In the study of the ancient ancestry of humans, scientists focus on “haplogroups”, the classification of all humans into ancient family clans based on the unique pattern of genetic markers called “SNPs” found their DNA. SNPs are small changes in the DNA which occur naturally over time. Once a SNP occurs, it becomes a unique lineage marker that is passed down to all future generations. Humans who have descended from the same ancient family clan will share the same pattern of SNPs.
Using SNPs, scientists have been able to plot the haplogroups of all humans living today into a single phylogenetic tree of mankind which shows how all humans are connected to each other in a complex worldwide tree that stems from Africa over 150,000 years ago.
Dozens of haplogroups have been discovered to date, each haplogroup representing a major branch in the phylogenetic tree of mankind.
Each haplogroup can be further refined into “subclades” (finer sub-branches of the tree). As new SNPs are discovered, the phylogenetic tree becomes increasingly detailed with finer branches and enhanced resolution. By testing individuals from around the world and analyzing their precise placement in the phylogenetic tree of mankind, scientists are attempting to piece together the intricate puzzle of ancient human connections and migrations.
Haplogroups are named using capital letters of the alphabet (i.e. A, B, C…, etc.). Each haplogroup can be further subclassified into subclades. Subclades are named using numbers and lower case letters following the initial haplogroup letter (i.e. R1b1b2a2b1a is a subclade of haplogroup R).
In human population genetics, the two types of haplogroups studied are Y-DNA and mtDNA haplogroups:
The DNA Ancestry Project allows people to test their DNA in order to predict or confirm which Y-DNA and mtDNA haplogroup they belong and to gain insight into their ancient ancestral origins.
The Y-DNA haplogroup can be predicted us Y-DNA STR testing, but the only way to confirm the Y-DNA haplogroup is through Y-DNA Backbone SNP testing. The mtDNA haplogroup can be predicted by testing the HVR-1 and HVR-2 regions. The mtDNA haplogroup and subclade is confirmed by testing the Coding Region in addition to HVR-1 and HVR-2.