Exam 1 Flashcards
(138 cards)
1
Q
How did Charles Darwin describe evolution?
A
decent with modification
2
Q
Levels of organization
A
cells tissues organs organ system organism
3
Q
Evolution is both a … and a …
A
pattern, process
4
Q
Pattern
A
observations about natural world
5
Q
Process
A
mechanisms causing pattern of change
6
Q
How did Darwin’s ideas challenge traditional views?
A
Many thought the earth was young and that species were unchanging; perfectly matched to their environment
7
Q
Aristotle’s Csala Naturae
A
- Species do not change (they are designed by God and perfect) but there are some “affinities” among organisms
- Organisms are arranged on a ladder of increasing complexity (“scale of nature”)
8
Q
Species do not change (they are designed by God and perfect) but there are some “affinities” among organisms
A
Aristotle’s Scala Naturae
9
Q
Organisms are arranged on a ladder of increasing complexity (“scale of nature”)
A
Aristotle’s Scala Naturae
10
Q
Carolus Linnaeus
A
Developed binomial nomenclature
11
Q
Binomial nomenclature
A
two part naming system (Genus species)
12
Q
How did Carolus Linnaeus name organisms?
A
Based on physical characteristics (morphology) and did NOT describe/support evolutionary relationships
13
Q
What did Darwin argue that classification should reflect?
A
Evolutionary relationships
14
Q
Carolus Linnaeus’s classification system
A
species were grouped along with similar species into increasingly general categories
15
Q
Why did Linnaeus believe adaptations occurred?
A
the Creator had designed them for a purpose
16
Q
George Cuvier
A
Developed Paleontology
17
Q
Developed Paleontology
A
George Cuvier
18
Q
Paleontology
A
the study of fossils
19
Q
The older the strata (rock layer)…
A
the more dissimilar its fossils were to current life-forms
20
Q
What did Cuvier attribute extinctions to?
A
catastrophic events
21
Q
What did Cuvier speculate?
A
repopulation was by immigration (opposed evolution)
22
Q
What do some scientists believe?
A
great changes can happen via slow but continuous processes
23
Q
James Hutton and Charles Lyell
A
Geologists who stated that changes in Earth’s surface can result from slow continuous actions
24
Q
Geologists who stated that changes in Earth’s surface can result from slow continuous actions
A
James Hutton and Charles Lyell
25
What did Hutton determine?
The Earth is millions of years old (rather than a few thousand)
26
What ideas were Darwin's thinking influenced by?
1. Fossil record
| 2. Idea of slow and continuous processes producing biological changes (evolution)
27
Jean-Baptiste de Lamarck
French biologist
28
What did Jean-Baptiste de Lamarck suggest?
life evolves
29
what mechanism did Jean-Baptiste de Lamarck propose?
1. ) use and disuse
2. ) inheritance of acquired characteristics
3. ) innate drive for complexity
30
Use and disuse
the more you use, the stronger it becomes
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Inheritance of acquired characteristics
Lamarck thought traits were aquired over a lifetime and that they could be heritable
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Jean-Baptiste de Lamarck's hypothesis
was testable, but wrong
| followed the scientific process
33
Charles Darwin
English naturalist and geologist who was fixated on adaptation and speciation
34
Who was Charles Darwin protege of?
botanist John Henslow
35
Who heavily influenced Darwin?
Lyell and Hutton
36
HMS Beagle
Darwin collected speciments and record observations
37
What did Darwin observe on the HMS Beagle?
1. ) fossils resembled living species
| 2. ) living species resembled those from nearby regions
38
What did Darwin hypothesize?
species from S. America colonized the Galapagos and speciated on the islands
39
What did Darwin focus on?
Adaptations
40
Adaptation
inherited characteristics of organisms that enhance their survival and reproduction in specific environments
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What are adaptation and speciation explained by?
natural selection
42
Natural selection
individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits
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individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits
natural selection
44
Alfred Russel Wallace
independently came up with the idea of evolution by natural selection
45
Origin of Species by Means of Natural Selection
published by Darwin in 1859
46
published by Darwin in 1859
Origin of Species by Means of Natural Selection
47
What did Darwin's book explain?
unity and diversity of life, as well as match between organisms and environment
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Descent with modification
species gradually aquire modifications that fit them to current environment, which leads to diversification
49
species gradually aquire modifications that fit them to current environment, which leads to diversification
Descent with modification
50
What is the history of life like?
a branching tree from a common trunk (ancestor)
51
What are morphological gaps in the branching tree explained by?
extinctions
52
What is the crafted argument of Darwin's book?
