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An ancestor, also known as a forefather, fore-elder, or a forebear, [1] is a parent or (recursively) the parent of an antecedent (i.e., a grandparent, great-grandparent, 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." [2]
Two individuals have a genetic relationship if one is the ancestor of the other or if they share a common ancestor. In evolutionary 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 and other organisms capable of horizontal gene transfer. 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. [3]
Assuming that all of an individual's ancestors are otherwise unrelated to each other, that individual has 2n ancestors in the nth generation before them and a total of 2g+1 − 2 ancestors in the g generations before them. In practice, however, it is clear that most ancestors of humans (and any other species) are multiply related (see pedigree collapse). Consider n = 40: the human species is more than 40 generations old, yet the number 240, approximately 1012 or one trillion, dwarfs the number of humans who have ever lived.
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, ancestor worship or, more accurately, ancestor veneration is when people seek providence [ further explanation needed ] from their deceased ancestors. [4] [5]
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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 kinship and pedigrees of its members. The results are often displayed in charts or written as narratives. The field of family history is broader than genealogy, and covers not just lineage but also family and community history and biography.
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 the living. Some groups venerate their direct, familial ancestors. Certain religious groups, in particular the Eastern Orthodox Churches, Catholic Church and Anglican Church venerate saints as intercessors with God; the latter also believes in prayer for departed souls in Purgatory. Other religious groups, however, consider veneration of the dead to be idolatry and a sin.
A parent is either the progenitor of a child or, in humans, it can refer to a caregiver or legal guardian, generally called an adoptive parent or step-parent. The gametes of a parent result in a child, a male through the sperm, and a female through the ovum. Parents who are progenitors are first-degree relatives and have 50% genetic meet. A female can also become a parent through surrogacy. Some parents may be adoptive parents, who nurture and raise an offspring, but are not related to the child. Orphans without adoptive parents can be raised by their grandparents or other family members.
In human genetics, the Mitochondrial Eve is the matrilineal most recent common ancestor (MRCA) of all living humans. In other words, she is defined as the most recent woman from whom all living humans descend in an unbroken line purely through their mothers and through the mothers of those mothers, back until all lines converge on one woman.
A family tree, also called a genealogy or a pedigree chart, is a chart representing family relationships in a conventional tree structure. More detailed family trees, used in medicine and social work, are known as genograms.
Consanguinity is the characteristic of having a kinship with a relative who is descended from a common ancestor.
River Out of Eden: A Darwinian View of Life is a 1995 popular science book by Richard Dawkins. The book is about Darwinian evolution and summarizes the topics covered in his earlier books, The Selfish Gene, The Extended Phenotype and The Blind Watchmaker. It is part of the Science Masters series and is Dawkins's shortest book. It is illustrated by Lalla Ward, Dawkins's then-wife. The book's name is derived from Genesis 2:10 relating to the Garden of Eden. The King James Version reads "And a river went out of Eden to water the garden; and from thence it was parted, and became into four heads."
The one-drop rule was a legal principle of racial classification that was prominent in the 20th-century United States. It asserted that any person with even one ancestor of African ancestry is considered black. It is an example of hypodescent, the automatic assignment of children of a mixed union between different socioeconomic or ethnic groups to the group with the lower status, regardless of proportion of ancestry in different groups.
A haplotype is a group of alleles in an organism that are inherited together from a single parent.
The coefficient of relationship is a measure of the degree of consanguinity between two individuals. The term coefficient of relationship was defined by Sewall Wright in 1922, and was derived from his definition of the coefficient of inbreeding of 1921. The measure is most commonly used in genetics and genealogy. A coefficient of inbreeding can be calculated for an individual, and is typically one-half the coefficient of relationship between the parents.
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA), of a set of organisms is the most recent individual from which all the organisms of the set are descended. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms.
Genetic genealogy is the use of genealogical DNA tests, i.e., DNA profiling and DNA testing, in combination with traditional genealogical methods, to infer genetic relationships between individuals. This application of genetics came to be used by family historians in the 21st century, as DNA tests became affordable. The tests have been promoted by amateur groups, such as surname study groups or regional genealogical groups, as well as research projects such as the Genographic Project.
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.
A cousin is a relative that is the child of a parent's sibling; this is more specifically referred to as a first cousin.
An evolutionary lineage is a temporal series of populations, organisms, cells, or genes connected by a continuous line of descent from ancestor to descendant. Lineages are subsets of the evolutionary tree of life. Lineages are often determined by the techniques of molecular systematics.
A genealogical DNA test is a DNA-based genetic test used in genetic genealogy that looks at specific locations of a person's genome in order to find or verify ancestral genealogical relationships, or to estimate the ethnic mixture of an individual. Since different testing companies use different ethnic reference groups and different matching algorithms, ethnicity estimates for an individual vary between tests, sometimes dramatically.
In genetic genealogy, the identical ancestors point (IAP), or all common ancestors (ACA) point, or genetic isopoint, is the most recent point in a given population's past such that each individual alive at that point either has no living descendants, or is the ancestor of every individual alive in the present. This point lies further in the past than the population's most recent common ancestor (MRCA).
DNAPrint Genomics was a genetics company with a wide range of products related to genetic profiling. They were the first company to introduce forensic and consumer genomics products, which were developed immediately upon the publication of the first complete draft of the human genome in the early 2000s. They researched, developed, and marketed the first ever consumer genomics product, based on "Ancestry Informative Markers" which they used to correctly identify the BioGeographical Ancestry (BGA) of a human based on a sample of their DNA. They also researched, developed and marketed the first ever forensic genomics product - DNAWITNESS - which was used to create a physical profile of donors of crime scene DNA. The company reached a peak of roughly $3M/year revenues but ceased operations in February 2009.
The following outline is provided as an overview of and topical guide to evolution:
This glossary of genetics and evolutionary biology is a list of definitions of terms and concepts used in the study of genetics and evolutionary biology, as well as sub-disciplines and related fields, with an emphasis on classical genetics, quantitative genetics, population biology, phylogenetics, speciation, and systematics. It has been designed as a companion to Glossary of cellular and molecular biology, which contains many overlapping and related terms; other related glossaries include Glossary of biology and Glossary of ecology.
