handout 4.12.11 - 4/12/11 1. Millions of years ago (mya)...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
4/12/11 1. Millions of years ago (mya) – Refers here to the time since two species shared a common ancestor 2. Rule of functional constraint – Hypothesis that biologically important DNA and protein sequences are under strong selective constraints, and thereby, evolve slowly; conversely, less important sequences are under weak selective constraints, and thereby, are free to evolve rapidly 3. Molecular clock – Hypothesis that DNA and protein sequences fix mutations at a near constant rate; thus, two species will exhibit sequence differences in proportion to how long ago they last shared a common ancestor ------------------------------------------------------------------------------------------------------------------------------- MUTATION AS EVOLUTIONARY FORCE (i.e., driver of allele frequency change) 1. Negligible evolutionary force, mutation rate is simply too slow 2. Nevertheless, critical as ultimate source of all genetic variation Without genetic variation, there can be no change (evolution)
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 06/08/2011 for the course PCB 3063 taught by Professor Marta during the Spring '08 term at University of Florida.

Page1 / 2

handout 4.12.11 - 4/12/11 1. Millions of years ago (mya)...

This preview shows document pages 1 - 2. Sign up to view the full document.

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