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Evolution > Exam 1 Lecs - 4 > Flashcards

Exam 1 Lecs - 4 Flashcards

1
Q

evidence of founder:
- Polynesian field crickets: native to … and …
found on …, including …

A

Australia;
New Guinea;
Pacific Islands;
Hawaii

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2
Q

evidence of founder:
Polynesian Field Crickets:
- Crickets dispersed across the Pacific Islands:
expectation is that there’s …/… on the islands, we expect to find … and we expect to see …/…

A

drift; founder events;
small number of alleles;
fixed/lost alleles

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3
Q

evidence of founder:
Polynesian Field Crickets:
Crickets dispersed across the Pacific Islands:
- Each island’s population would likely have been founded by a …
- sampled 394 crickets from 19 pops at seven … (…, can’t be under …, …)

A 
small number of individuals; 
microsatellite loci; 
noncoding DNA; 
selection; 
neutral
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4
Q

evidence of founder:
Polynesian Field Crickets:
Crickets dispersed across the Pacific Islands:
- sampled 394 crickets from 19 pops at seven microsatellite loci (noncoding DNA, can’t be under selection, neutral):
microsatellites have many ….

Sampled mainland Australia and the pacific islands –> For the mainland samples, frequency of alleles was … But in Pacific Islands, we see … of …

A

easily identifiable alleles;
distributed more among numerous alleles;
higher frequency; fewer alleles

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5
Q

evidence of founder:
Polynesian Field Crickets:
Sampled mainland Australia and the Pacific Islands:
- For the mainland samples, frequency of alleles was distributed more among numerous alleles. But in Pacific Islands, we see higher frequency of fewer alleles –> islands have … and … alleles with … –> some alleles from mainland … in island populations
This is evidence of founder events and the impact of drift over several gens

A

less genetic diversity;
fewer;
higher frequencies;
aren’t present

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6
Q

Evidence of founder:
Pingelapese people of Eastern Caroline Islands:
- population made up of survivors of …
- … occurred also
- among survivors were carriers of a … allele in … cells

A

typhoon;
famine;
recessive loss of function;
cone

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7
Q

Evidence of founder:
Pingelapese people of Eastern Caroline Islands:
- among survivors were carriers of a recessive loss of function allele in cone cells (i.e. cells that enable us to see …) –> people with that gene have … cone cells and …

A

color;
non-functioning;
extreme sensitivity to light

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8
Q

Evidence of founder:
Pingelapese people of Eastern Caroline Islands:
Among survivors were carriers of a recessive loss of function allele in cone cells (i.e. cells that enable us to see color)
- completely … with … as well
- condition is called …

A

color blind;
poor vision;
achromatopsia

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9
Q

Evidence of founder:
Pingelapese people of Eastern Caroline Islands:
- Condition called achromatopsia: …, frequency is … people worldwide. However, in the Pingelapese the frequency is …

A

rare;
1/20,000;
1/20

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10
Q

Evidence of founder:
Pingelapese people of Eastern Caroline Islands:
- … by the typhoon, a founder event, left the allele at a frequency of at least …. It’s now more than …

A

sampling error;
2.5%;
20%

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11
Q

Evidence of founder:
Pingelapese people of Eastern Caroline Islands:
Sampling error by the typhoon, a founder event, left the allele at a frequency of at least 2.5%. It’s now more than 20%:
- this change in frequency: no … to island so no new alleles coming in, the key point though is = …(it’s …)

A

migration;
random drift;
increasing by chance

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12
Q

Evidence of founder:
Pingelapese people of Eastern Caroline Islands:
- this change in frequency due to random drift: when the population is very small, … is not strong enough to reduce frequency of the allele. … is stronger in smaller populations

A

selection;

drift

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13
Q

Evidence of founder:
controlled lab experiment on fruit flies:

Buri studied … and … empirically

A

random fixation;

loss of heterozygosity

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14
Q

Evidence of founder:
controlled lab experiment on fruit flies:

Buri studied random fixation and loss of heterozygosity empirically:

  • established 107 pops of flies, .,.. and … as starting population
  • All of the founders were … for brown eyes (allele …)
A

8 males;
8 females;
heterozygous;
bw75

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15
Q

Evidence of founder:
controlled lab experiment on fruit flies:
Buri established 107 populations of flies, 8 males and 8 females as starting population:
- he maintained these pops for … generations and kept the population size at … by picking 8 females and 8 males …

A

19;
16;
at random

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16
Q

Evidence of founder:
controlled lab experiment on fruit flies:

Buri maintained these pops for 19 generations and kept the population size at 16 by picking 8 females and 8 males at random –> what results would we predict for allele bw75? A: It can … or … since it’s …

Over the generations, most populations had either … the frequency of the allele or … the frequency of the allele

A

either increase; decrease; random;
fixed;
lost

17
Q

Evidence of founder:
a controlled lab experiment on fruit flies:
Why is the number of populations with frequency 0 is approximately the same as frequency 1?
- partly bc its …
- primarily bc … of the allele was …

