|
Paragroup
Paragroup is a term used in population genetics to describe lineages within a haplogroup that are not defined by any additional unique markers. In human Y-chromosome DNA haplogroups, paragroups are typically represented by an asterisk (*) placed after the main haplogroup. The term "paragroup" is a portmanteau of the terms paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ... haplogroup indicating that paragroups form paraphyletic subclades. Apart from the mutations that define the parent haplogroup, paragroups may not possess any additional unique markers. Alternatively paragroups may possess unique markers that have not been discovered. If a unique marker is discovered within a paragroup, the specific lineage is given a unique name and is moved out of the paragro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E1b1b
E-M215 or E1b1b, formerly known as E3b, is a major human Y-chromosome DNA haplogroup. E-M215 has two basal branches, E-M35 and E-M281. E-M35 is primarily distributed in North Africa and the Horn of Africa, and occurs at moderate frequencies in the Middle East, Europe, and Southern Africa. E-M281 occurs at a low frequency in Ethiopia. Origins The origins of E-M215 were dated by Cruciani in 2007 to about 22,400 years ago in East Africa. For E-M215 reduced their estimate to 22,400 from 25,600 in , re-calibrating the same data. Ancient DNA According to Lazaridis et al. (2016), Natufian skeletal remains from the ancient Levant predominantly carried the Y-DNA haplogroup E1b1b. Of the five Natufian specimens analyzed for paternal lineages, three belonged to the E1b1b1b2(xE1b1b1b2a, E1b1b1b2b), E1b1(xE1b1a1, E1b1b1b1) and E1b1b1b2(xE1b1b1b2a, E1b1b1b2b) subclades (60%). Haplogroup E1b1b was also found at moderate frequencies among fossils from the ensuing Pre-Pottery Neolithic B cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup E (Y-DNA)
Haplogroup E-M96 is a human Y-chromosome DNA haplogroup. It is one of the two main branches of the older and ancestral haplogroup DE, the other main branch being haplogroup D. The E-M96 clade is divided into two main subclades: the more common E-P147, and the less common E-M75. Origins Underhill (2001) proposed that haplogroup E may have arisen in East Africa. Some authors as Chandrasekar (2007), accept the earlier position of Hammer (1997) that Haplogroup E may have originated in West Asia, given that: * E is a clade of haplogroup DE, with the other major clade, haplogroup D, being exclusively distributed in Asia. * DE is a clade within M168 with the other two major clades, C and F, considered to have already a Eurasian origin. However, several discoveries made since the Hammer articles are thought to make an Asian origin less likely: # Underhill and Kivisild (2007) demonstrated that C and F have a common ancestor meaning that DE has only one sibling which is non-Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup D-M174 (Y-DNA)
Haplogroup D1 or D-M174 is a subclade of haplogroup D-CTS3946. This male haplogroup is found primarily in East Asia, Magar-ethnic Nepal and the Andaman Islands. It is also found regularly with lower frequency in Central Asia, North Asia and Mainland Southeast Asia, and, more rarely, in Europe and West Asia. Origins Haplogroup D-M174 is believed to have originated in Asia some 60,000 years ago. While haplogroup D-M174, along with haplogroup E, contains the distinctive YAP polymorphism—which indicates their closer ancestry than C—no haplogroup D-M174 chromosomes have been found outside of Asia. Haplogroup D1 is also often found in Southern Asia's populations. Several studies (Hammer et al. 2006, Shinoda 2008, Matsumoto 2009) suggested that paternal haplogroup D-M174 originated in Central Asia. A 2017 study by Mondal et al. finds that the Riang people (a Tibeto-Burmese population) and the Andamanese share the same D clade (D1a3, also known as D1a2b) and have their closest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup DE (Y-DNA)
Haplogroup DE is a human Y-chromosome DNA haplogroup. It is defined by the single nucleotide polymorphism (SNP) mutations, or UEPs, M1(YAP), M145(P205), M203, P144, P153, P165, P167, P183. DE is unique because it is distributed in several geographically distinct clusters. An immediate subclade, haplogroup D (also known as D-CTS3946), is mainly found in East Asia, parts of Central Asia, and the Andaman Islands, but also sporadically in West Africa and West Asia. The other immediate subclade, haplogroup E, is common in Africa, and to a lesser extent the Middle East and southern Europe. The most well-known unique event polymorphism (UEP) that defines DE is the Y-chromosome Alu Polymorphism "YAP''"''. The mutation was caused when a strand of DNA, known as Alu, inserted a copy of itself into the Y chromosome. Hence, all Y chromosomes belonging to DE, D, E and their subclades are YAP-positive (YAP+). All Y chromosomes that belong to other haplogroups and subclades are YAP-negative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup R (Y-DNA)
Haplogroup R, or R-M207, is a Y-chromosome DNA haplogroup. It is both numerous and widespread among modern populations. Some descendant subclades have been found since pre-history in Europe, Central Asia and South Asia. Others have long been present, at lower levels, in parts of West Asia and Africa. Some authorities have also suggested, more controversially, that R-M207 has long been present among Native Americans in North America – a theory that has not yet been widely accepted. According to geneticist Spencer Wells, haplogroup K originated in the Middle East or Central Asia. "Given the widespread distribution of K, it probably arose somewhere in the Middle East or Central Asia, perhaps in the region of Iran or Pakistan." However, Karafet et al. (2014) proposed that "rapid diversification ... of K-M526", also known as K2, likely occurred in Southeast Asia (near Indonesia) and later expanded to mainland Asia, although they could not rule out that it might have arisen in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Genetics
