Modifications

This is important to the genetic genealogist as non-recombinant DNA tests (mtDNA and Y-DNA) point to ancient people groups. Recombinant DNA (atDNA & X-DNA) gets diffused over time and is better suited for recent relationships. A genealogically useful time frame is approximately when surnames appeared and for which documentation is available, or about 1,000 years ago. Anything beyond that can be very difficult to substantiate. <em>(Surnames appeared in Europe approximately 1,000 years ago and were adopted in other places after that. Turkey didn't require surnames until 1934. Likewise, the availability of documentation varies over place and time.)</em> Y-DNA STR tests, due to its higher mutation rates, and atDNA can effectively represent recent relationships.

This is important to the genetic genealogist as non-recombinant DNA tests (mtDNA and Y-DNA) point to ancient people groups. Recombinant DNA (atDNA & X-DNA) gets diffused over time and is better suited for recent relationships. A genealogically useful time frame is approximately when surnames appeared and for which documentation is available, or about 1,000 years ago. Anything beyond that can be very difficult to substantiate. <em>(Surnames appeared in Europe approximately 1,000 years ago and were adopted in other places after that. Turkey didn't require surnames until 1934. Likewise, the availability of documentation varies over place and time.)</em> Y-DNA STR tests, due to its higher mutation rates, and atDNA can effectively represent recent relationships.

''' Haplogroup '''

''' Haplogroup '''

A haplogroup is a large group of people related to you as defined by a SNP which occurred in the mtDNA or Y-DNA of one of your ancestors. The overall family tree for humans is called a phylogenetic tree <ref>[http://isogg.org/tree/index.html Y-DNA Haplogroup Tree 2016]</ref> <ref>[http://www.phylotree.org/ Comprehensive phylogenetic tree of global human mitochondrial DNA variation]</ref> and each of its branches represents a more recent haplogroup. The most ancient mtDNA haplogroup known is "L". Everyone who has ever lived is believed to descend from mtDNA haplogroup L, making it the largest haplogroup. Conversely Y-haplogroup A encompasses every man who has ever lived. Most men in America belong to the much more recent haplogroup R which is thought to have appeared about 20,000 years ago. More recent haplogroups represent smaller subgroups of the human race. Scientists are discovering even more recent haplogroups, which will make DNA even more useful to the genealogist. Each haplogroup is defined by one or more SNPs and the most recent haplogroup is defined by what is called a terminal SNP. A terminal SNP will be redefined as more recent ones are discovered. <ref> [https://customercare.23andme.com/hc/en-us/articles/202906900-More-about-Haplogroups 23and Me More about Haplogroups]</ref>

A haplogroup is a large group of people related to you as defined by a SNP which occurred in the mtDNA or Y-DNA of one of your ancestors. The overall family tree for humans is called a phylogenetic tree <ref>[http://isogg.org/tree/index.html Y-DNA Haplogroup Tree 2016]</ref> <ref>[http://www.phylotree.org/ Comprehensive phylogenetic tree of global human mitochondrial DNA variation]</ref> and each of its branches represents a more recent haplogroup. The most ancient mtDNA haplogroup known is "L". Everyone who has ever lived is believed to descend from mtDNA haplogroup L, making it the largest haplogroup. Conversely Y-haplogroup A encompasses every man who has ever lived. Most men in America belong to the much more recent haplogroup R which is thought to have appeared about 20,000 years ago. More recent haplogroups represent smaller subgroups of the human race. Scientists are discovering even more recent haplogroups, which will make DNA even more useful to the genealogist. Each haplogroup is defined by one or more SNPs and the most recent haplogroup is defined by what is called a terminal SNP. A terminal SNP will be redefined as more recent ones are discovered. <ref> [https://customercare.23andme.com/hc/en-us/articles/202906900-More-about-Haplogroups 23and Me More about Haplogroups]</ref>

''' Haplotype '''<ref>[http://isogg.org/wiki/Haplotype Haplotype]</ref> <ref>[http://isogg.org/wiki/Ancestral_haplotype Ancestral haplotype]</ref>

''' Haplotype '''<ref><[http://isogg.org/wiki/Haplotype Haplotype]</ref> <ref><[http://isogg.org/wiki/Ancestral_haplotype Ancestral haplotype]</ref>

We use a narrow definition for haplotype for genealogical research. It is specific to Y-DNA and, simply put, it is a set of numbers that are unique to the individual who took the test &ndash; a "signature" for that person. Others who have similar or identical haplotypes are almost certainly related, though "genetic drift" can cause false positives with unrelated individuals who have similar haplotypes. The numbers are called "alleles" and represent the number of times a base pair is repeated. Whereas a haplogroup denotes a branch on the human tree, a haplotype belongs to one individual and those very closely related to him.

We use a narrow definition for haplotype for genealogical research. It is specific to Y-DNA and, simply put, it is a set of numbers that are unique to the individual who took the test &ndash; a "signature" for that person. Others who have similar or identical haplotypes are almost certainly related, though "genetic drift" can cause false positives with unrelated individuals who have similar haplotypes. The numbers are called "alleles" and represent the number of times a base pair is repeated. Whereas a haplogroup denotes a branch on the human tree, a haplotype belongs to one individual and those very closely related to him.