Brainscape's Knowledge GenomeTM

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


See full index

Ecology and Evolution Unit 1 & 2 > Unit 1: Mechanisms Evolution > Flashcards

Unit 1: Mechanisms Evolution Flashcards

https://quizlet.com/661802042/intro-to-evolution-flash-cards/

1
Q

What processes cause evolution?

A
  1. Natural selection
  2. Genetic drift
  3. Migration
  4. Mutation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Natural Selection?

A
  1. reproduction of individuals with favorable genetic traits that survive environmental change because of those traits, leading to evolutionary change
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Variation?

A

genetic differences among individuals in a population

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

Who are Peter and Rosemary Grant?

A

Study Darwin’s finches on the Galapagos Islands and have measured evolution by natural selection over short time scales

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

What are the 4 Postulated of Natural Selection?

A
  1. Variation exists among individual organisms in a population
  2. Some of that variation is heritable
  3. Survival and reproduction success is variable
  4. Individuals best able to survive and reproduce is not a random sample
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain Postulate 3 of Natural Selection.

A
  • Populations produce more offspring than can survive
  • Resource limit populations, lead to struggle for existence
  • Some individuals reproduce more than others
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a Polygenic Trait?

A

controlled by multiple genes
(ex: expressions of Bmp4 which effects width and depth)

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

What is Adaptation?

A

heritable traits or behavior in an organism that aids in its survival and reproduction in its present environment
Note: that environments change, and thus the trait that is adaptive can also change

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

What is Heredity?

A

the transmission of genetic characteristics from parents to offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is heritability?

A

the fraction of population variation that can be attributed to its genetic variance

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

What did Gregor Mendel discovery?

A

(1822-1884)
- Each parent passes a combination of discrete ‘factor’ (alleles or genes)
- Each gamete carries only one factor
-Factors segregate independently during gamete formation
- Dominant and recessive factors

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

Was Gregor Mendel’s work known by Wallace and Darwin?

A

Yes

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

What is Evolutionary Fitness?

A

individual’s ability to survive and reproduce

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

What is Relative Fitness?

A

individual’s ability to survive and reproduce relative to the rest of the population

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

What is Selection Pressure:

A

environmental factor that causes one phenotype to be better than another (abiotic or biotic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Who studies Genetic basis of adaption and Morphology & behavior in mice?

A

Hopi Hoekstra

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

Name the types of Selections.

A
  1. Stabilizing selection
  2. Directional selection
  3. Diversifying selection
  4. Frequency-dependent selection
  5. Negative free-dependent selection
  6. Sexual selection
  7. Artificial selection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In Stabilizing selection, Phenotype higher AND lower than the mean has __________.

A

low fitness

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

In Stabilizing selection, mean __________________.

A

stays the same

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

In Stabilizing selection, Genetic variation is _______.

A

reduced

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

In Directional selection, Phenotype higher OR lower than the mean has _______.

A

highest fitness

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

In Directional selection, the mean move in the direction with the ______ fitness.

A

higher

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

In Directional selection, Genetic variation is _______.

A

reduced

24
Q

In Diversifying selection, Phenotype higher AND lower than the mean has the ____ fitness

A

high

25
Q

In Diversifying selection, the mean ___________________.

A

COULD stay the same

26
Q

In Diversifying selection, Genetic variation is ________.

A

increased

27
Q

Positive frequency-dependent selection is understood to be

A

stabilizing selection

28
Q

What is Negative frequency-dependent selection?

A

is a type of diversifying selection when considered over multiple generations

29
Q

In Negative frequency-dependent selection the ____ type has a higher fitness.

A

rare

30
Q

In populations with sexual dimorphism, the ____ are typically more decorated, larger , or stronger.

A

males

31
Q

What is Sexual Selection?

A

selection that favors phenotypes that increase ability to obtain or choose good mate

32
Q

Who does Sexual Selection often act on? And Why?

A

Males, because of fundamental asymmetry of sex

33
Q

What is Fundamental Asymmetry of Sex?

A

females invest more in their offspring than do males

34
Q

What does Sexual Selection predict?

A

females should be choosy, males compete with each other

35
Q

What is Artificial Selection?

A

Deliberate manipulation of fitness by humans through selective breeding

36
Q

What type of Selection molds domesticated plants and animals?

A

Artificial Selection?

37
Q

What leads to genetic drift?

A

sampling error in sexual reproduce

38
Q

Individuals are ______ & produce gametes that are ______.

A

diploid (2n), haploid (n)

39
Q

Gametes contain _________ of an individual’s alleles

A

random sampling (50/50 probability for each allele)

40
Q

Allele frequencies therefore ______ across generations.

A

“drift”

41
Q

The magnitude of the drift is INVERSELY related to the population size:

A

large population size = low genetic drift
small population size = high genetic drift

42
Q

Genetic Drift can lead to _____ or ____ of alleles, which reduces genetic diversity.

A

loss (freq = 0), fixation (freq = 1)

43
Q

What causes Genetic Drift?

A
  1. Bottleneck effect (sudden reduction in population size)
  2. Founder Effect (dispersal over a barrier)
44
Q

Genetic drift affects the whole genome and is random with respect to fitness.

A

True

45
Q

Genetic drift will usually result in a _______ in average fitness.

A

reduction

46
Q

What does Migration (gene flow) do to populations on a genetic scale?

A

makes populations more similar genetically

47
Q

Migration can _____, ____, or have ____ on fitness & genetic diversity

A

increase, decrease, no effect

48
Q

What are Mutations?

A

changes to DNA & ultimate source of new alleles

49
Q

Mutations ____ genetic diversity.

A

increase

50
Q

Mutation are generally random.

A

True

51
Q

List Mutations effects on Phenotypes.

A
  1. None (neutral)
  2. Changes in protein or protein expression
  3. Absence of protein
52
Q

Since most organisms are well adapted to their environment, mutation in coding/regulatory regions most often _____ fitness (deleterious)

A

lower

53
Q

Which mutations are heritable?

A

only germ lines

54
Q

(Evolutionary Impacts) low rates = ____

A

slow changes

55
Q

New mutations have very little effect on allele frequencies.

A

True, the frequency of novel allele is 1/2n

56
Q

What does the fate of new alleles depend on?

A
  1. Natural Selection
  2. Genetic Drift
  3. Migration

Ecology and Evolution Unit 1 & 2 (12 decks)

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