Reexamining microbial evolution through the lens of horizontal transfer.
Our ability to understand the evolution of microbial organisms revolves around a central and increasingly unsettled question: what is the nature of the mode of inheritance? The extent to which genetic information is passed vertically from parent to daughter or horizontally between distant relatives must guide reconstructions and inferences of evolutionary history, and has direct bearing on any ideas about the mechanisms of selection and diversification. Recent evidence suggests that we may have previously underestimated the contribution of horizontal gene transfer, and the dynamics and extent of this process are only beginning to be understood. The recent flood of complete genome sequences of microorganisms has already presented us with a vast array of data from which to test our hypotheses about the evolution of the entire tree of life, but what remains unclear is how we can make sense of this unwieldy data set. Analyses of this newly available data set should include explicit examinations of the contributions of both types of inheritance.
Planet
Paul J
PJ
Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
D005075:Biological Evolution; D022761:Gene Transfer, Horizontal; D008829:Microbiology; D009876:Operon; D013045:Species Specificity