1. Artificial selection by humans
| 2. Observations and inferences from nature
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Observation #1 from Darwin's argument
Members of a population vary in inherited traits (behaviors can be inherited as well)
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Artificial Selection
humans choose the traits in plants and animals that they want (i.e. dog breeds)
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Observation #2 from Darwin's argument
All species can produce more offspring than their environment can support, and many of these offspring fail to survive and reproduce
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Inference #1 from Darwin's argument
Individuals whose inherited traits give them a higher probability of surviving and reproducing tend to have more offspring
57
Inference #2 from Darwin's argument
This unequal ability of individuals to survive and reproduce will lead tot he accumulation of favorable traits in the population over generations
58
Conditions for natural selection according to Darwin (when occuring together, these conditions yield evolution b natural selection)
1. ) there must be a variation of traits in a population
2. ) variations must be heritable
3. ) different variants have different rates of survival
59
Examples of Natural Selection
1. Darwin's finches
2. Industrial melanism in the peppered moth (biston betularia)
3. Pathogen resistance to drug treatments
4. Pest resistance to insecticides (includes crop pest and disease vectors such as mosquitoes)
60
Darwin's finches
Studied finches on the Galapagos Islands, which experience huge yearly variation in rainfall
61
What else did Darwin study in regards to the finches?
beak size varies, and is genetically-controlled and heritable
62
What occured in the Galapagos Islands in 1976-78?
the islands experienced a drought that killed 85% of the finches
63
Explain why the beak sizes change
Finches eat smaller seeds during dry years, increasing the frequency of large seeds. This produced very strong selection for large beaked birds and some selection for really small beaked birds that were capable of eating very small seeds that most couldn't handle
This led to the offspring of the finches having larger average beak size
This led to the offspring of the finches having larger average beak size
64
Explain the peppered moth
The peppered moth has both a white form and a dark form. During the industrialization era, air pollution increased and there was soot all over the trees. The dark moths went from 1% to 98% of the population in 50 years. As pollution decreased, lichen began growing on the trees, which allowed the white peppered moth better camouflage
65
Describe pathogen resistance to drug treatments
Drug resistant bacteria are becoming more common because the bacteria that are resistant to prescribed antibiotics reproduce. The offspring will then also carry the trait that causes them to resist
66
Pest resistance to insecticides (includes crop pest and disease vectors such as mosquitoes)
rapid human-induced changes in the environment lead to strong selection and a faster rate of evolution than would otherwise occur
67
What does natural selection act on?
The individual
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At what level does evolution occur at?
the population level
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Evolution is not...
goal directed (it's chance), nor is it progressive
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Four types of data that documents pattern of evolution
1. Direct observations
2. Homology-similarity resulting from common ancestry
3. The fossil record
4. Biography
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Direct observations
Soapberry bug, MRSA
72
Soapberry bug
fed on native plants in Florida, fruits of each plant differs, bugs in S. Florida have long beaks, bugs in C. Florida have short beaks
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MRSA (Methicillin Resistant Staphylococcus aureus)
became resistant to penicillin, then methicillin. Antibiotic resistance spreads faster than antibiotics have been discovered
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Natural selection donly removes what?
Variation (does not create variation)
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Natural selection can only work with what?
existing variation of the population
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Homology
similarity resulting from common ancestry
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Homologous structures
anatomical resemblances that present variations on a strucural theme present in a common ancestor
78
Vestigial strucures
remnants of features that once served important functions in organism's ancestors
79
Convergent Evolution
independent evolution of similar features in different lineages (as opposed to resemblace due to homologies)
80
Analogous traits
similar function, but not common ancestry
81
Homologous traits
common ancestry, but not necessarily similar function
82
Allopatric speciation
Gene flow is interrupted or reduced when a population is divided into geographical subpopulations
83
Sympatric speciation
Speciation takes place in geographically overlapping population. Gene flow is reduced by factors other than geographic speciation
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How does allopatric speciation occur?
subpopulations evolve independently through mutation, natural selection, and genetic drift
85
Types of Allopatric speciation
1. Definition of barriers depends on the organism
2. When individuals colonize new areas
3. Reproductive isolation
86
How can reproductive isolation arise?
a by-product of genetic divergence
87
Microevolution
consists of changes in allele frequency in a population over time
88
Macroevolution
broad patterns of evolutionary changes above the species level
89
Speciation
process in which one species splits into two or more species
90
Speciation is the focal point of evolutionary theory and...
