Post-insertion modification:The complex pattern of NUMT in comparison with the single mitochondrial piece, the appearance of non-continuous mitochondrial DNA in the nuclear genome, and possibly, different orientation of these fragments are the evidence of post-insertion processes of NUMT within the nuclear genome. The causation of these complex patterns might be the result of multiple NUMT insertions at insertional hotspots. In addition, duplication after insertion contributes to NUMT diversity. NUMTs have no self-replicating mechanism or transposition mechanism; therefore, NUMT duplication is expected to occur in tandem or to involve larger segmental duplication at rates representative of the rest of the genome. Evidence for NUMT duplications that are not in proximity to other NUMTs is present in many genomes and probably happens as part of segmental duplication. However, duplications of recent human-specific NUMTs as part of segmental duplication seem to be rare; in humans, only a few NUMTs are found to have overlap with segmental duplication, and those NUMTs were found in only one of the copies while missing from the others, clearly demonstrating that the NUMTs were inserted subsequent to the duplication events. Deletion is another NUMT post-insertional modification method that has not yet been studied in the same amount of detail as an insertion. Constant erosion of phylogenic signals and high mutation rate in animal mtDNA make recognition of such modification, especially deletion, difficult. Studying the cases in which the presence–absence pattern of NUMTs does not agree with the phylogenetic tree, should make detection of recent NUMT losses possible by the means of using multiple genome alignments with the presence of an outgroup. Bensasson and his team members used this method to estimate the oldest inserted NUMT in human, which dated around 58 million years ago.