Final Flashcards
1
Q
What are some major changes that influenced the theory of evolution since darwins time.
A
Punctuated equilibrium, altruism, sexual selection, phenotypic selection
2
Q
what is evolution
A
change over time, heritable changes in a population spread over many generations
3
Q
what are the forces of evolutionary change
A
Mutation, migration, Selection, Drift
4
Q
How does mutation affect genetic variation within populations and among populations?
A
within= increase, among= increase
5
Q
How does migration affect genetic variation within populations and among populations?
A
within= increase, among= increase
6
Q
How does selection affect genetic variation within populations and among populations?
A
within and among= diverging=decrease, balancing= increase
7
Q
How does drift affect genetic variation within populations and among populations?
A
within= decrease, among= decrease
8
Q
what types of natural selection maintain genetic variation?
A
mutation and migration
9
Q
which types of natural selection maintain genetic variation
A
balancing and frequency-dependent selection
10
Q
What are the effects of genetic variation of inbreeding
A
genetic variation is lowered within a population
11
Q
What are the effects on genetic variation of random mating
A
increased genetic variation
12
Q
What are the effects on genetic variation on non-random mating
A
decreased genetic variation
13
Q
How do we estimate evolutionary change using quantitative genetics
A
Hardy weinberg equilibrium (genotype frequencies) Mendalian genetics (phenotype)
14
Q
What determines the response to selection
A
heritability
15
Q
How is adaption defined?
A
a trait that increases the ability of an individual to survive or reproduce compared with individuals without the trait
16
Q
How can we test for adaption
A
experimental
floral spur length
observational
giraffe long necks
comparative
bats (testes size)
17
Q
How do we test for adaption at the molecular level?
A
change in gene frequencies
18
Q
What is the difference between sexual selection and natural selection
A
sexual selection acts on characteristics involved in mate choice and can trigger rapid divergence
Natural selection causes divergence based on food preferences, habitats used or other ecological differences
19
Q
How do we explain the evolution of traits that have no direct fitness benefit
A
inclusive fitness
20
Q
what is kin selection
A
selection based on reproductive success of relatives since they share genes
21
Q
What is hamiltons rule
A
rB>C, favors altrustic acts when indirect fitness benefits the reciever, reduced by the coefficient of relatedness, exceeds costs to altruist
22
Q
What is cladogenesis
A
creation of new lineages
23
Q
what is anagenesis
A
evolution within a lineage
24
Q
What is speciation
A
making of a new species through reproductive isolation
25
what is a species
group of interbreeding populations that are evolutionary independent of other populations
26
How should we recognize a species
Biologically ?
27
Name the 3 species concepts
morphospecies
biological species concept
phylogenic species concept
28
describe morphospecies
morphological differences and similarities
29
describe the biological species concept
group of interbreeding populations, reproductively isolated from others
30
describe the phylogenic species concept
use phylogeny to identify taxonomic groups
31
Which concept was proposed by Ernst Myer
biological species concept
32
What are the 3 steps of any speciation process
isolation
divergence
reproductive isolation
33
what is dispersal
movement of groups to a new place making a new population
34
what is vicariance
the splitting of a populations range causing 2 smaller sub-populations
35
Use the copepod Eurytemora to illustrate each method and its usefulness. Why is the Morphospecies concept misleading for Eurytemora? Describe the evidence.
the copepod is morphologically indistinguishable between each of the species making it impossible to identify this genus using the morphological concept
36
Consider the Hawaiian cricket and the snapping shrimp examples. Describe the evidence that supports dispersal as the mechanism in crickets, and vicariance in snapping shrimp.
The crickets you can follow the lineage that shows that the oldest crickets lived on the oldest island first and then the next oldest population on the next oldest island
The shrimp the 2 populations are the same age and pre-dated the closing off of the seaway
37
4. Which speciation mechanism is Ernst Myer known for?
Allopatric speciation
38
During speciation, what are the major forces cause divergence? Explain how genetic drift works as a possible cause of divergence.
drift
natural selection
sexual selection
drift works because in speciation you have, small populations starting out which it is very easy for drift to work and fix alleles early on
39
What caused divergence in sticklebacks? What is the evidence?
Natural selection
marine- armored shells
lakes- no armor, earlier reproductive times
40
5. What is secondary contact
When two populations that have diverged in isolation from a common ancestro are reunited geographically
41
what is reinforcement
selection for mutations that reduce hybrid matings
42
Explain the process of reinforcement, including a definition of prezygotic and postzygotic isolation.
Natural selection is increasing the reproductive isolation of a species to prevent interbreeding and creating of infertile or less fit offspring
Pre- reduce hybrid matings in the first place
Post- hybrid offspring is unfit in some way
43
Why is the fitness of hybrids important?
its driving the selection on the two parental species
44
What outcomes are possible, and how do they depend on the fitness of hybrids?
stable hybrid zone
assortative mating
high fitness of hybrid (creating an intermediate)
45
6. How does sexual selection lead to divergence? Explain the evidence for sexual selection as a likely explanation for speciation in cichlid fish in Lake Malawi.
sexual selection leads the females to choose males that had a similar color pattern for the most part, this is a form of non-random mating leading to divergence through assortative mating
46
Summarize the key difference in the way that natural selection and sexual selection lead to speciation?
