Relationships and phylogenies Flashcards
clade
entire portion of phylogeny from a single - or COMMON - ancestor
cladogram
evolutionary tree with points of divergence on it
phylogenetic trees
pedigree of lineage
ancestral
shared by a common ancestor
derived
differs from lineage ancestor
any 2 traits from ancestor
homologous
parsimony
simplest is correct (reversal and changes in traits - evolutionarily)
estimating and using phylogenies
predictive epidemiology
compatibility for schistosomes
sister clade or ancestral to Africa
panmictic unit
area that organism lives, breeds and dies within
diseases
large infection network =>
higher virulence of disease
pathogen does not have to keep host alive for as long in order to be passed on
Advantages/disadvantages of being ‘selfers’
eggs few and large high quality offspring low juvenile mortality low reproductive investment late maturation high altitudes/latitudes biologically simple habitats
Advantages/disadvantages of being ‘outcrossers’
eggs many and small low quality offspring higher juvenile mortality high reproductive investment early maturation lower latitudes/altitudes biologically complex habitats
why ‘selfers’ at high latitudes and altitudes?
fewer parasites/pathogens
better to invest resources in suiting environment than defence against pathogens/parasites
general homologous
all species in lineage
e.g. vertebrae
special homologous
few species in lineage
e.g. indeterminate incisors
special homologous traits order…
TIME of separation
Ability to host schistosomes =
homologous
Resistance to schistosomes =
analogous
outgroup
branched off from below base of lineage
schistosome compatibility theory conclusion
snails in Americas and Africa
snails moved from Americas to Africa
glabrata ancester (ancestral biomphalaria)
to B.pfeifferi, B. sudanica and B. alexandrina
Cepaea nemoralis
good to look at for ecological genetics easily defined panmictic unit low vagility highly polymorphic tractable
AKA Grove Snail
Cepaea nemoralis studies
crypsis
thermal selection
Island house mouse
small panmictic unit highly polymorphic moderately-highly vagile tractable good system to study
Isle of May Mice after effect
more aggressive mice of hybrids becoming less aggressive again
huddling behaviour returning
… evolution in action? - better to be in those conditions?
partitioning genetic variation
sexual/asexual
host-parasite - host escapes by evolving resistance
bryozoans (genetics with parasites)
budding, self/outcross
good dispersal
few, widespread clones
fugitive lifestyle (can’t kill them all if spread out)
asexual statoblasts
produced at end of season - vs.sexual overwintering propagules
parapatric species
have adjacent but non-overlapping distributions
