In 2020, the sequencing of ancient dog genomes indicates that dogs share a common ancestry and descended from an ancient, now-extinct wolf population - or closely related wolf populations - which was distinct from the modern wolf lineage. By the close of the last Ice Age (11,700 YBP), five ancestral lineages had diversified from each other and were expressed in dog samples taken from the Neolithic era Levant (7,000 YBP), Mesolithic era Karelia (10,900 YBP), Mesolithic era Baikal (7,000 YBP), ancient America (4,000 YBP), and the New Guinea singing dog (present day).