Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
ORIGINAL ARTICLE doi:10.1111/j.1558-5646.2008.00397.x
 

Summary: ORIGINAL ARTICLE
doi:10.1111/j.1558-5646.2008.00397.x
DEFINED ORDER OF EVOLUTIONARY
ADAPTATIONS: EXPERIMENTAL EVIDENCE
Erez Oxman,1
Uri Alon,1
and Erez Dekel1,2
1Department of Molecular Cell Biology and Department of Physics of Complex Systems, The Weizmann Institute of
Science, Rehovot 76100, Israel
2E-mail: erez.dekel@weizmann.ac.il
Received September 23, 2007
Accepted February 29, 2008
Organisms often adapt to new conditions by means of beneficial mutations that become fixed in the population. Often, full
adaptation requires several different mutations in the same cell, each of which may affect a different aspect of the behavior. Can
one predict order in which these mutations become fixed? To address this, we experimentally studied evolution of Escherichia coli
in a growth medium in which the effects of different adaptations can be easily classified as affecting growth rate or the lag-phase
duration. We find that adaptations are fixed in a defined and reproducible order: first reduction of lag phase, and then an increase
of the exponential growth rate. A population genetics theory explains this order, and suggests growth conditions in which the
order of adaptations is reversed. We experimentally find this order reversal under the predicted conditions. This study supports a
view in which the evolutionary path to adaptation in a new environment can be captured by theory and experiment.

  

Source: Alon, Uri - Departments of Molecular Cell Biology & Physics of Complex Systems, Weizmann Institute of Science

 

Collections: Biology and Medicine