Midterm Flashcards
(219 cards)
1
Q
What are the three main questions in evolutionary thinking?
A
The unity of life, the diversity of life, the adaptation of life
2
Q
What is a unifying theory?
A
A theory that is testable, applies to all levels of biology, is model able, is forward thinking, is fundamental, and is applied
3
Q
Why is the history of biology important?
A
it is conflicting with many views of creationism
4
Q
What is the tree of life?
A
an evolutionary map describing the relationships between all species
5
Q
Why is the tree of life difficult to create?
A
Extinctions make for gaps in relations
6
Q
What are nodes in a phylogenetic tree?
A
Speciation points
7
Q
What do hatch marks mean in a phylogenetic tree?
A
All species to the right of the hatch mark share homologous characteristics
8
Q
What is homology?
A
Similarity from common ancestry
9
Q
What do changes in homologous traits indicate?
A
descent with modification (ex. cats, humans, whales, bats all have same structure of limbs)
10
Q
Does homology apply to vestigial traits?
A
Yes (ex. even snakes have hips)
11
Q
Does function = homology?
A
No. Independent evolution of a function often occurs
12
Q
What is convergent evolution?
A
Independent solutions to similar challenges (ex. certain desert plants gaining CAM photosynthesis)
13
Q
How does homology help map evolutionary lineage?
A
Identifying shared traits can help identify extant or extinct common ancestors
14
Q
What is molecular homology?
A
homology of genetics
15
Q
Why is molecular homology important?
A
Highly conserved genes can prove universal relationship and solve for early differentiation of life
16
Q
How did continental drift help solidify evolution?
A
close relatives on different continents originally seemed to be divine creation. Vicariance can now be seen to be a product of continental drift
17
Q
What are the 4 testable postulates?
A
Trait variation
variation in survival/reproduction
covariance between traits and fitness
inheritance of trait variation
18
Q
What does heritability allow for?
A
evolution via natural selection
19
Q
Does artificial selection still function of heritability?
A
yes
20
Q
How has the Anthropocene impacted evolution?
A
Rapid environmental change causes rapid evolution
21
Q
How do soapberry bugs change after the introduction of different fruits?
A
Beak lengths change to allow for bugs to specialize on different fruits
22
Q
What is an individual?
A
A physiologically integrated individual developed from a zygote
23
Q
What is a population?
A
A cohesive group of individuals
24
Q
What is the gene pool?
A
the collection of alleles in a population
25
What is a species?
Individuals that could potentially meet and reproduce
26
How does phenotype vary within a species?
from allelic recombination, gene flow, and mutation
27
What is phenomorphism?
Allelic differences
28
What is continuous phenotypic variation?
Phenotypic variation caused by expression being controlled by multiple loci.
29
How are variation and loci related?
The more loci there are, the more variation there will be
30
How does influenza interact with epithelial cells?
It interacts with glycoproteins, resulting in endocytosis
31
Why is influenza hard to vaccinate for?
It is complex, rapidly evolving, and differentiating
32
What is a promising method for developing a universal vaccine?
Attacking stem antibody CR9114
33
What are the reproductive differences between microbial vs multicellular organisms?
Microbial organisms produce rapid generations whereas multicellular organisms have high variance in offspring
34
Why is it difficult treatment targeting the CR9114 antibody?
CR9114 is highly exclusive and needs a perfect fit
35
What does inhibiting CR9114 do?
It prevents the fusion of vesicles containing new viral particles to the membrane
36
What are the two most likely vectors of SARS-COV2?
Pangolins and bats
37
Why was SARS-COV2 so dangerous?
it differentiated rapidly after 2020
38
How did the majority of SARS-COV2 variants die out?
Evolution to extinction
39
How did omicron differentiate?
It came from the trunk of the SARS-COV2 lineage, meaning immunocompromised individuals had harboured early strains, allowing for differentiation
40
Why do we study evolution?
To explain where we came from and where we're going
To undestand and protect biotic diversity
To recognize significance of variation between species and within populations
To engineer new products and tools
41
How is evolution a unifying theory?
