The Eurasian Heartland: A continental perspective on Y-chromosome diversity. Author Affiliations Contributed by Walter F. Bodmer Abstract The nonrecombining portion of the human Y chromosome has proven to be a valuable tool for the study of population history. The maintenance of extended haplotypes characteristic of particular geographic regions, despite extensive admixture, allows complex demographic events to be deconstructed. Human population genetics uses the distribution of genetic markers in extant human populations to gain an insight into demographic and migrational history. Recently, diversity on the nonrecombining portion of the Y chromosome (NRY) has been applied to the study of human history (5, 6). The ease with which recently described biallelic NRY markers (8) can be typed and assigned to haplotypes promises to reveal many details of human history that were unclear from the analysis of other genetic markers.
Methods Samples. Genotyping. Table 1 Y-chromosome haplotype frequencies in 49 Eurasian populations, listed according to geographic region Analysis. Human Y-chromosome DNA haplogroup. Dominant Y-chromosome haplogroups in pre-colonial world populations, with possible migrations routes according to the Coastal Migration Model. In human genetics, a human Y-chromosome DNA haplogroup is a haplogroup defined by differences in the non-recombining portions of DNA from the Y chromosome (called Y-DNA). It represents human genetic diversity based on single-nucleotide polymorphisms (SNPs) on the Y chromosome.[1] Y-DNA haplogroups represent major branches of the Y-chromosome phylogenetic tree.
Y-chromosomal Adam is the name given by researchers to the patrilineal most recent common ancestor of all living humans at the root of this tree. Estimates of the date when Y-chromosomal Adam lived have varied significantly in different studies. Naming convention[edit] Y-DNA haplogroups are defined by the presence of a series of Y-DNA SNP markers. Long time customers of Family Tree DNA have seen the YCC-tree of Homo Sapiens evolve over the past several years as new SNPs have been discovered. Google Translate.
Haplotype. Many genetic testing companies use the term 'haplotype' to refer to an individual collection of short tandem repeat (STR) allele mutations within a genetic segment, while using the term 'haplogroup' to refer to the SNP/unique-event polymorphism (UEP) mutations which represents the clade to which a collection of potential haplotypes belong (the term clade referring to a set of people sharing a common ancestor).[3] Haplotype resolution[edit] The only unequivocal method of resolving phase ambiguity is by sequencing. However, it is possible to estimate the probability of a particular haplotype when phase is ambiguous using a sample of individuals.
Given the genotypes for a number of individuals, the haplotypes can be inferred by haplotype resolution or haplotype phasing techniques. These methods work by applying the observation that certain haplotypes are common in certain genomic regions. Y-DNA haplotypes from genealogical DNA tests[edit] UEP results (SNP results)[edit] Y-STR haplotypes[edit] Neanderthals Mated With Humans Outside of Africa | Wired Science. By Katie Scott, Wired UK It has been a long held belief that our human ancestors came into contact with Neanderthals, and recent findings not only confirm this, but also suggest exactly how “close” this contact was.
[partner id="wireduk" align="right"]Damian Labuda of the University of Montreal’s Department of Pediatrics and the CHU Sainte-Justine Research Center and team have found part of the human X chromosome comes from the Neanderthals and is found only in people outside of Africa. In a paper published in the July issue of the journal Molecular Biology and Evolution, the geneticists write: “We provide evidence of a notable presence (nine percent overall) of a Neanderthal-derived X chromosome segment among all contemporary human populations outside Africa”. The team analyzed 6,092 X-chromosomes “from all inhabited continents”. Their discovery confirms earlier hypotheses that early modern man and Neanderthals mixed and mated. Image: Andrew Griffith/Flickr Source: Wired.co.uk See Also: