#7 - Life Histories

#7 - Life Histories - The Evolution of Life Histories A...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 The Evolution of Life Histories A life history consists of the overall set of traits an organism possesses that directly affect the number of successful offspring it produces. – These are sometimes referred to as “decisions”, but they are “decisions” in the evolutionary sense, not “decisions” in the conscious sense – Like any other trait, a life history can evolve, and it does so via selection acting upon the various individual traits that combine to make up the overall life history Life history traits Age/size at first reproduction Reproductive effort Clutch size Egg size Growth rate? Allometric considerations “Higher-level” traits : * Mode of reproduction (egg- laying; live-bearing); * aspects of development; etc. Two key concepts Constraints Trade-offs
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Life history traits Age/size at first reproduction Reproductive effort Clutch size Egg size Growth rate? Allometric considerations “Higher-level” traits : * Mode of reproduction (egg- laying; live-bearing); * aspects of development; etc. An organism’s life history can be thought of as a sequential set of coordinated “decisions” • 1. When is it appropriate to begin reproducing (move from juvenile to adult stage)? Age/size at reproduction • 2. Once mature, how much “ effort ” should be put into reproduction, versus other needs such as acquiring food,
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/24/2008 for the course BIOL 216 taught by Professor Baker during the Spring '08 term at Clark University.

Page1 / 6

#7 - Life Histories - The Evolution of Life Histories A...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online