▁surv iv or ship , ▁dispers al ▁and ▁movement ▁patterns , ▁population ▁composition , ▁and ▁gen etic ▁variation ▁within ▁the ▁population . ▁ ▁Population ▁composition ▁The ▁Al lee ▁effect ▁may ▁lead ▁to ▁a ▁higher ▁ext inction ▁probability ▁by ▁causing ▁a ▁crash ▁in ▁the ▁population ▁if ▁the ▁population ▁is ▁subject ▁to ▁un stable ▁fl uct u ations ▁in ▁size . ▁ ▁Because ▁the ▁Al lee ▁effect ▁can ▁arise ▁from ▁vari ability ▁in ▁the ▁numbers ▁of ▁males ▁versus ▁females , ▁sex ▁ratio ▁plays ▁an ▁important ▁role ▁in ▁ext inction ▁probability ▁in ▁the ▁Pers ian ▁fall ow ▁de er ' s ▁population . ▁Having ▁more ▁females ▁than ▁males ▁increases ▁the ▁ch ances ▁of ▁species ▁surv ival ▁because ▁one ▁male ▁can ▁fert il ize ▁multiple ▁females , ▁so ▁fewer ▁males ▁are ▁needed . ▁However , ▁having ▁too ▁many ▁female ▁de er ▁may ▁lead ▁to ▁more ▁inten se ▁pol yg yn ous ▁m ating ▁behav iors . ▁Because ▁males ▁in ▁a ▁pol yg yn ous ▁m ating ▁system ▁are ▁each ▁responsible ▁for ▁fert il izing ▁multiple ▁females , ▁the ▁loss ▁of ▁a ▁single ▁reprodu cing ▁male ▁would ▁reduce ▁the ▁re product ive ▁output ▁of ▁several ▁females ▁in ▁a ▁given ▁bre eding ▁season ; ▁in ▁a ▁compar able ▁mon og am ous ▁system , ▁loss ▁of ▁a ▁single ▁male ▁only ▁affect s ▁the ▁re product ive ▁capacity ▁of ▁one ▁female . ▁For ▁this ▁reason , ▁the ▁population ▁growth ▁rate ▁of ▁a ▁pol yg yn ous ▁system ▁is ▁subject ▁to ▁more ▁fl uct u ations ▁from ▁year ▁to ▁year ▁than