{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

FA2008 - BILD 3 - Lecture 04 (Natural Selection - 03)

FA2008 - BILD 3 - Lecture 04 (Natural Selection - 03) -...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
10/14/08 1 Negative frequency dependent selection example #3 Evolution of sex ratio In many animals, sex ratio = 1:1 Why? Sex ratio = proportion males Imagine population sex ratio = 0.25 (1 male for every 3 females; female-bias ) Assumptions: every female has 4 offspring; every male gets equal share of mates F F F M F F F 4 4 4 4 4 4 Imagine that one couple has 2 sons and 2 daughters (every male still gets equal share mates (3))
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mom & dad F F M M F F F 4 4 4 4 4 F F F = 32 grandchildren 4 4 4 = 24 grandchildren In a female-bias sex ratio, production of males would be favored by selection Eventually, population would become male-biased, not all sons could mate, selection would favor female bias… Selection favors production of the less common sex – negative frequency dependent selection...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online