▁intr al ocus ▁sexual ▁conflict ▁ar ises ▁when ▁selection ▁for ▁certain ▁alle les ▁of ▁a ▁gene ▁that ▁are ▁benef icial ▁for ▁one ▁sex ▁causes ▁expression ▁of ▁potentially ▁harm ful ▁tra its ▁by ▁the ▁same ▁gene ▁in ▁the ▁other ▁sex , ▁especially ▁if ▁the ▁gene ▁is ▁located ▁on ▁an ▁aut os om al ▁chrom os ome . ▁ ▁P lei otrop ic ▁gen es ▁act ▁as ▁an ▁arbitr ating ▁force ▁in ▁spe ci ation . ▁William ▁R . ▁R ice ▁and ▁Ellen ▁E . ▁Host ert ▁( 1 9 9 3 ) ▁conclude ▁that ▁the ▁observed ▁pre zy got ic ▁isol ation ▁in ▁their ▁studies ▁is ▁a ▁product ▁of ▁ple iot ropy ' s ▁bal ancing ▁role ▁in ▁indirect ▁selection . ▁By ▁im it ating ▁the ▁tra its ▁of ▁all - in fert ile ▁hy brid ized ▁species , ▁they ▁noticed ▁that ▁the ▁fert il ization ▁of ▁eggs ▁was ▁prevent ed ▁in ▁all ▁eight ▁of ▁their ▁separate ▁studies , ▁a ▁likely ▁effect ▁of ▁ple iot rop ic ▁gen es ▁on ▁spe ci ation . ▁Like wise , ▁ple iot rop ic ▁gene ' s ▁stabil izing ▁selection ▁allows ▁for ▁the ▁alle le ▁frequency ▁to ▁be ▁alter ed . ▁ ▁Studies ▁on ▁fung al ▁evolution ary ▁genom ics ▁have ▁shown ▁ple iot rop ic ▁tra its ▁that ▁simultaneously ▁affect ▁adaptation ▁and ▁re product ive ▁isol ation , ▁converting ▁adapt ations ▁directly ▁to ▁spe ci ation . ▁A ▁particularly ▁telling ▁case ▁of ▁this ▁effect ▁is ▁host ▁specific ity ▁in ▁path ogen ic ▁as com yc etes