Distinct groups of repetitive families preserved in mammals correspond to different periods of regulatory innovations in vertebrates

Background Mammalian genomes are repositories of repetitive DNA sequences derived from transposable elements (TEs). Typically, TEs generate multiple, mostly inactive copies of themselves, commonly known as repetitive families or families of repeats. Recently, we proposed that families of TEs originate in small populations by genetic drift and that the origin of small subpopulations from larger populations can be fueled by biological innovations.