In definite variability is a much more common result of changed conditions than definite variability, and has probably played a more important part in the formation of our domestic races.
Aldagarritasun zehazgabea aldagarritasun zehatza baino gehiagotan da baldintzak aldatzearen emaitza, eta etxe-arrazak eratzen zeregin garrantzitsuagoa jokatu bide du.