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Bio Evolution > final exam- sexual selection and seciation and pop gen > Flashcards

final exam- sexual selection and seciation and pop gen Flashcards

(109 cards)

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1
Q

what does non-random mating consist of?

A

intering breeding and sexual selection

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2
Q

Inbreeding increases?

A

Increases homozygosity

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3
Q

Inbreeding Depression

A

Due to increase homozygosity causes A decline in average fitness

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4
Q

How does increasing homozygosity decrease fitness?

A

Many recessive alleles -> loss of function
Inbreeding -> increases deleterious, lethal alleles
Disease fighting alleles
—Often under natural selection for heterozygous advantage

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5
Q

sexual selection

A

a type of natural selection that favors individuals who have a combination of heritable traits that are most useful in obtaining a mate

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6
Q

Sexual Dimorphism

A

when the males are physically distinct from females

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7
Q

what are useful traits for males to attract females?

A

physical beauty, physical skills, parenting skills and Physical strength, weaponry

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8
Q

Bateman-Trivers Theory

A

Eggs are expensive and sperm is cheap

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9
Q

how are eggs “expensive”?

A

Females produce relatively few offspring in a lifetime and
A female’s fitness is primarily limited by ability to
gain resources to make more eggs, healthy young
(not ability to find a mate)

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10
Q

How are sperm simple to produce?

A

Males can father virtually unlimited numbers of offspring

Fitness limited by number of females they can mate with; not the ability to require resources to make sperm

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11
Q

Asymmetry of Sex

A

Females invest a lot in each offspring, males don’t

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12
Q

Female Choice

A

Females need to be choosy about their mates

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13
Q

males should be..

A

Males should be willing to mate with any female possible

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14
Q

Male-to-male competition uses?

A

useful trait (physical strength)

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15
Q

Colorful feathers, colorful beaks ~ due to

A

carotenoids

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16
Q

what does Carotenoids do?

A

protect tissues, stimulate immune system

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17
Q

Where do animals get carotenoids?

A

plants

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18
Q

Traits that evolve due to sexual selection should be found primarily in

A

males

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19
Q

speicies

A

An identifiable group;
distinct in appearance, behavior and habitat,
that regularly interbreeds,
and is evolutionarily independent from others

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20
Q

How do species come about?

A

Genetic isolation to Genetic diversion

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21
Q

What is speciation?

A

The creation of two or more distinct species from a single ancestral group

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22
Q

how are new species decided upon?

