The Y chromosome has been studied intensely and variations have been divided into Human Y-chromosome DNA haplogroups, based upon the results of the number of alleles in certain positions called markers. These "markers" have been chosen for their demonstrated ability to predict the haplogroup of the tested individual.
The Y chromosome has been extensively researched, and its variations have been categorized into Human Y-chromosome DNA haplogroups based on the number of alleles at specific locations called markers. These "markers" were chosen because they can accurately determine a person's haplogroup.