If this newly found concept applies to fish it could account for much of the variation we see not only from place to place but also within one pond or population.
They have found that each of us is more different genetically than we previously believed. Instead of being 99.9 per cent identical, it may turn out to be more like 99 per cent identical - enough of a difference to explain many variations in human traits. Instead of having just two copies of every gene - one from each parent - we have some genes that are multiplied several times. Furthermore these "multiple copy numbers" differ from one person to another, which could explain human physical and even mental variation.
Until now it was believed the variation between people was due largely to differences in the sequences of the individual " letters" of the genome. It now appears much of the variation is explained instead by people having multiple copies of some key genes that make up the human genome. http://news.independent.co.uk/world/science_technology/article2007490.ece