics, plus trend continues into consecutive wet years