Population genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as Adaptation (biology), adaptation, speciation, and population stratification, population structure. Population genetics was a vital ingredient in the emergence of the Modern synthesis (20th century), modern evolutionary synthesis. Its primary founders were Sewall Wright, J. B. S. Haldane and Ronald Fisher, who also laid the foundations for the related discipline of quantitative genetics. Traditionally a highly mathematical discipline, modern population genetics encompasses theoretical, laboratory, and field work. Population genetic models are used both for statistical inference from DNA sequence data and for proof/disproof of concept. What sets population genetics apart from newer, more phenotypic approaches to modelling evolution, such as evolutionary game theory and evolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogroup
A haplotype is a group of alleles in an organism that are inherited together from a single parent, and a haplogroup (haploid from the , ''haploûs'', "onefold, simple" and ) is a group of similar haplotypes that share a common ancestor with a single-nucleotide polymorphism mutation. More specifically, a haplotype is a combination of alleles at different chromosomal regions that are closely linked and tend to be inherited together. As a haplogroup consists of similar haplotypes, it is usually possible to predict a haplogroup from haplotypes. Haplogroups pertain to a single line of descent. As such, membership of a haplogroup, by any individual, relies on a relatively small proportion of the genetic material possessed by that individual. Each haplogroup originates from, and remains part of, a preceding single haplogroup (or paragroup). As such, any related group of haplogroups may be precisely modelled as a nested hierarchy, in which each set (haplogroup) is also a subset of a si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unique-event Polymorphism
In genetic genealogy, a unique-event polymorphism (UEP) is a genetic marker that corresponds to a mutation that is likely to occur so infrequently that it is believed overwhelmingly probable that all the individuals who share the marker, worldwide, will have inherited it from the same common ancestor, and the same single mutation event. Generally, UEP is an allele for which all copies derive from a single mutational event. In genetic genealogy, the mutations considered to be UEPs can be any germline mutation. They are usually single-nucleotide polymorphisms (SNP) – the replacement of one letter by another in the DNA sequence, and the terms UEP and SNP are often loosely used interchangeably. But UEPs may also be large-scale additions, such as the YAP insertion that defines Y-DNA haplogroup DE, inversions or deletions. The discovery and widespread testing of new UEPs has been the key to the increasingly detailed analysis of the patrilineal and matrilineal ancestry of man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Y-chromosome DNA Haplogroup
In human genetics, a human Y-chromosome DNA haplogroup is a haplogroup defined by specific mutations in the non-Genetic recombination, recombining portions of DNA on the male-specific Y chromosome (Y-DNA). Individuals within a haplogroup share similar numbers of short tandem repeats (STRs) and single-nucleotide polymorphisms (SNPs). The Y-chromosome accumulates approximately two mutations per generation, "one mutation in every 30 million base pairs" and Y-DNA haplogroups represent significant branches of the Y-chromosome phylogenetic tree, each characterized by hundreds or even thousands of unique mutations. The Y-chromosomal most recent common ancestor (Y-MRCA), often referred to as Y-chromosomal Adam, is the most recent common ancestor from whom all currently living humans are descended Patrilineality, patrilineally. Y-chromosomal Adam is estimated to have lived around 236,000 years ago in Africa. By examining other population bottlenecks, most Eurasian men trace their descent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterisk
The asterisk ( ), from Late Latin , from Ancient Greek , , "little star", is a Typography, typographical symbol. It is so called because it resembles a conventional image of a star (heraldry), heraldic star. Computer scientists and Mathematician, mathematicians often vocalize it as star (as, for example, in ''the A* search algorithm'' or ''C*-algebra''). An asterisk is usually five- or six-pointed in printing, print and six- or eight-pointed when handwritten, though more complex forms exist. Its most common use is to call out a footnote. It is also often used to censor offensive words. In computer science, the asterisk is commonly used as a wildcard character, or to denote pointer (computer programming), pointers, repetition, or multiplication. History The asterisk was already in use as a symbol in ice age Cave painting, cave paintings. There is also a two-thousand-year-old character used by Aristarchus of Samothrace called the , , which he used when proofreading Homeri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portmanteau
In linguistics, a blend—also known as a blend word, lexical blend, or portmanteau—is a word formed by combining the meanings, and parts of the sounds, of two or more words together.Garner's Modern American Usage p. 644. English examples include '' smog'', coined by blending ''smoke'' and ''fog'', and '''', from ''motor'' ('' motorist'') and ''hotel''. A blend is similar to a [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic grouping (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics, having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia (reptiles), which is paraphyletic with respect to birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
