An ancestor, also known as a forefather, fore-elder or a forebear, is a
parent
A parent is a caregiver of the offspring in their own species. In humans, a parent is the caretaker of a child (where "child" refers to offspring, not necessarily age). A ''biological parent'' is a person whose gamete resulted in a child, a male t ...
or (
recursively
Recursion (adjective: ''recursive'') occurs when a thing is defined in terms of itself or of its type. Recursion is used in a variety of disciplines ranging from linguistics to logic. The most common application of recursion is in mathematics ...
) the parent of an antecedent (i.e., a
grandparent,
great-grandparent
Grandparents, individually known as grandmother and grandfather, are the parents of a person's father or mother – paternal or maternal. Every sexually-reproducing living organism who is not a genetic chimera has a maximum of four genetic gra ...
, great-great-grandparent and so forth). ''Ancestor'' is "any person from whom one is descended. In law, the person from whom an estate has been inherited."
Two individuals have a
genetic relationship if one is the ancestor of the other or if they share a common ancestor. In
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
ary theory, species which share an evolutionary ancestor are said to be of
common descent. However, this concept of ancestry does not apply to some
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
and other organisms capable of
horizontal gene transfer
Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between unicellular and/or multicellular organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). H ...
. Some research suggests that the average person has twice as many female ancestors as male ancestors. This might have been due to the past prevalence of polygynous relations and female
hypergamy
Hypergamy (colloquially referred to as "marrying up") is a term used in social science for the act or practice of a person marrying a spouse of higher caste or social status than themselves.
The antonym "hypogamy" refers to the inverse: marryin ...
.
Assuming that all of an individual's ancestors are otherwise unrelated to each other, that individual has 2
''n'' ancestors in the ''n''th generation before her/him and a total of 2
''g''+1 − 2 ancestors in the ''g'' generations before him/her. In practice, however, it is clear that most ancestors of humans (and any other species) are multiply related (see
pedigree collapse
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 c ...
). Consider ''n'' = 40: the human species is more than 40 generations old, yet the number 2
40, approximately 10
12 or one trillion, dwarfs the
number of humans who have ever lived
This article lists current estimates of the world population in history. In summary, estimates for the progression of world population since the Late Middle Ages are in the following ranges:
Estimates for pre-modern times are necessarily fraugh ...
.
Some cultures confer reverence to ancestors, both living and dead; in contrast, some more youth-oriented cultural contexts display less veneration of elders. In other cultural contexts, some people seek
providence from their deceased ancestors; this practice is sometimes known as ''
ancestor worship
The veneration of the dead, including one's ancestors, is based on love and respect for the deceased. In some cultures, it is related to beliefs that the dead have a continued existence, and may possess the ability to influence the fortune of t ...
'' or, more accurately, ''
ancestor veneration''.
See also
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Archaic humans
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Collateral descendant
A lineal descendant, in legal usage, is a blood relative in the direct line of descent – the children, grandchildren, great-grandchildren, etc. of a person. In a legal procedure sense, lineal descent refers to the acquisition of estate by i ...
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Consanguinity
Consanguinity ("blood relation", from Latin '' consanguinitas'') is the characteristic of having a kinship with another person (being descended from a common ancestor).
Many jurisdictions have laws prohibiting people who are related by blood fr ...
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DNA
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Lysosomal DNA
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Mitochondrial DNA
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Ethnic group
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Family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
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Genealogy
Genealogy () is the study of families, family history, and the tracing of their lineages. Genealogists use oral interviews, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kin ...
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Genetic genealogy
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Kinship
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Lineage (anthropology)
A lineage is a unilineal descent group that can demonstrate their common descent from a known apical ancestor. Unilineal lineages can be matrilineal or patrilineal, depending on whether they are traced through mothers or fathers, respectively. ...
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Lineal descendant
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Most recent common ancestor
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...
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Progenitor
Citations
External links
United States Census Bureau
{{Authority control
Kinship and descent