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Cousins
Most generally, in the lineal kinship system used in the English-speaking world, a cousin is a type of familial relationship in which two relatives are two or more familial generations away from their most recent common ancestor. Commonly, "cousin" refers to a first cousin – a relative of the same generation whose most recent common ancestor with the subject is a grandparent. Degrees and removals are separate measures used to more precisely describe the relationship between cousins. ''Degree'' measures the separation, in generations, from the most recent common ancestor(s) to a parent of one of the cousins (whichever is closest), while ''removal'' measures the difference in generations between the cousins themselves, relative to their most recent common ancestor(s). To illustrate usage, a second cousin is a cousin with a ''degree'' of two; there are three (not two) generations from the common ancestor(s). When the degree is not specified, first cousin is assumed. A cousi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cousin-german
Most generally, in the lineal kinship system used in the English-speaking world, a cousin is a type of Kinship, familial relationship in which two relatives are two or more familial generations away from their most recent common ancestor. Commonly, "cousin" refers to a first cousin – a Kinship, relative of the same generation whose most recent common ancestor with the subject is a grandparent. Degrees and removals are separate measures used to more precisely describe the relationship between cousins. ''Degree'' measures the separation, in generations, from the most recent common ancestor(s) to a parent of one of the cousins (whichever is closest), while ''removal'' measures the difference in generations between the cousins themselves, relative to their most recent common ancestor(s). To illustrate usage, a second cousin is a cousin with a ''degree'' of two; there are three (not two) generations from the common ancestor(s). When the degree is not specified, first cousin is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lineal Kinship
Eskimo kinship or Inuit kinship is a category of kinship used to define family organization in anthropology. Identified by Lewis Henry Morgan in his 1871 work ''Systems of Consanguinity and Affinity of the Human Family'', the Eskimo system was one of six major kinship systems (Eskimo, Hawaiian, Iroquois, Crow, Omaha, and Sudanese). The system of English-language kinship terms falls into the Eskimo type. Joint family The joint family system places no distinction between patrilineal and matrilineal relatives; instead, it focuses on differences in kinship distance (the closer the relative is, the more distinctions are made). The system emphasizes the nuclear family, identifying directly only the mother, father, brother, and sister. All other relatives are grouped together into categories. It uses both classificatory and descriptive terms, differentiating between gender, generation, lineal relatives (relatives in the direct line of descent), and collateral relatives (blood re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arranged Marriage
Arranged marriage is a type of marital union where the bride and groom are primarily selected by individuals other than the couple themselves, particularly by family members such as the parents. In some cultures a professional matchmaker may be used to find a spouse for a young person. Arranged marriages have historically been prominent in many cultures. The practice remains common in many regions, notably South Asia, the Middle East, North Africa, and the Caucasus. In many other parts of the world, the practice has declined substantially during the 19th and 20th centuries. Forced marriages, practiced in some families, are condemned by the United Nations. The specific sub-category of forced child marriage is especially condemned. In other cultures, people mostly choose their own partner. History Arranged marriages were very common throughout the world until the 18th century. Typically, marriages were arranged by parents, grandparents or other close relatives and trusted friends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel And Cross Cousins
In discussing consanguineal kinship in anthropology, a parallel cousin or ortho-cousin is a cousin from a parent's same-sex sibling, while a cross-cousin is from a parent's opposite-sex sibling. Thus, a parallel cousin is the child of the father's brother (paternal uncle's child) or of the mother's sister (maternal aunt's child), while a cross-cousin is the child of the mother's brother (maternal uncle's child) or of the father's sister (paternal aunt's child). Where there are unilineal descent groups in a society (i.e. matrilineal and/or patrilineal), one's parallel cousins on one or both sides will belong to one's own descent group, while cross-cousins will not (assuming descent group exogamy). Role The role of cross-cousins is especially important in some cultures. For example, marriage is promoted between them in the Iroquois system. Parallel cousins are occasionally the subject of promoted marriage, such as the preferential marriage of a male to his father's brother's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The National Academy Of Sciences
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population And Development Review
''Population and Development Review'' is a quarterly peer-reviewed academic journal published by Wiley-Blackwell on behalf of the Population Council. It was established in 1975 and the journal is co-edited by Raya Muttarak and Joshua Wilde. The journal covers population studies, the relationships between population and economic, environmental, and social change, and related thinking on public policy. Content types are original research articles, commentaries, data and perspectives on statistics, archival documents on population issues, book reviews, and official documents from population agencies or related organizations. According to the ''Journal Citation Reports'', the journal has a 2017 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 3.547, ranking it fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitness (biology)
Fitness (often denoted w or ω in population genetics models) is the quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Dar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertility
Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Fertility is addressed when there is a difficulty or an inability to reproduce naturally, which is referred to as infertility. Infertility is widespread, with fertility specialists available all over the world to assist mothers and couples who experience difficulties having a baby. Human fertility depends on factors of nutrition, sexual behaviour, consanguinity, culture, instinct, endocrinology, timing, economics, personality, way of life, and emotions. Fertility differs from fecundity, which is defined as the ''potential'' for reproduction (influenced by gamete production, fertilization and carrying a pregnancy to term). Where a woman or the lack of fertility is infertility while a lack of fecundity would be called sterility. Demograph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inbreeding
Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and other consequences that may arise from expression of deleterious or recessive traits resulting from incestuous sexual relationships and consanguinity. Animals avoid incest only rarely. Inbreeding results in homozygosity, which can increase the chances of offspring being affected by recessive traits. In extreme cases, this usually leads to at least temporarily decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce. An individual who inherits such deleterious traits is colloquially referred to as ''inbred''. The avoidance of expression of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development (a ''de novo'' mutation), or it can be inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA (due to their size). There are well over 6,000 known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recessive Trait
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance such as incomple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 from marrying or having sexual relations with each other. The degree of consanguinity that gives rise to this prohibition varies from place to place. Such rules are also used to determine heirs of an estate according to statutes that govern intestate succession, which also vary from jurisdiction to jurisdiction. In some places and time periods, cousin marriage is allowed or even encouraged; in others, it is taboo, and considered to be incest. The degree of relative consanguinity can be illustrated with a ''consanguinity table'' in which each level of lineal consanguinity ('' generation'' or '' meiosis'') appears as a row, and individuals with a collaterally consanguineous relationship share the same row. The Knot System is a numerical n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
