A genetic lineage, also known as genetic pedigree, is a series of mutations which connect an ancestral genetic type (allele, haplotype, or haplogroup) to derivative type. In cases where the genetic tree is very bushy the order of mutations in the lineage is mostly known, examples are the order of mutations between E1b1b and E1b1b1a1a for the human Y-chromosomesal L0 or L1 nodes.