From molecules to populations: appreciating and estimating recombination rate variation.

Recombination is a central biological process with implications for many areas in the life sciences. Yet we are only beginning to appreciate variation in the recombination rate along the genome and among individuals, populations and species. Spurred by technological advances, we are now able to bring variation in this key biological parameter to centre stage. Here, we review the conceptual implications of recombination rate variation and guide the reader through the assumptions, strengths and weaknesses of genomic inference methods, including population-based, pedigree-based and gamete-based approaches. Appreciation of the differences and commonalities of these approaches is a prerequisite to formulate a unifying and comparative framework for understanding the molecular and evolutionary mechanisms shaping, and being shaped by, recombination.