▁have ▁overlap ▁with ▁segment al ▁dup lication , ▁and ▁those ▁NUM T s ▁were ▁found ▁in ▁only ▁one ▁of ▁the ▁copies ▁while ▁missing ▁from ▁the ▁others , ▁clearly ▁demonstr ating ▁that ▁the ▁NUM T s ▁were ▁inserted ▁subsequent ▁to ▁the ▁dup lication ▁events . ▁De let ion ▁is ▁another ▁NUM T ▁post - insert ional ▁modification ▁method ▁that ▁has ▁not ▁yet ▁been ▁studied ▁in ▁the ▁same ▁amount ▁of ▁detail ▁as ▁an ▁insert ion . ▁Constant ▁er os ion ▁of ▁ph y log en ic ▁signals ▁and ▁high ▁mut ation ▁rate ▁in ▁animal ▁m t D NA ▁make ▁recognition ▁of ▁such ▁modification , ▁especially ▁delet ion , ▁difficult . ▁Stud ying ▁the ▁cases ▁in ▁which ▁the ▁presence – abs ence ▁pattern ▁of ▁NUM T s ▁does ▁not ▁agree ▁with ▁the ▁ph y log en etic ▁tree , ▁should ▁make ▁detection ▁of ▁recent ▁NUM T ▁losses ▁possible ▁by ▁the ▁means ▁of ▁using ▁multiple ▁gen ome ▁align ments ▁with ▁the ▁presence ▁of ▁an ▁out group . ▁B ens ass on ▁and ▁his ▁team ▁members ▁used ▁this ▁method ▁to ▁estimate ▁the ▁oldest ▁inserted ▁NUM T ▁in ▁human , ▁which ▁dated ▁around ▁ 5 8 ▁million ▁years ▁ago . ▁ ▁General ▁characteristics ▁of ▁NUM T ▁ ▁As ▁the ▁number ▁of ▁mit och ond ria ▁and ▁their ▁functional ▁level ▁diff ers ▁across ▁e uk ary otic ▁organ isms , ▁the ▁length , ▁structure , ▁and ▁sequence ▁of ▁NUM T s ▁vary ▁dram atically . ▁Research ers ▁have ▁found ▁that ▁the ▁recent ▁NUM T ▁insert ions ▁are ▁derived ▁from ▁different