Speciation and Introgression between Mimulus nasutus and Mimulus guttatus
PLoS Genet, 10 (6):
e1004410 (Juni 2014)DOI: 10.1371/journal.pgen.1004410
Zusammenfassung
While speciation is often depicted as a simple population split, in many cases it is likely more complex. Recently, whole genome sequencing and computational methods to interpret patterns of genomic variation have facilitated the inference of complex speciation histories. We present and analyze genomic data to infer the speciation history of an ecological and evolutionary model species pair - <italic>Mimulus guttatus</italic>/<italic>M. nasutus</italic>. We infer that <italic>M. nasutus</italic> split from a central Californian <italic>M. guttatus</italic> population approximately 200–500 kya, roughly corresponding to <italic>M. nasutus</italic>’ shift to self-fertilization. We document ongoing gene flow between these species where they co-occur. Finally, we present patterns genomic divergence suggesting that natural selection disfavors introgression of <italic>M. nasutus</italic> ancestry in <italic>M. guttatus</italic>.