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BIOL 103 Module 1 > CourseCram Information > Flashcards

CourseCram Information Flashcards

1
Q

what is evolution?

A

the accumulation over time of inherited changes in populations leading to species which are related

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2
Q

what is Darwiian fitness?

A

an individual’s ability to survive and reproduce

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3
Q

what is an adaptation?

A

an evolved feature that enhances an organism’s fitness

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4
Q

what is a population?

A

a group of organisms of a single species living in the same geographical area

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5
Q

what is a species?

A

a group of organisms with a common ancestry and physical structures that are able to breed and have fertile offspring

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6
Q

what is a community?

A

a group of populations composed of organisms with common ancestry, sharing similae structures, functions, behaviours, and are able to interbreed in nature

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7
Q

what is an ecosystem?

A

an interactive system composed of one or more communities and their abiotic environment

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8
Q

what is a biosphere?

A

all of earth’s ecosystems considered together

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9
Q

what does the darwinian revolution differ from? and how

A
  • differs from essentialism
  • essentialism believes that organisms are created in species form
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10
Q

what is differential reproductive success?

A

if selected for, more likely to have babies that will survive

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11
Q

does survival immediately mean reproductive success?

A

no

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12
Q

what is the smallest unit that can evolve?

A

a population

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13
Q

populations evolve while individuals _____?

A

adapt

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14
Q

how was natural selection developed as a theory? what were the four observations

A
  • variation in phenotype exists among individuals
  • high reproductive potential means populations increase (for fittest) geometrically
  • individuals compete for limited resources
  • “fit” offspring with characteristics matching current environments are more likely to survivde and reproduce
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15
Q

what is the evidence for evolution?

A
  • fossil records
  • comparative anatomy
  • biogeography
  • comparative embroyolgy
  • molecular biology phylogenetics
  • convergent evolution
  • anthropocene infleunces
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16
Q

what are fossil records? describe.

A
  • allows one to observe the evolution from common ancestors to current living organisms
  • date by radioactive isotopes (c14)
  • limitation: many organisms don’t keave good fossils
  • limitation: many environments are good at preserving fossilization
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17
Q

what is comparative anatomy? describe.

A
  • reveals the existence of homologous structures beneath phenotypicaly different charactersm which indicates shared origin
  • limitation: similar function does not mean homology, and a threat to this thought is analgous structures (ex. bird wing vs bat wing)
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18
Q

what is “evo-devo”?

A

comparative embryology

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19
Q

what is comparative embryology?

A
  • patterns of homology that aren’t really seen until early development
  • organisms that share a common ancestor but were subjected to different selection pressures during alduthood were shaped different in their adult structures, but share common embyological stages
  • ex. gill ridges in human embryos as evidence that humans evolved from aquatic ancestor
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20
Q

what is molecular biology? describe

A
  • it is the best way to look at evolutionary history
  • the fact that all living organisms share the same building blocks (ex. DNA) it is a strong support for the idea that all living organisms share a common ancestor
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21
Q

where is evolutionary history reflected?

A

in DNA

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22
Q

what is phylogenetics? describe.

A
  • species that are grouped according to homolgous features that have shared evolutionary origins
  • “bifrocating tree”
  • we do not evolve into, but have a shared ancestory
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23
Q

what is convergent evolution?

A
  • the addition of the same biological trait in different lineages
  • complicates ancestory
  • have the same answer to different evolutionary problems, which gives rise to analagous structures
  • therefore you have to look at DNA to solve the problem of if they are different species
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24
Q

what is anthropocene influences? describe.

A
  • artifical selection: created a new species from a particular ancestory by selecting the best variats in the population for further breeding
  • humans caused evolutionary change through selective breeding, antibiotic resistence, etc.
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25
Q

describe the case study of “Soapberry Bugs”.

A
  • flat podded golden rain fruit was introduced to the species
  • natural selection existed in bugs with shorter beaks, that was favoured for this new introduction
  • and variation presisted in the lab
  • which meant that genetic change had occured, and was a product of evolution (meaning it was heritable)
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26
Q

what has to be present in order for life to evolve?