Because biology doesn't make sense without evolution
42
What evidence is there for evolution?
Historical, experimental, contemporary, fossils, homologies, analogies, vestiges, biogeography, and direct observation (disease, artificial selection, and adaptation).
43
What is one of the best examples of evolution in agriculture?
Brassica Oleacea. The wild mustard being bred to exhibit specific traits led to broccoli, kale, cabbage, wok choi, brussel sprouts, ets...
44
Can a phenotype appear outside of the ancestral range in artificial selection?
Yes, when mendelian genetics are more complex.
45
Can a trait hit an evolutionary max?
Yes, in simpler traits.
46
What did the corn experiment in illinois show?
The oil content of corn can go far beyond ancestral ranges, showing that multigenic traits can go beyond ancestral ranges, but simple traits can't
47
What is phenotypic plasticity?
Adaption to the environment
48
What is evolution?
Descent with modification
49
What is descent with modification?
The idea that living species are descendants of ancestral species that were different from the present day ones. The change in genetic composition of a population from gen to gen
50
Which greek philosopher proposed animals are perfect and permanent?
Aristotle
51
Who was Carolus Linnaeus?
A Swedish physician and botanist who sought to classify life's diversity. Developed the binomial system and used a nested classification going from general to specific.
52
Why are fossils important?
They are traces of organisms from the past found in sedimentary rock, which is formed from compression. This shows the organisms alive at the time that the sediment formed
53
How did Hutton and Lyell influence Darwin's thoughts on evolution?
They proposed the idea of large change through gradual processes
54
What is Lamarck's hypothesis of evolution?
That there is use and disuse of traits. Some traits become stronger through use, and some disappear. And there Is inheritance of acquired traits. Organisms can pass on the modifications made to their offspring
55
In. what ways was Lamarck correct and incorrect?
He had the idea of gradual change over time correct, but his mechanism was wrong. Acquired traits are not heritable
56
What was Cuvier's observations in regards to strata?
The older the strata, the more dissimilar the life forms were to current life forms. Some species appear, while others disappear. He explained that the disappearance and reappearance of species resulted from extinction events and immigration.
57
How is evolution supported by drug-resistant bacteria?
The use of antibiotics has allowed for the selection of antibiotic resistant genes. This results in these genes gradually becoming the dominant phenotype.
58
How do homologous traits support evolution?
They show common ancestry and divergence
59
Why is evolution only a theory?
Aspects such as speed of evolution are still being criticized. Natural selection isn't the only aspect involved in speciation.
60
What is sampling error?
Random bias due to small sample size
61
What is a Founder Effect?
When a population is founded from a small number of individuals from a different population
62
What is a population bottleneck?
When a population crashes and regrows, the alleles are not representative of the old population.
63
What is Genetic Drift?
Individuals make uneven contributions too the next generation, resulting in allele flux. The smaller the population, the more drift there will be.
64
What is Gene Flow?
The movement of genes between populations. Reduces genetic differentiation. Doesn't take much to preserve variation.
65
What is phenotypic selection?
The connection between phenotypic variation and fitness
66
What is directional selection?
Shifts the overall population makeup by favouring a more extreme variant
67
What is stabilizing selection?
Removes extreme variants and preserves intermediate variants. Ex. large and small babies die so stabilizing selection has produced more intermediate weights
68
What is disruptive selection?
Selection that favours extreme variants. Ex. Darwin's Finches
69
What would be the genotype in a population without variation in fitness?
HWE
70
Why is HWE unrealistic?
Sexual selection exists and causes sexual dimorphism
71
What is ornamentation indicative of?
High genetic quality, high fitness, high access to resources.
72
What were Darwin's big ideas?
Variation among individuals in breeding groups
Variation influences survival and reproductive fitness
If variation is heritable then subsequent generations will be better adapted than their forebearers.
73
How long had Darwin been sitting on the theory when Alfred Russell Wallace wrote to him?
20 years
74
What was the problem with variance?