NS uses some type of divergence event then reinforcement to lead to assortative mating rather than having assortative mating be the first step
47
7. How long ago did earth cool enough to be conducive to life?
~4bya
48
How old is life on earth?
~3.5bya
49
What is life?
evolvability,
| RNA or DNA genotype with protein phenotype
50
What are the 3 steps in the early chemistry of life?
inorganic molecules on earth
building blocks leading to polymers
cellularization
51
8. Describe the 2 earliest chemical traces of life.
```
oxidized iron (means seasonal photosynthesis)
chemical fossils graphite enriched C12 isotopes from living sources
```
52
Describe the earliest fossil evidence for eukaryotes.
stone mattress fossils 3-5bya
| eukaryote, nuclear membrane, increase in oxygen 2.0-1.5bya
53
How many years ago did
| unicellular life arise?
3-5bya
54
How many years ago did
Eukaryotic life?
2.0-1.5bya
55
How many years ago did
| Metazoan life?
565 mya
56
9. Why is the ribosomal RNA gene used to reconstruct ancient ancestors (LUCA)?
look at genes that code for ribosomal RNA because these genes show strong stabilizing selection, same function across all life
57
What was learned from a phylogeny of rRNA sequences?
Traditional 5-kingdom classification offers a misleading view on evolutionary relationships
3 major classes of life
prokaryotes are not monophyletic
not all protists are closely related
58
What was wrong with the classical 5 kingdoms of life?
archea are more closely related to eukaryotes than to true bacteria
59
10. Describe the rise of metazoan diversity from the beginning of the Cambrian period
rapid diversification of species, diverse forms, most phyla represented
60
What are the differences between the taxa and the diversity found in the Ediacaran and Burgess Shale fossils (consider body symmetry, number of tissue layers)?
many different lines of symmetry, and tissue layers, as well as evolving structures never seen before
61
11. Was the Cambrian radiation of diversity explosive or gradual?
explosive
62
Describe how the molecular clock helps to answer this question.
using a found fossil that is a LCA then you can find the amount of neural divergence between 2 taxa is related to time since the divergence
63
Describe the molecular evidence from two contrasting studies for the protostome/deuterostome divergence?
difference in times based on clock/phylogeny
64
Describe the molecular evidence from two contrasting studies for the radial/bilateral divergence?
615mya
65
Describe the molecular evidence from two contrasting studies for the
Echinoderm/chordate divergence?
1bya
| 526mya
66
12. What is adaptive radiation? What are two reasons that adaptive radiations occur? Give examples of each.
morphological divergence among many new lineages over a short period of time
darwins finches
mammals
67
13. What are the two major ideas for the tempo of morphological evolution? Explain each.
gradualism vs. punctuated evolution
68
Which tempo of evolution did Darwin envision? Why?
gradualism
| slow and gradual change over time
69
What is the pattern of morphological evolution seen in the bryozoans?
punctuated evolution (evolving into new niches)
70
14. What are mass extinctions?
The extinction of one of more species in a relatively short period of geological time, usually as a consequence of a catastrophic global event, a natural disaster, or an abrupt change in the environment, and based on studies of fossil records and macroscopic evidence.
71
How do they affect macroevolutionary patterns?
global, rapid, can create huge new niches for new species to thrive
72
What traits are associated with a greater likelihood of extinction?
specialized, concentrated, little variation
73
Describe the evidence from the lab that suggested the occurrence of species selection.
the most diverse and widespread species survived
74
15. Regarding the evolutionary history of biological diversity (cladogenesis and extinction), would you say biodiversity changes are typically rapid or slow? Gradual or punctuated? Give an example of each.
I would sat sod the most part it is slow over time unless there is a mass event there niches open up, then you can have rapid punctuated change
75
What is similar and different about adaptive radiation and punctuated equilibrium?
both have quick diversification, difference in the way the lineages happen, punctuated you have diversification, and then extinction of all but one or a few lineages
adaptive the species lineage stays the same until a rapid widespread divergence of many species, then long times of staying the same
76
Define species selection.
is the process responsible for the proliferation of species that have lower extinction and higher speciation rates
77
1. Outline the process of vicariance and how it shapes phylogenetic relationships between organisms. Relate this process to the relationship between South American and Australian marsupials.
vicariance: the formation of geographic barriers to dispersal and gene flow, resulting in separation of populations
78
2. Why do dispersal events "mess up" patterns of phylogenetic relationship expected given knowledge of vicariance? Use the curious case of the opossum to illustrate your answer.
clouds the relationship of ancestors with continental regions
79
3. Why are there more species at lower latitudes on Earth? Provide two hypotheses, and feel free to include one not covered by myself in lecture. For each hypothesis, state a prediction that could be tested experimentally.
geographic hypothesis
historical perturbation hypothesis
?more neutral environment?
