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In genealogy, pedigree collapse describes how reproduction between two individuals who share an ancestor causes the number of distinct ancestors in the family tree of their offspring to be smaller than it could otherwise be. Robert C. Gunderson coined the term; synonyms include implex and the German Ahnenschwund (loosely translated: “loss of lineage”).[1]

How it worksEdit








If a child and parent were to procreate, their offspring would have four grandparents; so, procreation between parents and children would result in less pedigree collapse than procreation between full siblings – although one of the grandparents would also be a parent and therefore introduce no additional genes.



If one considers as a function of time t the number of a given individual's ancestors who were alive at time t, it is likely that for most individuals this function has a maximum at around 1200 AD. It has been suggested that everyone on Earth is at most 50th cousin to everyone else.[5]

See alsoEdit


  1. ^ Gundacker, Felix (2013). "Genealogical Dictionary" (PDF). Archived from the original (PDF) on 2014-04-19.
  2. ^ Dawkins, Richard (1995). "All Africa and her progenies". River Out of Eden. New York: Basic Books. ISBN 978-0-465-06990-3.
  3. ^ Pattison, John E. (2001). "A New Method of Estimating Inbreeding in Large Semi-isolated Populations with Application to Historic Britain". HOMO: Journal of Comparative Human Biology. 52 (2): 117–134. doi:10.1078/0018-442X-00024. PMID 11802564.
  4. ^ Pattison, John E. (July–August 2007). "Estimating Inbreeding in Large Semi-isolated Populations: Effects of Varying Generation Length and of Migration". American Journal of Human Biology. 19 (4): 495–510. doi:10.1002/ajhb.20610. PMID 17546611.
  5. ^ George M.; Adams, Cecil (21 August 1987). "2, 4, 8, 16, ... how can you always have MORE ancestors as you go back in time?". The Straight Dope.


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