1
Q
Comparative vertebrate anatomy [Definition]
A
study of functional morphology of vertebrates
2
Q
Comparative vertebrate anatomy [Points]
A
- compares body form and function of various structures
- compares similarities and differences in morphology
- interprets similarities and differences in ancestry, function, and evolution
3
Q
Why study vertebrate morphology?
A
- learn and understand morphology
- advance human knowledge
- understand relationship between form and function
- to study evolution
- fascinating
4
Q
What is science?
A
- a way of knowing
2. a method of collecting information
5
Q
What are other ways of knowing?
A
- faith
- experience
- experience of others
6
Q
What is faith?
A
- a confident belief in the truth, value, or trustworthiness in a person, idea or thing
- that belief does not rest upon logical or scientific proof or material evidence
7
Q
What is experience?
A
active participation in events or activities leading to the accumulation of knowledge and skill
8
Q
Steps in the scientific method
A
- identification of a problem, ask a question
- defining the entity to be studied
- designing an experiment/ study
- obtaining a representative sample
- collect data by observing and measuring samples
- analyze data
- interprete data/ draw conclusions
- report methods
9
Q
Weaker methods of studies?
A
- correlation
- comparative studies
- historical studies
- modeling
10
Q
What is evolution?
A
- changes in gene frequency of a population through time
2. changes in character states of organisms through time
11
Q
Evolution requires:
A
- genetic variability
2. differences in ability to survive and reproduce being linked to differences in heritable genetic variation
12
Q
What is genetic variability?
A
ultimate source of variation is mutation
13
Q
What is natural selection?
A
differential reproduction and survival of organisms with certain character states or genotypes. Not survival of the fittest.
14
Q
How does natural selection work?
A
- more offspring is produce than can survive each generation
- population size exceeds the environments carrying capacity
- critical resources becomes limited
- competition occurs
- additive genetic variation in competitive ability exists
- best competitors survive and reproduce
- they are more fit
- fitness–relative number of offspring produced
- results in an increase in a frequency of the traits that increased fitness in the next generation
- if frequency of a given character state changes
- currenect generation—-natural selection
- next generation—-evolution
15
Q
Example of evolution by natural selection
A
- Poecilia reticulata—-common guppy
- live in Trinidad
- female prefer males with lots of coloration and high display rates
- populations occur in high and low predation habitats
i. high predation
a. males have reduced coloration and display behavior
b. natural selection is stronger than sexual selection
ii. low predation
a. males are brightly colored and have high display rates
b. sexual selection is stronger than natural - fish from high predation habitats were transferred to low predation habitats
- fish from low predation habitats were transferred to high predation habitats
- populations were assayed for their coloration and display behavior 3 years later about 9 to 12 generations
- low predatation guppies had lost most of its color and had reduced display rates
- high predatation guppies had increased in color and had increased display rates
- populations bred true in lab
16
Q
Evolution by Natural Selection
A
- adaptation is a process of a population becoming adjusted to a particular environment over many generations
- adaptive trait is a structure, a physiological mechanism, or behavior that increases the probability that an organism will survive to reproduce
- adaptive traits are not always inherited
- habitat dependent and will be for the current environment
- natural selection doesn’t evolve toward some predetermined goal
- genetic variability must exist
- individuals with certain gene combinations will be more fit [co-adaptive gene complex]
- different gene combinations may have the same fitness
- adaptations are not perfect vertebrate eye
17
Q
Kinds of selection
A
- Natural selection
- artificial selection
- sexual selection
18
Q
natural selection
A
differential survival of genotypes/phenotypes
19
Q
artificial selection
A
differential breeding of organisms with certain desirable traits by humans
20
Q
sexual selection
A
differential mating success
1. male male competition: structures that help males uptain resources/win fights 2. female choice
21
Q
forms of selection
A
- directional selection
- stabilizing selection
- disruptive selection
22
Q
directional selection
A
- selects for an extreme phenotype at one end of the distribution
- causes the traits distribution to shift
- mean, median , mode all change
- standard deviation may increase, decrease, or remain the same
23
Q
stabilizing selection
A
- tends to eliminate individuals at each end of the distribution
- selects for a mean value of a trait
- mean, median, mode are stationary
- standard deviation decreases
- adapted to local conditions and prevents change
24
Q
disruptive selection
A
- eliminates individuals with the mean character state
- selects for the two extreme forms
- mean may remain the same
- bimodal
- standard deviation increases
- assortative mating: one phenotype prefers to mate with that phenotype
- speciation arises: splitting of one species to more
25
assortative mating
one phenotype prefers to mate with that phenotype
26
speciation arises
splitting of one species to more
