lec 29- coevolution Flashcards
what are the 7 different interspecific interactions species can have on one another and what are their effects?
Species A Species B
competition - -
Consumption + -
(herbivory)
(parasitism)
(predation)
Mutualism + +
Commensalism + 0
what are some example of mutualism?
mycorrhizal fungi: converts nitrate into nitrogen for plants and plants give carbon and other nutrients back to fungi
cleaners: eat parasites on animals, while the other gains relief and comfort from lost parasites
what is an example of commensalism?
scavengers: remora attaches to larger fish and eats prey killed by larger fish, doesn’t effect large fish at all
what are example of negative/positive relationships?
predator and prey: one benefits from food while other dies
host and parasite: live in a host and eats off of them, while host falls I’ll and may die
herbivore and plants: herbivore gains food, while plant dies
consumption is heterotrophy, what is heterotrophy?
one organism consumes another for energy and nutrients
what is parasitism?
small organism feeds on larger host and can be slightly damaging or lethal
how was the plague of rabbits in 1859 Australia controlled?
by introducing a parasitic virus that caused myxomatosis in rabbits resulting in their death in 3-4 weeks
what are the 6 parasite/host trade offs?
- ability of parasite to damage or kill host is called virulence
- rapid mutation in virus and bacteria causes several different strains to be in one host, causing competition
- virulence involves competition between strains for rapid reproduction or transmission to new host
- competition initially favors high virulence strains with rapid reproduction
- but high virulence causes rapid death of host, which means the most virulence strains not passed down to new hosts
- transmission to new hosts would be favoured by less virulent strains and a balance develops regarding optimal virulence
what is an example of decelerating arms races?
Australian rabbits and myxoma virus: initially high virulence caused quick death in rabbits so was not selected for, later low virulence didn’t cause death and many rabbits survived
what is the example of coevolutionary arms race in newts?
rough skinned newt warns snakes that is poisonous with its colours (TTX toxin), but some Garter snakes eat it due to immunity while others die
how do some garter snakes live from eating the Tetrodotoxin (TTX) in newts?
because TTX blocks sodium channels in muscles (paralysis) but in garter snakes that can eat them, the sodium channels are mutated to have more resistance
what is the strong paralytic poison found in pufferfish called?
FUGU
what is an example of an arms race between one predators and many other species?
-egg parasites like the cuckoos which lay eggs in many different birds, causing multiple species to be in the arms race
-lions predating on multiple prey
why do cuckoos lay eggs in other nests and how do they prevent their removal?
-they lay eggs in other nests because it saves them energy from not having to raise offspring and they can look for more hosts
-egg mimicry reduces likelihood of removal from nest
how do other birds defend against cuckoo eggs?
-push foreign egg out
-abandon parasitised nest and start another one
what is batesian mimicry and give an example?
-a harmless or palatable mimic resembles a poisonous or distasteful model species (commensalism)
-many harmless butterflies mimic toxic butterflies
-syrphid fly mimics wasp
-nonvenomous snakes mimic venomous snakes
how do edible mimics gain an advantage?
-by mimicing the colors of toxic species, as long as they are rare compared to toxic models
can an arms race to look different occur between mimics and host?
yes
what is mullerian mimicry?
when two or more toxic models mimic each other and are dangerous (mutualism)
e.g. (paper wasp, bumblebee, honey bee, can all sting)
how are many different species of butterflies in the genus heliconius (black red and yellow) different from one another with their mullerian mimicry?
their red colors are slightly different caused by different expressions of the gene optix
how has optix been passed from one species of heliconius to another?
through hybridization (introgression) causing similar patterns
when did coevolution of insects and flowering plants originate?
began in the late mesozoic, with major diversification in the early Cenozoic, especially the Eocene period
is beetle diversity linked to coevolution with plants?
yes, they are herbivores on flowering plants
does coevolution cause diversity and new adaptations?
yes, plants develop chemicals to get rid of insect herbivores and insects develop defenses, showcasing diversity
what was Darwins coevolution prediction about the Madagascar Orchid Angraceum?
that a pollinator with a long tongue coevolved, was found 41 years later as the long-tongued hawk moth
