Haplogroup K is a human mitochondrial DNA haplogroup, which means it is passed down from mothers to their children. It is believed to have originated around 20,000 to 30,000 years ago in the region of Western Asia. This haplogroup is associated with various populations across Europe, the Middle East, and parts of Asia. Haplogroup K is significant in genetic studies as it helps trace maternal ancestry and migration patterns. It is a subclade of haplogroup U and has several branches, including K1, K2, and others, each representing different lineages and historical movements of populations.