forms a conceptual bridge between micro and macro evolution
91
Species
Latin for "kind" or "appearance"
92
Hybrids
the offspring of crosses between members of different species
93
Biological species concept defines species as...
a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring
94
Aspects of biological species concept
1. Gene flow between populations holds a species together genetically
2. Reproductive isolation
95
Reproductive isolaltion
biological factors (barriers) that impede two species from producing viable, fertile offspring
96
Types of reproductive isolation
1. Prezygotic barriers
| 2. Postzygotic barriers
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Prezygotic barriers
"before the zygote" -block fertilization
98
Types of prezygotic barriers
1. Habitat isolation
2. Temporal isolation
3. Behavioral isolation
99
Habitat isolation
breed in different places in the same range
| - not isolated by obvious barrier; rarely encounter each other
100
Temporal isolation
breed during different times of the day, different seasons, or years
101
Behavioral isolation
courtship rituals and other behaviors enable mate recognition and prevent breeding
102
After Mating Attempt, Prior to Fertilization
1. Mechanical isolation
| 2. Gametic isolation
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Mechanical isolation
mating attempted, but morphological differences prevent completion
104
Gametic isolation
sperm of one species may not be able to fertilize the eggs of another species
105
Postzygotic barriers
"after the zygote" -contributes to reproductive isolation after formation of hybrid zygote
106
Types of postzygotic barriers
1. Reduced hybrid viability
2. Reduced hybrid fertility
3. Hybrid breakdown
107
Reduced hybrid viability
genes of different parent species interact in ways that impair development and survival
108
Reduced hybrid fertility
hybrid survives, but is steril
109
Hybrid breakdown
first generationviable and fertile, but when mate with each other or either parent species, offspring are feeble or sterile
110
Limitations to Biological Species Concept
1. cannot be bapplied to fossils
2. cannot be applied to asexual organisms
3. emphasizes absence of gene flow, but gene flow can occur between distinct species
111
Morphological species concept
defines species by strucural features
112
What does the morphological species apply to
1. sexual and asexual species
| 2. fossils
113
What does morphological species concept rely on?
subjective criteria (debatable)
114
Examples of subjective criteria
Monarch and Viceroy
115
Ecological species concept
defines species in terms of its ecological niche
116
Niche
species "role" in environment defined as the set of conditions in which a viable populaiton can be maintained
117
What does niche apply to?
sexual and asexual species
118
What does niche emphasize?
the role of disruptive selection
119
Regions with many geographic barriers typically have...
more species than do regions with fewer barriers
120
Reproductive isolation between populations generally...
increase as the distance between them increases
121
Reproductive barriers are...
biological in nature; physical separation is not a biological barrier
122
In sympatric speciation, gene flow is reduced by...
non-physical barriers such as polypoidy, sexual selection, and habitat differentiation
123
Polyploidy
the presence of extra sets of chromosomes due to accidents during cell division
124
What is polypoidy more common in?
Plants than animals
125
What can a polypoidy produce?
new biological species in sympatry within a single generation
126
Sexual selecion
can drive sympatric speciation if females are choosing mates based on physical characterists
127
Habitat differentiation
1. Sympatric speciation can also result from the appearance of new ecological niches
2. Sub population explloits a new habitat or resource not used by the parent population
128
Types of sympatric speciation
1. Polyploidy
2. Sexual selection
3. Habitat differentiation
129
In allopatric speciation...
geographic isolation restricts gene flow between populations
130
In sympatric speciation...
a reproductive barrier isolates a subset of a population without geographic separation from the parent species
131
Hybrid zone
a region in which members of different species mate and produce hybrids
132
What can a hybrid zone be?
a single band where adjacent species meet
133
What can changes in environmental conditions result in?
the relocation of existing hybrid zones or the production of novel hybrid zones
134
What can breeding between hybrids and parent species result in?
the transfer of alleles from one parent species to the other
135
Three possible outcomes when closely related species meet in a hybrid zone
1. Reinforcement
2. Fusion
3. Stability
136
Reinforcement
Strengthening of Reproduction Barriers
1. hybrids less fit
2. natural selection stregthens prezygotic barriers
3. overtime hybridization decreases
137
Fusion
1. Hybrids are as fit as parents
2. Can be substantial gene flow between species
3. If enough reproductive barriers are weakened and parent species can fuse into a single species
138
Stability
Hybrids continue to be produced because extensive gene flow from outside the hybrid zone can overwhelm selection for increased reproductive isolation inside the hybrid zone
