The nature and scale of recombination rate variation are largely unknown for most species. In humans, pedigree analysis has documented variation at the chromosomal level, and sperm studies have identified specific hotspots in which crossing-over events cluster. To address whether this picture is representative of the genome as a whole, we have developed and validated a method for estimating recombination rates from patterns of genetic variation. From extensive single-nucleotide polymorphism surveys in European and African populations, we find evidence for extreme local rate variation spanning four orders in magnitude, in which 50% of all recombination events take place in less than 10% of the sequence. We demonstrate that recombination hotspots are a ubiquitous feature of the human genome, occurring on average every 200 kilobases or less, but recombination occurs preferentially outside genes.

Original publication




Journal article



Publication Date





581 - 584


African Continental Ancestry Group, Base Composition, Bayes Theorem, Chromosome Mapping, Chromosomes, Human, Pair 19, Chromosomes, Human, Pair 20, Chromosomes, Human, Pair 22, Computational Biology, European Continental Ancestry Group, Female, Genes, Genetic Variation, Genetics, Population, Genome, Human, Humans, Linkage Disequilibrium, Male, Markov Chains, Monte Carlo Method, Pedigree, Polymorphism, Single Nucleotide, Recombination, Genetic, Reproducibility of Results