Biology 3436F/G Lecture 24: 3436F - Lecture 24 - Guest Lecture.docx
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24 Jan 2015
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Guest Lecture
Honest Advertisement
•Redwing blackbirds
oExtend wings and expose the bright colouration
oAdvertise territory
•Direct
oPhysical benefit
•Indirect benefits
oGenes passed to offspring
Indirect Benefits
•Wide variety of perching birds had lower number of parasites
•Birds may advertise their immune system by colouration
•Males that had more red had fewer parasites
•Bauer birds
oBuilds elaborate bauers of twigs
oThe more elaborate the bauer, the fewer parasites
oThe more ultra violet their plumage, the healthier they are
Mate choice hypotheses
•Males presents themselves to the females
•Good genes
oMost valid to explain plumage in birds
oCertain alleles that advantageous that the female mating with that male, the
offspring will inherit these
oAdditive effect, builds on top
•Genetic compatibility
oHow the genes interact
oThe more shared MHC alleles there are, the more immune they are to pathogens
•Fisherian Runaway Selection
oIf female likes a certain trait and this continues to happen
oThe trait may become disadvantageous to survival
oIt is not always good to have this
oTrait selection and preference for the trait start to coevolve
Avian-visual spectrum
•Birds some UV peaks where they are seen like this by each other even though the appear
dull to humans
Plumage Types
•Carotenoids in the cardinal, need to eat these to produce their colour