In human genetics, Haplogroup A (M91) is a Y-chromosome haplogroup.

Haplogroup A is localized to Africa and represents the oldest and most diverse of the human Y-chromosome haplogroups. It is believed to be the haplogroup corresponding to Y-chromosomal Adam.

It is common among the Khoisan people, including the Bushmen and the Hadza of Tanzania. It is also present in Ethiopia in significant numbers. Semino et al. 2001 found haplogroup A in 10.3% of an Oromo sample and 14.6% of an Amhara sample. They also found the haplotypes in these Ethiopian samples to be different from those in their Khoisan sample, "in agreement with an ancient divergence from the same ancestral population."

External links

• Spread of Haplogroup A, from National Geographic

Human Y-DNA haplogroups