▁structure ▁of ▁central ▁Asia ▁had ▁three ▁different ▁modes : ▁gene alog ical ▁distance , ▁or ▁the ▁proxim ity ▁of ▁individuals ▁to ▁one ▁another ▁on ▁a ▁graph ▁of ▁kin ship ; ▁gener ational ▁distance , ▁or ▁the ▁rank ▁of ▁generation ▁in ▁relation ▁to ▁a ▁common ▁ancest or ; ▁and ▁birth ▁order , ▁the ▁rank ▁of ▁brothers ▁in ▁relation ▁to ▁each ▁another . ▁The ▁pat ernal ▁descent ▁lines ▁were ▁coll ater ally ▁ranked ▁according ▁to ▁the ▁birth ▁of ▁their ▁found ers , ▁and ▁were ▁thus ▁considered ▁senior ▁and ▁junior ▁to ▁each ▁other . ▁Of ▁the ▁various ▁coll ater al ▁pat ril ines , ▁the ▁senior ▁in ▁order ▁of ▁descent ▁from ▁the ▁found ing ▁ancest or , ▁the ▁line ▁of ▁el dest ▁sons , ▁was ▁the ▁most ▁noble . ▁In ▁the ▁ste ppe , ▁no ▁one ▁had ▁his ▁exact ▁equal ; ▁everyone ▁found ▁his ▁place ▁in ▁a ▁system ▁of ▁coll ater ally ▁ranked ▁lines ▁of ▁descent ▁from ▁a ▁common ▁ancest or . ▁It ▁was ▁according ▁to ▁this ▁id iom ▁of ▁superior ity ▁and ▁inferior ity ▁of ▁line ages ▁derived ▁from ▁birth ▁order ▁that ▁legal ▁claims ▁to ▁superior ▁rank ▁were ▁c ouch ed . ▁Furthermore , ▁at ▁least ▁among ▁Mong ols , ▁the ▁elder ▁son ▁inherited ▁more ▁than ▁the ▁younger ▁son , ▁and ▁this ▁is ▁mand ated ▁by ▁law ▁codes ▁such ▁as ▁the ▁Y assa , ▁created ▁by ▁G eng his ▁Khan . ▁ ▁Among ▁Arab ic ▁pe op les , ▁it ▁is ▁sometimes ▁argued ▁that ▁the ▁expansion ▁of ▁Islam ▁brought ▁an ▁end ▁to ▁the ▁sharp ▁distinction