6. what do we mean by genetic diversity Flashcards
what kinds of genetic variation exists
mutations to DNA persisting
on phylogenetic tree, if there’s one lineage further separated, what does it mean
more genetic diversity
more different
assigning conservation value
for distinct one, too far from evolution
for close one, not much genetic diversity as similar ones nearby
what is the pragmatic approach to phylogenetic
if the lineage is the source of evolutionary change due to distinctive and conservation occurring
what is a better predictor than phylogeny
life history
smaller species with less parental investment
and
highly fecund species
are more…
diverse
2 ways to study genetic diveristy
- genotypic variation through DNA
- phenotypic variation
genotypic variation, what we look at
differences in one or more locus anf see if they affect phenotype
phenotypic variation, what we look at
see if phenotypic differences have genetic basis
what is an example of genetic difference causing phenotypic variation
discrete colour polymorphism
what is polymorphism maintained with
natural selection
sexual selection
what is the common garden experiment using yarrow
controlling environmental effects, the clones of yarrows were different
environment and genetics have an effect on morphology
Does feeding behaviour have a genetic basis, behavioural phenotype
yes, it represents intraspecific genetic diversity
phenology of flowering is under what control
genetic control
what do flower phylogeny trees tell you
closely related genetically flowers have similar flowering dates
why should we conserve genetic diveristy
important source of biological variation
Helps with health and persisitence of populations
needed for evolution
heterozygosity is related to fitness
what does natural selection operate on
GENETIC DIVERSITY
so that there’s adaptations for changing conditions
in disruptive selection
average phenotype is least fit
in stabilizing selection
extreme phenotypes are least fit
in directional selection
on extreme phenootype is super fot
which 2 selections actually reduce genetic diveristy in population
stabilizing and directional
what does natural selection do
reproductive isolation so new species, so genetic diversity
how to calculate heterozygosity
add all the heterozygosity values together, divided by the number of individuals
what is polymorphism
proportion of loci which have more than one allele
how to calculate polymorphism
number of polymorphic loci/ total number of loci in the sample
vertebrates, invertebrates and plants are usually
heterogygous
how does heterozygous affect fitness in mussel
increased length when heterozygosity increase, thus fitness
how does heterozygosity affect developmental stability
chromosomes correlated with wing length variance
heterozygous- more pairs fo chromosomes
have less variance in wing length
more symmetry
more developmental stability and higher fitness
how does heterozygosity affect fecundity of grass
more seeds, more fecund when hetero
numbeer of branches with flowers increase
same relationship with leaf weight as well
relates to fitness
what suggests that genetic diversity and fitness have weaker link
meta analysis
why did meta analysis show weak link between genetic diversity and fitness
loss of heterozygosity had negaetive effects on fitness, that is why worth conserving genetic diversity
some studies had negative correlation
what was another article about weak relationship about genetic diversity and fitness in animals
not zero, but weak link
it is an average across lots of studies, so why are populations so different everywhere
life history traits have higher correlation as compared to physiological and morphological
