L10 Communication Flashcards
What is cumulative selection?
A series of single step selection, the output of one step leads to the next
What has cumulative selection in female hyenas led to?
Englarged clitoris - the female penis
What is the adaptive significance of the female penis?
May have been due to selection on high levels of male sex hormones in infants to allow for siblicide, or because selection on high levels of male sex hormones that make females larger as adults
What is the female penis used for nowadays?
Evolved as a means of signalling to other hyenas
What requirements must be met for signals to evolve?
Signal must be perceived by other members and be adaptive to survival
What is sensory exploitation?
Biasing effect of exiting perceptual mechanisms on the origins of new communication signals, preferences evolve first, followed by the traits that elicit them, because of female sexual choice
How can sensory exploitation be seen in sword fish and platyfish?
Platy fish has short tail, sword tail has a long one, added long tails to platy fish to see if it affected female mate choice, it did, showed a preference for longer tails
How can sensory exploitation be seen in cuckoos?
Segregation of reed warbler chick begging calls and cuckoo chick reveals that cuckoos beg with the same level of intensity as a whole brood of reed warblers, means they get more food
What is the compromise of signal size?
Takes energy to perform but may be adaptive for the signaller
Give an example of an honest signal in red seer stag
Stags roar during breeding season, strength/duration of roar depends on fitness, means they avoid fighting by announcing themselves to females without competing physically. Wards the weaker males off, no point engaging if going to lose
How do flowers and insects communicate?
Nectar guides, UV parts in the flower that alert insect to presence of nectar.
How have horse chestnut adapted to signal to insects?
Yellow flowers when nectar is present, turn pink when not
What does hip to waist ration symbolise?
is correlated with high reproductive capacity and health
What do you need to know to understand the evolution of communication signals?
The origins of the signal, the changes taking place in signallers ad receivers and the casual processes causing the changes
