Definition Y-chromosomal Adam

the y-chromosomal recent common ancestor recent common ancestor of y-chromosomes found in living human males.

due definition via living population, identity of mrca, , extension of human y-mrca, time-dependent (it depends on moment in time intended term ). mrca of population may move forward in time archaic lineages within population go extinct: once lineage has died out, irretrievably lost. mechanism can shift title of y-mrca forward in time. such event due total extinction of several basal haplogroups. same holds concepts of matrilineal , patrilineal mrcas: follows definition of y-mrca had @ least 2 sons both have unbroken lineages have survived present day. if lineages of 1 of sons die out, title of y-mrca shifts forward remaining son through patrilineal descendants, until first descendant reached had @ least 2 sons both have living, patrilineal descendants. title of y-mrca not permanently fixed single individual, , y-mrca given population himself have been part of population had own, more remote, y-mrca.

although informal name y-chromosomal adam reference biblical adam, should not misconstrued implying bearer of chromosome human male alive during time. other male contemporaries have descendants alive today, not, definition, through solely patrilineal descent.

by nature of concept of recent common ancestors, these estimates can represent terminus ante quem ( limit before ), until genome of entire population has been examined (in case, genome of living humans).