A

macromolecules

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27
Q

what was the chain for the evolution of planet?

A

inorganic molecules, organic molecules, self replicating organic molecules (RNA), aggregations (phospholipids), and progenote

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28
Q

where did archae arise from, and from that what arose?

A

from eubacteria arose archaea and eventually the first eukaroyte

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29
Q

what can natural selection act on?

A

heritable material

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30
Q

where did mitochondria evolve from?

A

intracellular parasitic bacteria, which describes why it is a very efficient metabolizer

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31
Q

where did the large diveristy of a protist arise from?

A
  • from serial endosymbiosis
  • brought about the ensymbiotic hypothesis: a class of hypotheses that view various organelles in eukaryotic cells as descendants of endosymbionts, (mitochondria, nucleus, chloroplasts)
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32
Q

what is the key evidence in the endosymbiotic hypothesis?

A

DNA sequencing shows a relationship between mitochondria, chloroplasts, and cyanobacteria

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33
Q

how are mitochondria passed down

A

via the egg

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34
Q

what are the two forms of macroevolution?

A
  • gradualism
  • punctuated equilibrium
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35
Q

what is gradualism?

A

the product of microevolution and adaptive divergence along very long periods of time, it is a constant pace of evolution, and it is very unlikely to be the entire full story

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36
Q

what is punctuated equilibrium?

A
  • when evolution is not gradual
  • very long and relatively stasis periods of time, interrupted by short intervals of intensive species turnover
  • these episodes often include explosive adaptive radiations and cases of mass extinction
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37
Q

which is more likely to occur, gradualism or punctuated equilibrium?

A

puntuated equilbrium
* fossil records show evolution is not gradual, happens in bits

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38
Q

when do adaptive radiations occur? what does this cause

A
  • rapid genetic change
  • occur because of the apperance of a novel characteristic that opens a new adaptive zone (new set of environmental resources to be used)
  • usually follow mass extinctions
  • occupants will have to re adapt to the environment
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39
Q

what are mechanisms that promote punctuated equilibrium on a smaller scale?

A
  • signifigant genetic changes in an organism from one generation to another
  • ex. small pop + new environment = adaptive evolution which is bottleneck or founder effect
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40
Q

what are some advantages and disadvantages of multicellularity?

A

Advantages
* specialization into epithelial, connective, muscle, and nervous tissues
* allows an increase in size

Disadvantages
* requires communication
* requires attachment
* requires the ability to turn on and off genes
* requires genetic commitment (once you specialize, you never go back)
* an increase in size also causes a need for transport, storage, etc

41
Q

what was the cambrian explosion? what did it result in?

A
  • earth erupted into many new organisms
  • this was the first appearance of anthropods
  • the first appearance of organisms with modern day body plans
42
Q

where did plants most likely arise from?

A

protists related to the modern day green algae

43
Q

what are the key features of plants?

A
  • vascularization: allows movements of nutrients and wastee
  • seeds (gymno vs angio): allows the distribution of offspring
44
Q

describe what plants colonization of land was like

A
  • had to be able to maintain structure without the buoyancy of water
  • only one aquatic protist lineage was able to successfully colonize land
  • likely was a streptophyte algae
  • then the anthropods followed
  • then the land vertebrates followed (a new niche opened up)
45
Q

what is the cause of mass extinction, and when does it occur?

A
  • occurs when there is a cascade of biotic (ex. bacteria die off) and abiotic (ex. volcanic eruptions, acid oceans, etc) factors that decrease species diveristy
46
Q

what is a benefit for mass extinction?

A
  • opens up niches for adaptive radiation
  • and causes a shift in the diveristy of life
47
Q

what do extinctions clear out?

A

niches

48
Q

what does extinctions cause an opportunity for?

A

rapid expansion and radiation

49
Q

what is the role of adaptive radiation after extinction?

A

period of evolutionary change in which groups of organisms form many new species whose adaptation allow them to fill different ecological roles

50
Q

what is the order of events after extinction?

A

extinction—- radiation—- speciation

51
Q

what type of genes cause morphological diveristy?

