Br. Levin et Ct. Bergstrom, Bacteria are different: Observations, interpretations, speculations, and opinions about the mechanisms of adaptive evolution in prokaryotes, P NAS US, 97(13), 2000, pp. 6981-6985
Citations number
64
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
To some extent, the genetic theory of adaptive evolution in bacteria is a s
imple extension of that developed for sexually reproducing eukaryotes. In o
ther, fundamental ways, the process of adaptive evolution in bacteria is qu
antitatively and qualitatively different from that of organisms for which r
ecombination is an integral part of the reproduction process. In this specu
lative and opinionated discussion, we explore these differences. In particu
lar. we consider (i) how, as a consequence of the low rates of recombinatio
n, "ordinary" chromosomal gene evolution in bacteria is different from that
in organisms where recombination is frequent and (ii) the fundamental role
of the horizontal transmission of genes and accessory genetic elements as
sources of variation in bacteria. We conclude with speculations about the e
volution of accessory elements and their role in the adaptive evolution of
bacteria.