A primary goal in evolutionary biology is to understand the forces that operate in the genomic sequences and are responsible for the adaptation of different species to different environments. Modeling adaption is tricky and typically relies on one of two approaches. Phylogenetics describes species evolution based on interspecific variation. Differently, population genetics uses intraspecific variation to explain the genetic differences in one or among several closely related populations. Both approaches are helpful as they rely on different time scales. However, with the recent increase in genome sequence data, we are now dealing with evolutionary questions on the realm of speciation and divergence, which require the combination of both approaches.
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