A

regulatory

52
Q

what is heterochrony?

A

genes that change the timing of development
* example: paedomorphosis (maintaining juvenile form)

53
Q

what are the other mechanisms of evolution, besides natural selection?

A
  • sexual selection: strong selective force, very similar to natural selection in the size of its force
  • genetic drift: strong in small populations
  • random mutations: ultimate source of variation
  • gene flow: reduces drift between populations
54
Q

what are the 3 types of genetic variation?

A
  • mutations
  • sexual reproduction
  • balanced polymorphism
55
Q

what are mutations and their relevance to genetic variation?

A
  • changes in DNA sequences that leads to new alleles that, if naturally selected for, take over the gene pool
  • an example of this is antibiotic resistance
56
Q

what acts first, variation or selection?

A

goes variation then selection for that favourable trait

57
Q

describe the case study of antiobitic reistance. What type of genetic variation is it?

A
  • mutation
  • bacteria has a high reproduction rate, high rate of genetic exchange, and a strong selection pressure
  • antiobiotic resistance is acquired through: mutations and horizontal gene transfer
  • resistance already exists, but selection pressure is added with antibiotics
  • resistance is lost thorugh antibiotic use
  • the fastest wat to encourage resistance is when you don’t finish antiobiotics
    HGT
  • conjugation: passing DNA between cells
  • transformation: free DNA
  • transduction: phage
58
Q

how is sexual reproduction a source of genetic variation?

A
  • random mating
  • random segregation of parental chromosomes in meiosis
  • meiotic recombination through crossing over
59
Q

how is sexual reproduction a source of genetic variation?

A
  • random mating
  • random segregation of parental chromosomes in meiosis
  • meiotic recombination through crossing over
60
Q

when is sexual selection vs asexual selection favoured over the other?

A

sexual
* if the environment is unpredictable
* if your genes aren’t food

Asexual
* if your genes are good

61
Q

what is polymorphism?

A

many alleles/phenotypes for one gene

62
Q

what can lack of variation lead to?

A

extinction

63
Q

what is balanced polymorphism?

A

the active maintenance of variation in a population

64
Q

what are some of the sources of balanced polymorphism?

A
  • diploidy: hides variation in the form of recessive, incomplete dominant, or co dominant alleles in heterzygotes
  • patchy environments: adaptive maintenance of variation
  • frequency dependent selection: usually happens a lot with sexual reproduction, when a specific phenotype becomes very frequent, the environment can adapt to it
  • heterozygote advantage: maintains variation, especially needed in changing environments to survive (think sickle cell)
65
Q

What is the hardy weinberg equilibrium?

A
  • the genetic structure of a population remains constants generation after generation in the hardy weinberg equilibrium unless acted upon by agents other than sexual recomination
  • measures the frequency of alleles in population
  • p+q=1 and p^2 + 2pq +q^2 =1
  • p= frequency of allele one
  • q=frequency of allele two
  • p^2= frequency of homozygous dominant genotype
  • 2pq= frequency of heterozygous recessive genotype
  • q^2= frequency of homozygous recessive genotype
66
Q

how does hardy weinberg equilbria relate to evolution?

A

if the genetic structure of a population deviates from the equilbria, population is evolving

67
Q

what are the forces of micro-evolution (small time scale)?

A
  • non random mating( assortative mating and inbreeding) depression
  • genetic drift
  • gene flow
  • natural selection
68
Q

what is non random mating?

A
  • selective
  • when organisms do not have equal chances of mating based on their genotype
  • assortative mating: (ex. short prefers short), can result in change in allele and genotype frequencies, reduces frequency of heterozygous
  • inbreeding depression: refers to low fitness in inbred individuals due to increased homozygosity for rare defects, in a small population this increases
69
Q

what is genetic drift?

A
  • has something to do with sampling error (not getting the full picture with a small pop)
  • two types of drift: bottleneck and founder effect
  • bottleneck: same place
  • founder: new place
  • the two types of drift are common sampling error types that cause non selective drift, and don’t originate from changes in fitness
70
Q

describe the case study of the greater prairie chickens, the type of drift it is, etc.

