Final answer:
About 4% of men in Central Asia may be descended from Genghis Khan, which is around 16 million men with Y-chromosomes linked to his lineage.
Step-by-step explanation:
a. 4%. A genetic study suggests that approximately 4% of the male population in Central Asia may be descendants of Genghis Khan. This percentage equates to nearly 16 million men who carry Y-chromosomes similar to those historically associated with Genghis Khan and his lineage. The Mongol Empire, under Khan's rule and that of his successors, expanded across much of Eurasia and resulted in significant genetic contributions in the regions he conquered.
His policies and practices, including the assimilation of conquered people and merit-based promotion within his army and administration, may have contributed to the widespread distribution of his genetic lineage.