Meiosis is the process by which our bodies create sex cells (egg and sperm).  It involves a reshuffling of the genetic deck, so to speak.  One step in meiosis, known as DNA recombination or "crossing over," contributes significantly to the widespread diversity we see in human traits.  A nice description of the process by which egg and sperm are formed can be found at this National Institutes of Health website.

The basic process has been understood for some time, but now researchers at the University of Chicago and in Iceland have revealed new insights into exactly how and where on our chromosomes the genetic reshuffling process occurs.

Original Article