A
  • bottleneck
  • pop. shrank from humans
  • importation of stock from neighboring states led to habitat destruction
  • conservation efforts tried to max. gene flow (bridge the population to reduce bottleneck) between potentially isolated species and increase genetic variation
71
Q

describe the case study of the afrikanner’s and the type of drift it is.

A
  • founder effect
  • hunnington’s disease is abnormally high due to the founder effect
  • 1/3 white south africans from about 40 founder
  • 50% of 2.5 million poopulation have 20 names traceable to that ship
72
Q

what is gene flow? explain

A
  • gene flow mixes alleles among populations of the same species
  • important to maintaing variation
  • most gene flow is over short distances
  • rare long distance gene flow may also be important to maintain genetic vatiation (conservation biology)
73
Q

what is natural selection?

A
  • it is not evolution, but can lead to it
  • fitness= survival + reproductive success
  • the process by which an organism is better adapted to the environment and has a higher chance of leaving more offspring
  • out of all of the cases of microevolution, only natural selection generally adapts a population to its environment
74
Q

what are the 3 ways in which natural selection usually works?

A
  • stabilizing: central phenotype selected over the extremes
  • directional: phenotypes in a specific direction are selected
  • disruptive: extreme phenotypes are selectef for/the mean is selected against, typically in patchy habitats
75
Q

what do “higher” flowers do?

A

flower earlier (elevation)

76
Q

selection is determined by __?

A

the environment

77
Q

describe the beak size/disruptive selection case study

A
  • beak size
  • small beaks eat small seeds
  • big beaks eat big seeds
  • therefore, selection against the mean means less competition
  • intermediate beaks compete with both big and small
  • results in disruptive selection
78
Q

Can natural selection lead to perfection? explain why or why not

A
  • no
  • organisms are locked into historical constraints, and the possible variations on a trait are limited by pre existing forms
  • evolution is about trade offs
79
Q

what is the 3 step pathway of evolution?

A
  • heritable variation
  • selection
  • evolution occurs if there is a change in allele frequency over time
80
Q

what are the 3 different species concepts? what are each of their advantages, disadvantages, and criterion?

A

Morphological
* they look the same
* anatomical differences
* A: widely applicable
* D: vulrebule to convergent evolution

Biological
* most common species concept
* they can breed
* A: based on evolutionary independence
* D: not applicable to asexual species and fossils, must interbreed, and produce viable and fertile offspring

Phylogenetic
* shared ancestory
* A: widely applicable, and testable
* D: few phylogenies availble (what defines distinct species?)

81
Q

What are RIMs (reproductive isolating mechanisms)?

A
  • prevent gene flow between species
  • part of biological species concept
  • can be pre or post zygotic
  • organisms that do not reproduce sexually can only be based on morphological and biochemical characteristics (based on this definiton)
  • have the phases of speciation:

-be genetically seperated (doesn’t always need to happen, sympatry), diverge (due to selective pressure), RIM (can no longer interbreed in nature)

82
Q

what are pre zygotic isolating mechanisms?

A
  • habitat isolation (ex. road across wetland)
  • behavioural isiolation (ex. different mating called, courtship behaviours)
  • temporal isolation (call more in the morning, in day, or in night)
  • mechanical isolation (species won’t cross pollinate)
  • gametic isolation (the gametes cannot fertilize, incompatible)
  • pre zygotic RIM leads to rapid speciation
83
Q

what is post zygotic isolation mechanisms?

A
  • reduced hybrid viability
  • reduced hybrid fertility (ex mules)
  • when the first generation might be viable, while the second generation would not be
  • this is slow, and the baby has reduced viability
84
Q

what is speciation?

A
  • process of evoltuion of two or more distinct species from a single ancestor
  • genetic exchange stops, new lineages go their independent evolutionary ways
  • can occur via genetic isolation: when there is limited gene flow
  • genetic divergence: a result of mutations, natural selection, and genetic drift
  • can be divided into allopatric (diff land) and sympatric (same land)
85
Q

what is allopatric speciation? describe.