Darwin didn't understand genetics and Mendel only kinda understood genetics
75
What is HWE
Genotype and Gene Frequencies are constant unless something is changing. p^2+2pq+q^2=1. Requires no mutations, immigrations, selection. Requires large randomly mating population.
76
What is the modern synthesis?
Darwin+Mendel. microevolution to macroevolution.
77
How is adaption explained?
Microevolution
78
What is the driving force of evolution?
Natural selection upon phenotypes
79
How is environmental stability related to parent offspring similarity?
Stability promotes greater parent offspring similarity
80
What happened in the drought of 77?
In Daphne Major a drought caused the availability of seeds to change, resulting in more hardy seeds, meaning bigger-beaked birds survived. R^2 between parents and offspring was 0.6
81
What are plasmodium?
The parasites that cause malaria
82
When did malaria originate in the human population?
100 000 years ago
83
What is the relationship between community and Malaria?
Community gives mosquitoes and parasites the perfect opportunity to thrive
84
What type of organism is plasmodium?
A single-celled eukaryote
85
How do plasmodium enter humans?
Through mosquito bites
86
What is the first area of the body that plasmodium target?
The liver. they breed in liver cells and then lyse them, entering the blood as merozoites
87
What do plasmodium do in the blood?
They breed in RBC, release gametocytes, fertilize an egg which the mosquito sucks in
88
What do plasmodium do in the mosquito?
A zygote is formed and becomes and oocyte, which then releases sporozoite.
89
What is microevolution?
Evolutionary change below the species level; change in allele frequencies in a population over generations/
90
What is genetic variation?
Differences among individuals in the composition of they genes or other DNA segments
91
How is genetic variation at the whole-gene level quantified?
As the average percentage of loci that are heterozygous.
92
Why does genetic variation at a molecular level usually not result in phenotypic variation.
Much variation occurs within introns
93
What is phenotype the product of?
The inherited genotype and many environmental influences.
94
Can non-genetically determined phenotype have evolutionary consequences?
No
95
What are the sources of genetic variation?
Formation of new alleles, alterations in gene number or positions, Rapid Reproduction. Sexual Reproduction.
96
How are new alleles formed?
By mutation
97
How do harmful mutations persist in diploid organisms?
The remain hidden by a dominant allele, allowing from propogation
98
What is neutral variation?
Variation with no advantage or disadvantage
99
In what type of cells can mutations occur that can be passed on to offspring?
In cell lines that produce gametes
100
How do increases in Gene numbers or positions occur?
Errors in Meiosis
101
How does rapid reproduction allow for more variation?
Allows mutations to accumulate faster
102
How does sexual reproduction allow for variation?
Many combinations of alleles exist, along with crossing over and random fertilization
103
What are the forces of non-equilibrium?
Geme flow, fitness difference, non-random mating, genetic drift
104
What are thalassemias?
Autosomal recessive disorders affecting both alpha and beta chains of haemoglobin. Point mutations and deletions. Homozygous have anaemia
105
What is sickle-cell anaemia?
A change from glutamic acid to valine at position 6/146 in haemoglobin leads to sickling
106
How are anaemias beneficial in areas at risk for malaria?
Heterozygous allows for resistance as the plasmodium cannot complete its lifecycle
107
What is responsible for the majority of the complexity in organisms?
Sexual reproduction
108
What is the most complex non-eukaryote?
Bacterial mats
109
What is the last asexual animal?
bdelloids rotifer
110
How do bdelloids share genes?
Through membrane
111
What indicates that sex is ancient and inherent?
Key sexual genes are present in every eukaryote and are basal
112
What is the only thing more ancient than sex in eukaryotes?
The mitochondria
113
How does stress drive sexual reproduction?
Through ROS
114
What does isogamous mean?
Gametes are equal size
115
What does anisogamous mean?
Gametes are unequal sizes
116
What are the benefits of small gametes?
Increased motility, increased numbers, higher probability of encounter
117
What are the benefits of large gametes?
increased probability of survival
118
What are the detriments of small gametes?
Decreased probability of survival
119
What are the detriments of large gametes?
