Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

In bacteria, DNA sequence mismatches act as a barrier to recombination between distantly related organisms and can potentially promote the cohesion of species. We have performed computer simulations which show that the homology dependence of recombination can cause de novo speciation in a neutrally evolving population once a critical population size has been exceeded. Our model can explain the patterns of divergence and genetic exchange observed in the genus Salmonella, without invoking either natural selection or geographical population subdivision. If this model was validated, based on extensive sequence data, it would imply that the named subspecies of Salmonella enterica correspond to good biological species, making species boundaries objective. However, multilocus sequence typing data, analysed using several conventional tools, provide a misleading impression of relationships within S. enterica subspecies enterica and do not provide the resolution to establish whether new species are presently being formed.

Original publication

DOI

10.1098/rstb.2006.1925

Type

Journal article

Journal

Philosophical transactions of the Royal Society of London. Series B, Biological sciences

Publication Date

11/2006

Volume

361

Pages

2045 - 2053

Addresses

Peter Medawar Building for Pathogen Research, Oxford University, Oxford OX1 3SY, UK. falush@stats.ox.ac.uk

Keywords

Salmonella, Phylogeny, Base Pair Mismatch, Models, Genetic, Computer Simulation, Genetic Speciation