A
  • diff land
  • consequence of geographical isolation
  • small subpopulation migrates or becomes isolation, and then genetic drift
  • seperated into dispersal and vicariance
  • dispersal: individuals move to a new location
  • vicariance: the habitat is physically split
  • first step is physical, then you diverge
86
Q

what is the snapping turtle vicariance case study?

A
  • habitat was split
  • shrimp were isolated by panama
  • no gene flow and the populations diverged
  • when together, the the two species fight and not mate (post zygotic RIM)
  • and also an allopatric example
87
Q

what is sympatric speciation?

A
  • consequence of reproductive isiolation inside population range
  • can result from hybridization (allopolyoidy)
  • divergence can also occur when a mutation results in genetic incompatibility

ex. apple maggot fly (rhagoletis)
* hawthorn fruit has slow maturation
* applies: introduce species and mature faster (Ready to eat earlier)
* some switches to apple
* some maggot flies now prefered apples and rapid development
* became temporally (over time) diverged into 2 species (hawthorne maggot and apple maggot)

88
Q

what are hybrid zones and ectonones?

A
  • hybrid zones that can have divergence, with some crossing over
  • hybrid zone called a cline

Clines can be:
* stable selection: for hybrid in cline (some crossing over to create a cline)
* reinforcement of speciation: poor viability of hybrid (seperated- not rly a cline there)
* homogenization: hybrid kinda blends in with the rest (larger)

89
Q

describe the case study in Lake Malawi, and it’s connection to sympatric selection and the cline

A
  • water clarity declining brought them together
  • murky waters means less picky sex (common that there would now be more hybrids)
  • the cline kind of dissapeared, and it grew till it almost overtook
90
Q

what is polyploidy?

A
  • leads to rapid pre zygotic RIM
  • a polyploid individual is produced from one species when a mutation results in the doubling of chromosome number
  • can be autopolyploidy and allopolyploidy
91
Q

What are autopolyploidy and allopolyploidy? explain.

A

Autopolyploidy
* individuals (plants) with more than 2 sets of chromosomes

Allopolyploidy
* the mating of 2 different diploid species resulting in an individual with polyploidy karotypes that might be able to self fertilize (an example of homogenization)

92
Q

what is phylogenetics?

A
  • the study of the evolutionary relatedness among various groups of organisms
  • phylogeny is the evolutionary history of a group of organisms shown in a diagram
93
Q

what are phylogenetic trees?

A
  • graphically reperset hypothesis’s about evolutionary history
  • oldest abd most inclusive taxon at the bottom/trunk
  • most recent taxa at the smaller branching spots
  • nodes: where groups split
  • branches: where evolution occurs
  • tipds: endpoint taxons
  • polytomy: a point where more than two branches diverge (unknown which one happened first)
  • non static (prone to change)
94
Q

what is the difference between monophyletic, paraphyletic, and polyphyletic?

A
  • monophyletic: includes an ancestor and all of its desendencts (called clades or taxa)
  • paraphyletic: include common ancestor but not all descendants (more common)
  • polyphyletic tree: distantly related groups
95
Q

what are homologous structures?

A

share a common ancestor, will contain more genetic similarities, and share a similar embryonic development

96
Q

what are analagous structures?

A
  • similar structures that DO NOT share a common ancestor (ex wings of insects vs birds)
  • result from convergent evolution
  • misleading when building trees
  • can be resolved using homoplasies (fossil records or genetic similarity)
97
Q

what is synapomorphy?

A
  • trait we can use to build a monophyletic tree
  • a shared, derived character (homologous) that provides evidence of the relationship between two taxa
  • cladistic analysis is based on this
  • characteristics of the common ancestor are called basal characters/symplesiomorphy
    *
98
Q

what is autapomorphy?

A

trait that is unique within a group

99
Q

how can you determine which trait is derived or ancesteral?

A
  • use an outgroup
  • if trait is present in outgroup + all of ingroup= ancestral
  • present in outgroup + some in ingroup= ancestral
  • only present in some of ingroup= derived

BIOL 103 Module 1 (8 decks)

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