Decreased motility decreased numbers
120
What are the benefits of mating types?
It acts as a check on inbreeding and allows for increased variation
121
What is problematic about sexual reproduction?
Mitochondria are competitive, very inefficient, low prob. of fertilization, direct conflict and injury in mating, missed opportunities for survival activities, increased predation risk., STDs, competition for mates, antagonistic genes
122
What are the benefits of sexual reproduction?
Novel genetic combinations, favourable allele combinations
123
What happens to mitochondria in clonal reproduction?
The best mitochondria prosper
124
What is selected for in mitochondria in sexual reproduction?
Docility of the mitochondria
125
What are the two main factors that drive differences in sex due to anisogamy?
Offspring care and energy requirements and the mating system
126
Why doesn't ornamentation make sense in natural selection?
It leads to decreased survival, uses increased energy, leads to increased predation
127
What is intrasexual selection?
same-sex combat
128
What is intersexual selection?
Mate choice
129
What was sexual selection critiqued?
Victorians believed in female passivity and that sexual differences were just female inferiority
130
How does the number of sexual partners impact offspring for males?
increased offspring
131
How does the number of sexual partners impact offspring for females?
No change in number of offspring
132
What is Bateman's principle?
Males have increased variance in the number of mates than females, creating correlation between number of mates and reproductive success
133
Why are females choosier about mates than males?
They put more energy into gametes and into offspring care
134
What did Trivers hypothesize?
animal behaviours result from which sex invests more into reproduction (sex that is the limiting resource invests the most offspring into reproduction, and the other sex is more opportunistic)
135
In what cases are males choosier?
When males invest energy into raising offspring and creating a nest
136
What is odd about the case of the stickleback?
Males do literally everything
137
What can be inferred about evolution from sexual selection?
The choosier sex drives evolution
138
What is a species?
A group of populations who have the potential to breed and produce viable offspring in nature, not just in a lab. Offspring must be fertile?
139
What is a pre-zygotic barrier?
A barrier to the formation of a zygote
140
What is a post-zygotic barrier?
A barrier that prevents the viability of offspring
141
What are the three species concepts?
Morphological, phylogenetic, and ecological
142
What are the phases of speciation?
Separation, divergence, and reproductive isolation. (mutations diverge, gene flow converges, and drift diverges)
143
What is allopatric speciation?
A true barrier between poulations
144
What is sympatric speciation?
Not true separation
145
What is dispersal?
Founders move away from population
146
What is vicariance?
Geography evolves to separate
147
How does sympatric speciation occur?
Specialization based on different resources
148
How much genetic change is needed for speciation?
Very little. Even one gene change can result in 2 species
149
What results in rapid speciation?
Meiotic errors
150
What is fusion?
The collapse of reproductive isolation
151
What is stability?
Good progeny
152
What is reinforcement?
Poor viability of progeny
153
How did life come about?
inorganic->organic->self-replicating organic->aggregates->progenotes
154
How did the first eukaryote come about?
Progenotes gave rise to LUCA, bacteria arose, archaea arose, archaea encapsulated DNA, genetic separated from the rest of the cell, FECA, protists, endosymbiosis
155
How did protists evolve into plants, animals, and fungi?
Evolved into opisthokont, which evolved into fungi and metazoa, and evolved into photosynthetic organisms like plants
156
How any times did plants colonize land?
Only once
157
What did early plants use for nutrients?
Symbiotic fungi
158
When did animals colonize land?
After plants, as they were reliant on them for survival
159
What is the fossil record?
Mineralized and frozen remains of organisms that we can date using C-14 ratio. The ecology is inferred by the contewxt
160
What percentage of species are extinct?
99%
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What is the rate of change of populations with respect to time?
births-deaths/t
162
How would one determine the number of species alive?
of speciation events - # of extinction events
163
What did continental vicariance cause?
Rapid speciation, new habitats, extinctions
164
What are mass extinctions?
Periods of great extinction cause by rapid environmental change
165
What is the 6th mass extinction being caused by?
Humans
166
What is adaptive radiation?
