microevolution/population based evoltuon- pablo and hardy Flashcards
what is population genetics?
study of evolution from a gentic point of view.
modelling of changes in the frequencies of genes and alleles in populations over space and time
what does H-W assume? A large population B new mutation occur C migration D small popualation E assortive mating (more frequent/choice of partner)
OPTION A
assumes RANDOM mating, no mutation, migration and large popualation
what is H-W principle
allelic and genotype frequencies remain constany form generation to genration
> in ABSCENCE of other evolutonary factors
linkage disequilibrium is measured as a
A deviation from mean allele frequency in each locus
B correlation between alleles in same locus
C correlation between allele frequency in different loci
D deviation from mean allele frequency in 2 population
E deviation from mean allele frequency in each locus in 2 populations
OPTION C
is it correlation!!
> this is recombination mapping , how close are genes to each other
> also genes far apart can still be correlated to each other due to their linked function
articificial selection resilts in
some alleles increase in FITNESS under artificial selection
> e.g. farmers do this to get higher reproductive yield
> insecticide resistance
why is H-W calculation helpful for genotype frequencies
TT and Tt are phenotypically INDISTINGUISHABLE
in H-W what does p² mean?
individuals who are homozygous dominant!
sometimes new species branch off from an ancestor and live side by side for some time. this is A convergence B cladogenesis C anagenesis D monophyly E polyphyly
cladogenesis
> this is splitting and branching of lineages``
what is antagonisitc pleitropy of aging?
gene causes negative change in fitness followed by a negative change in fitness later in life
gene causes negative change in fitness, another gene causes negative change in fitness later in life
gene causes postivie change in fitness, another gene causes negative change in fitness later in life
gene causes negative change in fitness followed by a postive change in fitness later in life
gene causes postive change in fitness, follwed by a
negative change in fitness later in life
OPTION E - key work antagonistic (so oppostie effec)
postive –> negative by one gene
eg. mles testosterone increase fitness -> protstae
female prolactin to help offspring -> oestoporosis
adaptive phenotypic plasticity characterised by
A each phenotype optimal in different set of enviroment
B one phenotype has greatest fitness regardleess of environement
C various phenotypes are suboptimal
D same phenotype occurs in different environments having same fitness
OPTION A
E.G pale skin optimasl for Vitamin D absorption but dark skin protects againt UV
H-W and linkage disequilibrium commonly used to
characterise epistatic effects between loci
characterise distribtuion of recomination along genome
detect new mutatiosn in a population
detect presence of popuation structure
identify antagonistic pleisiotropy
OPTION D
what can be a barrier to evolution
insufficient genetic variation in gene pool
no selection pressure occuring in population
what is linkage equilibrium
random association between loci - not correlated
what is NEutral selction?
genes whose FREQUENCY are not influenced by natural selection
> often clsoe to gene loci with adaptive function so get ingerited but does NOT affect individual survival
continuous traits are characterised by A only a few genes involved in the trait B no intermediate phenotype exists C a range of intermediates D each allele contributes to a proportion of phenotype
OPTION C
e.g bristle number in fruitfly
> often environment plays a role
> discontinous is fur colour/ lobed ears
