One of the first studies of UCEs showed that certain human DNA sequences of length 200 nucleotides or greater were entirely conserved (identical nucleic acid sequence) in human, rats, and mice.
Un dos primeiros estudos sobre UCEs mostrou que certas secuencias de ADN humanas dunha lonxitude de 200 nucleótidos ou maiores estaban totalmente conservadas (tiñan idéntica secuencia de nucleótidos) en ratas e ratos.