Week 2 Flashcards
what is altered when you change nucleotides
the codon message leading to phenotypic changes
how can a nucleotide change alter heritable phenotype
if the nucleotides are changed in reproductive cells (somatic cells dont matter for heritability)
what kind of substitution happens when a codon is changed
replacement substitution
where was a replacement substitution first noted
in sickle cell anemia (val for glu)
what are two casual ways for nucleotide changes to occur
replication errors, damaged sites
what are some ways for a nucleotide to be damaged
chemical mutagens and radiation
what are the types of changes happening when a nucleotide changes a codon
transition or transversion
what nucleotides are changed in transition
purine for purine or pyrimidine for pyrimidine (AG or TC)
what nucleotides are changed in transversion
purine for pyrimidine (ACT or GCT)
what type of nucleotide change is more common
transition is more common than transversion
why is transversion less common than transition
transversion is easier to detect in proofreading ebcause it causes a conformational change to the DNA
which group has higher point mutation rates
sexually reproducing organisms have higher point mutation rates
the number of new alleles per individual should match the ____
mutation rate
what is the human mutation rate
1.6 per person (0.8 for sperm + 0.8 for egg)
machinery of DNA replication and repair are encoded by what
all are gene encoded proteins
what are the impacts of mutation to a species
mutations can be detrimental, but mutations are the source of individual variation
why can slight allelic variation help a population
can help population overcome change in environment so they can thrive
if you have a high mutation rate, what is your survival rate
low
how do new genes evolve
genes take on new functions and are evolved
how are new genes formed
gene duplication and unequal crossover
how does unequal crossover of genes work
loss of genes for one chromosome and gaining for the other chromosome (chromosomal alteration)
what is a chromosomal alteration
change in the morphology of chromosomes
what are some consequences of chromosomal alteration
affect gene order and organization, produces duplication and deletions, inversions, polyploidy
what is a chromosomal inversion
break occurs in the chromosome and it flips and reanneals (chromosome attachment can get mixed up)
what is the nickname for genes that have been inverted
supergenes
what is polyploidy
change in number of chromosomes per set
what is polyploidy most common in
plants not animals ( thought it can happen in animals)
what are some animal examples of polyploidy
salamanders, frogs
when is viability in polyploidy low
when polyploid is crossed with normal ploidy
what is a consequence of polyploidy
can cause reproductive isolation
how can you assess genetic diversity
direct measurement of allelic and genotype frequency
what is a direct method for measuring geneti diversity
gel electrophoresis
what does genetic diversity allow for
evolution allows a change in allelic frequency over time
what percent of loci are polymorphic in a population
33-50%
what percent of loci in an individual are heterozygous
4-15%
is allelic variance more neutralist or selectrionist
neutralist
who had a big impact on Darwin as far as natural selection
Thomas Malthus
when was there interest in population dynamics
late 18th century, early 19th
what did malthus hypothesize
populations cannot maintain exponential growth indefinitely due to insufficient resources (geometric increase)
what are the three ideals made by Malthus
geometric increase, resource limitation, intrinsic regulatory mechanisms on population growth and size
the power of population is ___ than the power of earth to produce subsistence for man
greater
subsistence increases in what kind of manner
arithmetical
populations are held within resource limits by what
death rate an birth rate
what scientist came up with the same idea as Darwin on natural selection
Ernst Mayr
what did Mayr contribute to the idea of evolution
multigenerational perspecitive, genetic diversity, importance of environmental interactions
what is differential survival
survival based on different characteristics
what is something darwin underestimated in his evolution theory
the speed at which evolution occurs
what is intraspecific
within a population
what is interspecific
population interacting with environment or other populations
what is a population
group of individduals of the same species that interacts with one another in a given area
what are the three important characteristics for a population
number of individuals, density, biomass, age distribution, growth rate, distribution, genetic makeup
how do two populations interact with each other
competition, predatory prey interactions, symbiosis
what is natality
all reproductive means (asexual vs sexual)
what factors cause change in abundance
loss and gain
what is exponential growth
continuous population growth in an unlimited environment (assumes a perfect or unlimited environment)
what is the equation for exponential growth
dN/dt=rmaxN
how do you calculate the size of an exponentially growing population at any point in time
Nt=Noermaxt
how do you calculate the standing number in a population at any point in time
Nt=BT+IT-DT-ET
how do you calculate the number expected at a future time interval
deltaN=B+I-D-E
organisms that reproduce fast have a fast ___
genetic turnover
what is heroparous
reproduce multiple times in lifetime
what is semelparous
reproduce once then die
what can you have discrete population growth
non-overlapping genetations
what is the name of the figure for discrete population growth
stair stepping cycle
what is logistic population growth
limits in resources cause limits in population size (intraspecific factors)
what is the shape of the logistic population growth graph
sigmoid shaped
what factor is dealt with in logistic population growth
fudge factor
what is the logistic population growth equation
dN/dt=rmaxN((K-N)/K)
what is the key point of the logistic population growth equation
allows for changes in r
what is k
carrying capacity
what are the ideals of robert may
stoichastity between genetations, not everything has same reproducive output, not everything same same lifespan
what did PF Verhulst do
limitations on population growth, fixed resources, logistic growth equation
what did pearl study
extended verhulsts work in population genetics
what does the k value represent
stable number of individuals that can exist in an environment (carrying capacity)
birth and death rates are not always directly related with ___
population density
when will you have the best r value
moderate density
what are the consequences of interspecific interactions
mutualism, partism/predation, interspecific competition
what growth model does intraspecific competition follow
logistic growth model
when does competition between species occur
when there is a sharing of a resource that limits growth, survival, or reproduction of each species
what are examples of resources
food, water, light, space
who did competitive exclusion experiments
Gause
what was gause’s study on
3 species of paramecium, populations stable K when grown alone, when paired some species went extinct
why in gause’s experiment was p. aurelia more successful than p. caudatum
p. aurelia has more efficient feeding