80
4. Outline the equilibrium theory of island biogeography. In doing so, what two major forces are thought to counteract each other to determine the species number observed on islands.
geography will influence rates on immigration and extinction
distance to mainland influences immigration
island size influences extinction rate
81
6. Give one reason why speciation is only likely to occur on islands that are above a threshold size.
more available niches?
82
7. Describe two potential processes that explain why flightless birds evolve on islands. Is one of these processes also involved in the loss of anti-predator behaviors?
there are not normal preditors that require flight, flight is costly, stay on the group
more food resources, causes larger body mass, inability to fly
83
8. Why do many island lizards evolve "gigantic" body sizes? Describe an experiment to test this adaptive hypothesis.
small predators released from predation upon larger individuals on islands, can grow larger.
84
9. What specifically is wrong with the popular iconography/cartoon that shows the chimp evolving into a human? Did humans evolve from chimps?
only one in subfamily Homininae
there was not 1 hominid that evolved into modern humans, but rather many and we all coexisted one human variant is our ancestor
we have a common ancestor with chimps
85
10. Recall from the beginning of our semester that evolution is often viewed as “progressive”. Explain, using human evolution as an example, why evolution is not progressive.
loosing the MYA16 gene for jaw muscle was harmful for eating tubers
low diversity among those in population, occupy a small habitat range
86
11. Explain briefly the major events in the history of the family Hominidae. Was the family Hominidae successful? How did diversity change over the past 22 million years? Over what time interval did diversity decline dramatically?
we were the last species to leave and only one to survive,
87
12. When did different species of Homo coexist? When and how many times did species of the genus Homo leave Africa? Did they replace other hominids, or interbreed and share genes? What is the evidence for interbreeding?
70,000 mya
left africa at various times
some interbreeding
europeans share neanderthal genes
88
13. In what ways do you think humans provide a great illustration of macroevolutionary processes (cladogenesis and extinction)?
many different clades of hminids that all but one became extinct
89
14. Chimpanzees are our closest hominid ancestor, but did our last common ancestor look like chimps? How has extinction of hominins altered our view of the evolutionary history of humans?
no our LCA was probably more of a bipedal hominid
| by not having these species around we draw conclusions on that we can see
90
15. Describe how understanding evolution has helped in understanding drug therapy and the use of AZT to treat HIV. In the development of vaccines for HIV.
we know that diseases and parasites are changing over time which then er can concentrate efforts to target the new forms
drug targets reverse transcriptase but NS works on reverse transcriptase to then lead to AZT resistance
91
16. Why are novel antigenic combinations favored in flu virus? What form of selection acts on them? Why? As a result, are there more substitutions in synonymous or non-synonymous sites? What is the source of new genetic variants in some flu strains?
they escape immune detection
negative frequency dependent selection
nonsynomous sites?
bird human, and swine species pass influenza around creating pandemic forms
92
17. HIV is nearly 100% lethal to human hosts. Explain why HIV virus might harm their host so much. What, in general, are three reasons parasites harm their host?
coincident: by product of traits unrelated to the interaction
maximizes within-host growth
Maximizes between host transmission
93
18. Why might parasites evolve to be benign to their hosts?
to be passed on to multiply
94
Why might parasite evolve intermediate levels of virulence?
to multiply self
95
How does selection for within-host growth affect the evolution of parasite virulence?
increases pathogen growth
96
How does selection for between-host transmission affect the evolution of parasite virulence?
decreases pathogen growth
97
19. How do the details of transmission affect the evolution of virulence? Which type of parasite should have greater virulence: water-borne or directly transmitted? Directly transmitted or vector-mediated? Which depends on a healthy host for transmission?
all pathogens want to only make more of themselves
water-borne have greater virulence
vector borne have less virulence
98
20. Some parasites are vertically transmitted—from parent to offspring. Do you expect these parasite to have high or low virulence?
low virulence (direct contact transmission
99
21. Which source of selection seems to be responsible for the most phenotypic evolutionary change in animals, according to the review of studies of evolution by Darimont et al 2009: natural, human harvest, or other anthropogenic selection? What type of selection on quantitative traits does human harvest typically produce?
natural selection
| harvest selection
100
22. For cod and Atlantic silverside, what traits were favored by human harvest selection? Why were they favored? In what way was the harvest-large strategy in the silverside experiment detrimental to human interests?
large body size, feeds more people, the strategy was detrimental because it leads to having smaller fish, having to harvest more, over harvesting and then population reduction
101
23. What are the consequences of habitat conversion or loss for habitat area, habitat patch size, and patch isolation? How does habitat loss affect species diversity in remaining patches? Why? Do you expect a smaller species diversity in a small, distant habitat island, compared to a large, close habitat island?
small isolate populations
interbreeding, drift, allele fixation
the vortex of extinction
102
what is inclusive fitness
the sum of its classical fitness (how many of its own offspring it produces and supports) and the number of equivalents of its own offspring it can add to the population by supporting others
103
what is allopatric speciation
is speciation that occurs when biological populations of the same species become vicariant — isolated from each other to an extent that prevents or interferes with genetic interchange.
104
What is sympatric speciation
the process through which new species evolve from a single ancestral species while inhabiting the same geographic region.
