Complex sentence: Today, this haplotype can be found in 80% of Europeans and Americans of European ancestry, though the percentage of the population who are lactase persistent in sub-Saharan Africa and Southeast Asia is very low.
Split into simpler sentences: Today, this haplotype can be found in 80% of Europeans and Americans of European ancestry. On the other hand, the percentage of the population who are lactase persistent in sub-Saharan Africa and Southeast Asia is very low.