A

speicies concepts

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23
Q

Biological Species Concept

A

Distinct species defined by reproductive isolation

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24
Q

different species- biological concept

A

When two populations do not interbreed

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25
same species by biological concept
groups that naturally or potentially interbreed but are reproductively isolated
26
Disadvantages of biological concept?
Not useful with fossils Not useful with asexual organisms Not useful with related species that are geographically isolated
27
Morphospecies Concept
Based upon idea that distinguishing features arise when populations are isolated from gene flow
28
morphology
body form, shape
29
Advantage of Morphospecies Concept
- applies to sexual and asexual organisms | - applies to extinct species
30
Disadvantage of Morphospecies Concept
“features” are subjective
31
Phylogenetic Species Concept
Based upon common ancestory | Tree of life – tip of each branch = phylogenetic species
32
advantages of Phylogenetic Species Concept
sexual, asexual organisms | extinct species
33
disadvantages of Phylogenetic Species Concept
limited phylogenies available | recognizes many more species than other two concepts
34
Tip of each branch
phylogenetic species
35
Clusters at tips
populations within a species (subspecies)
36
Monophyletic group
“clade” = lineage
37
Allopatry
“different homeland” | populations become physically separated
38
Dispersal
move to new habitat
39
Vicariance
physical splitting of habitat
40
Sympatry
“together homeland” | populations in same geographic area or close enough to allow interbreeding
41
Vicariance events result from
Continental shift Development of mountain ranges Changes in the course of rivers Movement of glaciers
42
population fusion
Two populations interbreed, lose distinguishing features | Become one large population
43
Reinforcement
Differences between species persist; remain divergent
44
Mechanisms of Genetic Change
``` Natural Selection Genetic Drift Gene Flow Mutation Non-Random Mating / Sexual Selection ```
45
Prezygotic mechanisms (5) that prevent mating
``` Temporal Habitat Behavioral Gametic (= relating to gametes) Mechanical ```
46
Postzygotic mechanisms that prevent new species
Hybrid viability | Hybrid sterility
47
what is population genetics?
The study of changing heritable characteristics of populations over time or the study of changing allele frequencies in populations under the effects of various evolutionary processes
48
Natural Selection
The process by which individuals with certain heritable traits have a survival advantage and thus a reproductive advantage
49
Genetic drift
random change in allele frequency (may increase or decrease fitness); founder effect, bottleneck event
50
Gene flow
when individuals move back and forth between 2 populations
51
Sexual Selection
a form of non-random mating
52
Mutation
permanent change in base sequence of DNA; continuous introduction of new alleles (may increase or decrease fitness)
53
Mechanisms that alter heritable characteristics in populations
natural selection, genetic drift, gene flow, sexual selection and mutation
54
Godfrey Hardy, Wilhelm Weinberg (1908)
Fathers of the science of population genetics and | Considered genetics within entire populations, not just one set of parents and their offspring (Mendel, Punnett, Morgan)
55
hypothesis
educated idea that can be tested
56
Ho
null hypothesis (Ho) is the one that states that there is no significant difference between treatment group and control group
57
Ha
alternate hypothesis (Ha) is the one that states that there is a statistically significant difference between the treatment group and the control group
58
G. Hardy, W. Weinberg determined the?
mathematical method for comparing the null hypothesis and the alternate hypothesis using measured/observed allele frequencies to look for evidence of evolution in a population
59
for Ho to be correct
gene pool must be stable and unchanging
60
for Ha to be correct
) gene pool frequencies are changing due to various processes of evolution (Ha = evolution occurring)
61
for Ho to be true which assumptions must be met?
``` No natural selection All parents survive All parents contribute equally to gene pool No genetic drift All alleles contribute exact frequencies (no “chance” changes) No gene flow No new alleles added or removed Random mating No sexual selection occurring No mutation No new alleles ```
62
what is the hardy weinburg equation?
p2 + 2pq + q2 = 1 | when all assumptions are met and Ho is true you use this
63
p
frequency of one allele (A1) in gene pool
64
p2
= p X p = frequency of homozygous genotype A1A1
65
q
= frequency of the other allele in gene pool
66
q2
= q X q = frequency of homozygous genotype A2A2
67
2pq =
frequency of A1A2 +frequency of A2A1 = all heterozygotes
68
The Hardy-Weinberg Principle
Both allele and genotype frequencies in a population will remain constant ~ in equilibrium ~ from one generation to the next unless specific disturbing influences are introduced
69
mechanisms of genetic change?
natural selection, genetic drift, gene flow, sexual selection and mutation
70
what are the natural selection "patterns found in populations?
Balancing Selection Directional Selection Stabilizing Selection Disruptive Selection
71
Balancing Selection
Diversifying, maintains polymorphism Due to “Heterozygous Advantage” of certain genes Heterozygotes have higher fitness than homozygotes Maintains genetic variation in populations Ex: sickle cell anemia (lab)
72
Directional Selection
Shift in the average phenotype ~ in one direction Selection event favors one extreme / one end of the bell-shaped curve
73
Stabilizing Selection
Selection event favors average phenotype Shift in width of bell-shaped curve Extreme phenotypes are at a disadvantage
74
Disruptive Selection
Selection favors the extreme phenotypes Eliminates average trait Increases genetic variation Sometimes leads to speciation
75
what are the braches of genetic change under natural selection?
Balancing Directional Stabilizing Disruptive
76
Founder Effect
When small number of individuals leave a source population and establish new population Allele frequencies differ from source population
77
Bottleneck Effect
A sudden reduction in number of alleles in a population | Ex: Natural disasters and population loss
78
females often select the mate in
sexual selection
79
• Synaptomorphy
a defining trait only found in one clade
80
what useful traits does male to male competition use?
o Weaponry o Strength o Body size
81
What traits do females look at when choosing a male?
o Beauty o Parenting skill o Nest o Resources
82
what are requirments for nat selection?
variation in the trait and the trait is heritable and theres compition for survival
83
central dogma
dna is transcribe to rna which is translated to protein and protein creates traits
84
homoglies of evolution
species, structural, developmental and genetic
85
species homology
identifiably group in appearance and habitat and behavior
86
structural homology
similar anatomy
87
developmental homology
similar embryonic structure
88
genetic homology
similar genes
89
gene linkage
gene on same chromosome
90
evolution by nat selection
change in the allele frequency in a population over time.
91
adaptation
the action or process of adapting
92
gene
a length of dna that codes for protien
93
genotype
an individuals collections of allleles
94
natural selection is the only mechanism that
makes an adaptive change
95
Phylogeny
evolutionary history of a group of organisms | summarized in a phylogenetic tree
96
Phylogenetic Tree
shows ancestor-descendant relationships
97
three assumptions of hardy weinburg
simple traits, random mating, mechanisms of genetic change
98
branch
a population through time
99
node
when ancestral population split into (2) or more descendants
100
terminal node
tip or endpoint of a branch
101
if there is not prezygotic isolation ad interbreeding occurs what are the outcomes?
hybridization, renforment of divergence and pop fusion
102
Genealogical relationships among species Based upon shared characteristics:
Morphology Behavior Development
103
Phenetic Approach
– focused on overall similarity; usually in morphology or observable traits; comes from “phenotype”
104
Cladistic Approach
focused on shared characteristics, shared ancestory; comes from “clade”
105
homology
Similar traits in two groups suggest a common ancestor
106
Homoplasy
Sometimes similar traits evolve independently in distantly related groups of organisms caused by “Convergent Evolution”
107
Adaptive Radiations
When a single lineage produces many descendants Descendants live in a variety of habitats Descendants find food in a variety of ways
108
Adaptive Radiations Produce a pattern in the tree of life called
Star Phylogeny
109
What triggers adaptive radiation events?
Ecological opportunity-new resorces | Morphological innovation-important new traits can develop

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