27
evidence for evolution
1. artificial selection
2. embryology
3. molecular
4. fossil record
5. biogeography
6. comparative anatomy
28
artificial selection
animal and plant breeding ex: domestic dogs
29
embryology
1. embryos of organisms tend to go through similar stages of development
2. examples
i. human embryos go through stage where they have gill slits and rudimentary tails
ii. traits in common with all vertebrate organisms: fish, amphibians, reptiles, birds
30
molecular
DNA, RNA, ATP, glycolysis, many similar enzymes indicate common decent
31
fossil record
sequential changes in the preserved remains of ancient life
32
biogeography
geographical distribution of related organisms
33
comparative anatomy [evidence of evolution]
1. unity of plan
2. permits classification of organisms
3. common ancestors
34
unity of plan
observation that organisms that are clearly different species have similar morphology
35
common ancestors
1. homologous
| 2. analogous
36
homologous
similarly constructed, structures with similar morphology resulting from a common ancestor
37
analogous
similar in function not in structure
38
evolutionary theory
1. phyletic gradualism
2. punctuated equilibrium
3. evolutionary trends
4. patterns of evolution
39
phyletic gradualism
1. species character states change by the slow, continuous accumulation of mutations favored by natural selection
2. habitats change slowly and organisms adapt to changes
40
punctuated equilibrium
1. species change very little in structure over time but when changes does occur it is rapid in geological time
2. descendants are clearly different from ancestors in form
41
evolutionary trends
1. within a phyletic line, adaptive changes progress in more or less the same direction
- a group of clearly related genera that change in a linear or branching fashion with the extinction of prior forms
2. patterns
i. small to large body size
ii. reduction in serial parts
iii. increasing the size of weapons
iv. decreasing number of skull bones in vertebrates
42
patterns of evolution
1. parallel evolution
2. divergent
3. convergent
43
parallel evolution
a change in 2 or more lineages so that given structures undergo similar changes in response to similar ecological conditions
44
divergent
1. a pattern where individual speciation events cause many branches in the evolution of a single group of related organisms due to different ecological conditions
2. can give rise to an adaptive radiation
- an evolutionary pattern in which there is a rapid increase in the number of kinds of closely related species
45
convergent
a pattern where unrelated groups or species show similar characteristics
46
speciation [points]
1. evolution is linear changes from one form into another
2. speciation
3. allopatric speciation
4. parapatric speciation
5. isolating mechanisms
47
speciation
1. process of generating new species
| 2. species
48
species
a group of interbreeding or potentially interbreeding organisms that are reproductively isolated from other similar organisms
49
allopatric speciation
1. generating new species in different geographic locations
2. barriers arise that separate gene pools
3. no gene flow between gene pools
4. differential selection, genetic drift and mutation within the different populations
5. barriers removed
6. two populations come in secondary contact
7. reproductive isolation
50
parapatric speciation
1. Cichlids in Lake Victoria may be dividing along color lines due to sensory changes caused by differences in light
2. fish shallow waters are bathed in bluer light
3. those in the turbid water [deeper water] bathed in redder light
4. shallow water fish have a visual pigment move sesitive to blue light
5. deep-dwelling fish have a visual pigment mroe sensitive to red light
6. DNA evidence indicates genetic divergence
7. suggests that the two groups aren't interbreeding
8. females in shallow water prefered blue hued males
9. females in deep water prefer red hued males
10. this differential female preference maybe causing speciation
51
isolating mechanisms
1. pre-zygotic
2. post-zygotic
3. speciation genes
52
pre-zygotic
1. mechanical isolation
2. gamete isolation
3. temporal isolation
4. behavioral isolation
5. sensory isolation
53
mechanical isolation
isolation due to the way an organism is built
54
gamete isolation
histocompatibility complex; sperm and egg don't recognize themselves
55
temporal isolation
isolation due to different breeding periods
56
behavioral isolation
isolation due to differences in mating behaviors
57
sensory isolation
isolation due to differences is sensitivity to environment ex: parapatric speciation
58
post-zygotic
1. hybrid inviability
| 2. hybrid sterility
59
hybrid inviability
hybrid between 2 species that are sickly
60
hybrid sterility
hybrid between 2 species that is infertile
61
speciation genes
1. genes for adaptation may also cause speciation
2. adaptation to one environment may be maladaptive in another environment and prevent or reduce breeding
3. eda gene in sicklebacks
4. eda gene is one of the genes that codes for armor
5. one form codes for heavily armored fish, thick plates
6. the other form codes for a light armor, thin plates
7. marine fish are heavily armored---defense against fish predators
8. stream fish are lightly armored---defense against insect predators
9. both types of fish can live in both fresh and marine habitats
10. but are unable to survive as well in the opposite habitat and are eliminated by natural selection before they can breed
Comparative Anatomy
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