Fitness and co evolution Flashcards
What is
Fitness and indication of
AN indinviduals ability to be successful at reporduction and survival
WHat does
Fitness infer
Some organisms in a species can be better at producing surviving offspirng than others. They contribute more to the gene pool of next gen.
Absolute Fitness
The ratio between number of indivduals of particular genotype after and before selection
FREQUENCY OF PARTCULAR GENOTYPE AFTER SELCTION
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FREQUENCY BEFORE SELCETION
ABsolute fitness at more and less than 1
- If AB is 1, frequency of genotype is stabel
- Greater than 1, increase in genotype
- Less than one, a decrease
Relative fitness
No. of surviving offspring per indivudal of particular genotype
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No. of surviving offspring per indivdual of most successful genotype
Co evolution
Two or more species evolve in response to pressures imposed by the other
Symbiosis
Co-evolved intimate relationship betwen en two different species.
Impacts can be (+) (-) or (0)
Mutualism
Both organisms are independent on each other for resources/other services
Both gain, relationship is (+), (+)
Commensalism
Only one species benefits
(+), (0)
Parasitism
Parasite benefits energy and nutrients and host is harmed as a result.
(+/-)
EG parasites and plasmodium/human hosts
Fitness in paraistism relationship
Hosts better able to resists and tolerate parasites have greater fitness
Parasits better able to feed, reporduce and find new hosts = greater fitness
Red Queen hypothesis
In a co evolutionary relatiuonship, the changes in the traits of one species acts as a aselcetion pressure on the other. Meaning species must adapt to avoid extinction