A

random;

initial frequency; 0.5

18
Q

Evidence of founder:
controlled lab experiment on fruit flies:
Why is the number of populations with frequency 0 is approximately the same as frequency 1?
- primarily bc initial frequency of the allele was 0.5. From the beginning, half of the alleles were bw and half were bw75. Equal chances of either … or …
If initial frequency was about 0.9 for bw75, you’d expect to have more populations …

A

fixing;
being lost;
fixing the allele

19
Q

Evidence of founder:
controlled lab experiment on fruit flies:
What happens to heterozygosity as bw75 is drifting toward fixation or loss in the population?
- …
- heterozygosity plot is similar to a … with …

A

decreases;
straight line;
negative slope

20
Q

Evidence of founder:
controlled lab experiment on fruit flies:
… acted as one of the main forces of evolution in Buri’s flies and it was …

A

drift;

totally random

21
Q

Evidence of founder:
Natural experiment looking at the same things:
Alan Templeton tested predictions about … in Missouri’s Ozark mountains
This region is now mostly forest and savannah nviro
between 8000 and 4000 ya, … invaded the desert region. But then, climate changed again and … began invading the region again

A

random fixation of alleles;
forest;
savannah

22
Q

Evidence of founder:
Natural experiment looking at the same things:
Exposed rocky outcrops called the … In those isolated pockets of desert, can find populations of …
In the 50s, they … in this environment

A

glades;
collared lizards;
suppressed fire

23
Q

Evidence of founder:
Natural experiment looking at the same things:
In the 50s, they suppressed fire in this environment:
- lizards could migrate between those outcrops when … occur. Suppressing fires … the lizards more - …

A

fires;
isolated;
stopped migration

24
Q

Evidence of founder:
Natural experiment looking at the same things:
In the 50s, they suppressed fire in this environment:
- they then sampled the lizards and sequenced the DNA at MDH, mtDNA (mitochondrial) and rDNA(ribosomal), looking at … in those regions
- found that in several outcrops, the individuals were … genetically –> this is bc pop is …, there’s …, and alleles are being … and there’s no …

A 
variants; 
all the same; 
small; 
drift; 
fixed; 
migration
25
Q

Evidence of founder:
Natural experiment looking at the same things:
In the 50s, they suppressed fire in this enviro:
- found that in several outcrops, the individuals were all the same genetically. … in populations is also due to drift, too
- proposed that the nearly complete loss of … in those populations doomed the lizards to …

A

differences;
genetic diversity;
extinction

26
Q

Evidence of founder:
Natural experiment looking at the same things:
- Proposed that the nearly complete loss of genetic diversity in those populations doomed the lizards to extinction: suggested that local extinctions would occur through two forces: …, changes in … and …

A

pathogens;

biological; physical environment

27
Q

Evidence of founder:
Natural experiment looking at the same things:
- proposed that the nearly complete loss of genetic diversity in those populations doomed the lizards to extinction. Suggested that local extinctions would occur through two forces: pathogens, changes in biological and physical environment
- pathogens are an issue bc there can’t be any … without … –> if pathogen can kill one lizard from that population, since they’re all the same, it’ll ….
- Same reasoning for changes in enviro

A

selection;
genetic variation;
kill all of them

28
Q

Evidence of founder:
Natural experiment looking at the same things:
- They surveyed more glades. Consistent with their expectations, … of the glades had …

A

2/3rds;

no lizards

29
Q

Young and colleagues reviewed evidence of these processes among populations of various sizes:
- compiled data on three … and a … Plotted measures of … against …

A

flowering herbs;
tree;
diversity;
population size

30
Q

Young and colleagues reviewed evidence of these processes among populations of various sizes:
Compiled data on three flowering herbs and a tree. Plotted measures of diversity against pop size
- there is a correlation where, as size increases, diversity … (vice versa too):
small sizes: drift …. as some alleles are fixed and others lost
size of population can be measured from …/… –> the …

A

increases as well;
removes variation;
genetic diversity; polymorphism;
effective population size

31
Q

Effective pop size: size of an ideal … that would … at the same rate as an …

A

theoretical population;
lose heterozygosity;
actual population of interest

32
Q

effective pop size:
measure of variation is proportional to … –> can measure population size with …
This is a … number though so the effective pop size is pretty much always … than the actual size

A

size of population;
genes;
theoretical;
smaller

33
Q

effective pop size:
-For humans, all the genetic diversity we have among 7 billion people is actually equivalent to an idealized population size of … –> we’re …

A

100,000;

very similar

34
Q

random drift:
bc fluctuations in allele
- frequency are random, every population follows a … evolutionary path
- Genetic drift is more … and … in small populations than large

A

unique;
rapid;
dramatic

35
Q

random drift:
- Genetic drift is more rapid and dramatic in small populations than large: in small populations, have …
Bigger sample has … –> if you take a larger sample of a population, that sample is a … of that population

A

higher sampling error;
smaller error;
better representation

36
Q

random drift:
- given sufficient time, drift can produce substantial changes in … even in populations that are … –> drift is … in larger populations but it still changes … with enough time (will be … needed for larger populations)

A 
allele frequencies; 
fairly large; 
weaker; 
allele frequencies; 
more time

Evolution (27 decks)

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