Some biologists recognise just two types: viability (or survival) selection, which acts to increase an organism's probability of survival, and fecundity (or fertility or reproductive) selection, which acts to increase the rate of reproduction, given survival.
Biologist tan iyyat ardahan fal issin ich-ikilan ɣas: nefran n tudabat n tamudre (meɣ tamudre) tisawadat irrizaɣ n organizm n tamudre d nefran n akarach n aratan (meɣ tudabat n akarach n aratan meɣ araw) isawadan iddikud n aratan ijraw nen tamudre