A period of rapid evolutionary change where organisms form many new species in order to fill ecological niches
167
What causes changes in phenotypes?
Differences in gene regulation and expression
168
How do complex traits evolve?
From multiple genes, independently
169
Is evolution goal-oriented?
No. Branching is speciation, pruning is extinction
170
What is taxonomy?
A hierarchal classification
171
How were early trees constructed?
Appearence
172
Can an extant species evolve from another extant species?
No
173
Do primitive species exist?
No
174
what does monophyletic mean?
All members of group share a common ancestor, and all lineages that share a common ancestor are in that group
175
What does paraphyletic mean?
All share a common ancestor, but not all lineages are represented
176
What does polyphyletic mean?
Members don't necessarily share a recent common ancestor
177
How are trees built?
From homologous characters
178
What is the outgroup?
A group used to polarize the others. Least similarity.
179
How can DNA, RNA, and proteins be used to determine relationships?
Slow mutation rate shows early evolution and divergene
180
What is parsimony?
Simple is best. The tree that requires the fewest character state changes in the one that most likely happened
181
What is a cladogram?
A tree that shows a sequence of events
182
What is a phylogram?
A tree where branch length is proportional to genetic change
183
What is the molecular clock?
DNA sequences attain mutations at a steady rate, so divergence occurs regularly.
184
Can hydrophilic signals be dissolved in aqueous fluids?
yes
185
Can hydrophobic signals be dissolved in aqueous fluids?
No
186
187
When can hydrophobic signals be released from cells?
Whenever they get a signal
188
How do hydrophobic signals travel through plasma?
They require a carrier protein
189
How do hydrophilic signals interact with a cell?
They bind to an external signal in order to elicit a response
190
What are hydrophobic signal receptors found?
Inside the cell
191
How do water soluble signals bring about a response?
By a signal cascade
192
How do lipid soluble signals bring about a response
By directly influencing trasncri[ption and trasnlation
193
Are protein factors water soluble?
Yes
194
What are factors that travel through the blood called?
Hormones
195
What are the elements ofn endocrine signalling pathway?
Synthesis, secretion, transport, reception, transduction, response
196
What is synthesis?
The process through which a ligand is synthesized in an endocrine gland
197
What is secretion?
The process through which a ligand escapes the tissue
198
What is transport?
The process through which the ligand makes its way to its target tissue
199
What is reception
The binding of a ligand to its target receptor
200
What is transduction?
The connection of a receptor to an effector
201
What is the response?
The ultimate consequence of a signalling cascade
202
What are the two protein carriers?
Albumin or globulin
203
What happens to the receptor after binding?
Conformational change that promotes trasnduction. Ex enzyme function or better docking site.
204
How are receptors specific?
They only bind to things that resemble the natural ligand
205
How do receptors alter their sensitivity to hormones?
By changing affinity or changing how many of them there are
206
What are mimetic?
compounds with structural similarities to ligands
207
What are agonists?
Mimetics that trigger the same response
208
What are antagonists?
Mimetics that block the natural ligand from binding
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What is phytoestrogen?
A mimetic that resembles estrogen in plants. it inhibits or activates estrogen products
210
What are all receptors comprised of?
Proteins
211
What are antagonistic hormones?
Hormones tha thave opposite functions
212
What are tropic hormones?
Hormones that regulate the levels of other hormones
213
What are exocrine glands?
Glands that secrete their products outside of the body
214
What are endocrine glands?
Glands that secrete their product within the body
215
What is the hypothalamus?
A collection of neurons organized into nuclei with dendrites that receive and axons that send
216
What is the posterior pituitary?
A collection of termini of axons coming from the hypothalamus. Secretions are made in the hypothalamus and capillary beds in pituitary are used to send hormones to the rest of the body
217
What is the anterior pituitary?
A region of the gland that communicates with the hypothalamus via portal vessels. Tropic hormones from hypothalamus cause the anterior pituitary to release pituitary hormones
218
What is the adrenal gland?
A gland where the medulla releases catecholamines and the cortec releases steroids
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