Inson az davrahoi qadim ba monandi va farqiyati volidonu naslho maroq zohir namuda, kushish mekard, ki asosi in muammoro dark namoyad.
Az chi sabab baze alomatho dar hamai naslho zohir meshavand, ammo digar guruhi alomatho va khosiyatho boshand, goh dar naslho paydo shuda, goho zohir nameshavand. Aknun malum gardid, ki genho va khromosomaho barandai alomatho meboshand.
Dar natijai faoliyati ba ham aloqamandii genho va muhiti zist alomathoi organizmho zohir meshavand.