Just based off the press release, and speculating a bit (note: this isn't implied in the article; this is my attempt to link up the long genome / repetitive ele

Just based off the press release, and speculating a bit (note: this isn't implied in the article; this is my attempt to link up the long genome / repetitive elements and number of receptors) Repetitive DNA can allow for increased frequency of DNA recombination; depending on a host of factors (including the relative location of the repetitive elements and the receptor genes, etc) this may facilitate generation of new gene variants for the receptors, increasing the receptor diversity, while preserving / retaining the parent genes. Again, this is very simplistic speculative attempt to join the two dots.