Exam 4- Adaptations and Animal Behavior

signal

information one individual (the signaler) produces that modifies the behavior of the other individuals (the audience)

to understand why producing a signal would proliferate through natural selection we need to know 2 things:

1. signaler; how does changing the behavior of the audience promote the reproduction of the signaler?

2. audience: how does responding to the signal promote the reproduction of the audience?

the signaler and audience can share two types of reproductive interest:

common reprorudctive interest ( baboons) and conflict of reproductive interest (peacock)

how do females beenefit from paying attention to sexual ornaments?

they may be advertisements of valuable qualities.

advertisements

variation in a phenotype is linked/correlated to the variation of an underlying, unobservable characteristic

• audience should attend to signals like sexual ornaments, those signals advertise valuable, unobservable qualities.

There are incentives for advertisers to lie to audiences, wouldnt deceptive individuals outreproduce honest advertisers on averagee? end result:

1. the preference would stop conferring an advantage

2. the advertisement would then disappear

Since signals do exist, one of two things must be true:

1. the signals are not advertisements

2. the signals are advertisements but something enforces their honesty.

costly signals (handicapping theory)

an advetisement will be honest if the phenotype is costly in terms of the quality it is advertising

ex. stotting

runaway sexual selection

males with preferred traits have enhanced access to females with the preferences AND equal access to females with out the preference. Thus, they have high RS and the preferred trait spreads through the population

why does the female preference evolve?

females with the preference have more attractive sons than do females without the preference, the preference has a reproductive advantage over not having it so selection will further favor the evolution of the preference which would enhance selection for the preference