Complex sentence: A notable member of the T haplogroup is Thomas Jefferson; his Y-chromosomal complement was studied in an attempt to resolve the controversy over whether he had fathered the mixed-race children of his slave Sally Hemings.
Split into simpler sentences: A notable member of the T haplogroup is Thomas Jefferson. The Y-chromosomal complement of the Jefferson male line was studied in an attempt to resolve the controversy over whether he had fathered the mixed-race children of his slave Sally Hemings.