lec 20- selection in the wild cont. Flashcards
what gene is responsible for the armour on sticklebacks?
Eda
what genotypes do Marine and freshwater stickleback have?
marine = EE or Ee (armoured or intermediately armoured)
freshwater = ee (no armour)
does reduced Eda expression result in reduced armour and spines?
yes
how long does evolutionary transitions in sticklebacks take?
a few decades, (marine high Eda stickelbacks turned into low Eda)
what are the two stickleback variants that showcased rare coevolution?
-benthic low Eda with robust body and large mouths
-limnetic smaller and not robust
if competitive exclusion predicts one of these two should be eliminated, why haven’t they?
because they both feed in different niches
-benthic on larger invertebrates
-limnetic on small crustaceans
how do hybrids between the two morphs of sticklebacks perform in either habitat?
they do bad as bad equipped for both environments
are the limnetic and benthic sticklebacks a sympatric population?
yes, they showcase signs of speciation while being in the same environment
evolutionary change can happen in response to selection if:
-there is variation
-variation is heritable
-resources are reallocated to maximize fitness like from protection to reproduction
what do gall flies do to goldenrod gall plants?
induce plants to produce galls on goldenrod plants to feed their larvae
does the gall size effect the fitness of the gall fly?
yes, because the gall size is responsible for the survival of the fly larva
what determines the gall size?
the flies, they determine different sizes based on selectional pressures in different areas
what happens to large galls in the winter?
large gall predation is more prominent by woodpeckers in the winter, resulting in better survival of smaller galls
what happens to small galls?
parasitic wasps attack the fly larva and lay their eggs only in small galls (opposite selection), resulting in better survival of larger galls
what size of galls are best for fly fitness?
intermediate are favored by sleection
what are other extended phenotypes like galls that are produced by organisms?
webs, nests, termite mounds
are human cities extended phenotypes?
yes, because they are structures that are made that have an influence on fitness
how did humans lead to the artificial selection of samurai ghost crabs?
-fishermen who cot them threw them back thinking they are ghosts of samurais
-led to increased number of them due to more survival
what is pareidolia?
the illusionary manifestation wrought by the human brain’s ability to recognize faces and human forms
what does artificial selection in crop production select for?
more crops, bigger, tastier
does artificial selection reinforce hidden genetic variation?
yes
what mutation in wild grains is beneficial for humans when it comes to harvesting?
mutations that reduce shattering and seed release, resulting in grains being clustered when ripe and clustered seeds that are easier to harvest
for how many years have dog diversity been created?
15,000 years
did the dire wolf live with gray wolves and did they interbreed?
-yes, dire wolves lived with grey wolves in americas and east Asia (125,000-10,000 ya)
-they had a heavier build and were more robust but did not interbreed
do insecticides and herbicides act as strong agents of selection?
yes (high S)
what is the active ingredient in herbicides that attack the plant enzyme EPSPS?
Glyphosate
how are plants more resistant to glyphosate now?
they produce larger quantities of EPSPS, and one grass has a mutation in EPSPS where one amino acid changes, causing more resistance
have flies been becoming more resistant to pesticides?
yes
what has trophy hunting caused in large horned animals?
-large horned animals die, resulting in small horn and smaller sized to live
-also effect breeding as larger individuals with large horns have higher breeding success
what does overfishing do to cod?
reduces age of sexual maturity in survivors
how does reduced age of maturity and smaller bodies of cod affect egg production?
small fish produce less eggs than large, so recovery is slowed
