Big boys don't recombine.
This is one of the most unnoticed and yet most interesting papers I've read in the last 10 years. Using a large amount of human genetic data, the authors calculated the recombination frequency as a function of position on all 22 somatic human chromosomes. Brief 'splainer: most of us have 22 pairs of somatic chromosomes. One member of each pair comes from our father, one from our mother. However, in the process of making sperm and eggs, our father and mother took each pair of chromosomes they had, and did something called recombination; they spliced the chromosomes together, in one or two places on each chromosome, typically, to produce two new chromosomes, each partly granddad, partly grandma. Then during meiosis they put one of the chromosomes in a single developing sperm or egg. So if grandad's orginal chromosome was blue, and grandma's was red, you inherit one of these two chromosomes from dad (and similarly from mom). X-chromosomes also recombine, but only i...