Task: Question Answering
Input (English): Passage: Napoleon acknowledged one illegitimate son: Charles Léon (1806–1881) by Eléonore Denuelle de La Plaigne. Alexandre Colonna-Walewski (1810–1868), the son of his mistress Maria Walewska, although acknowledged by Walewska's husband, was also widely known to be his child, and the DNA of his direct male descendant has been used to help confirm Napoleon's Y-chromosome haplotype. He may have had further unacknowledged illegitimate offspring as well, such as Eugen Megerle von Mühlfeld by Emilie Victoria Kraus and Hélène Napoleone Bonaparte (1816–1907) by Albine de Montholon. Question:  DNA from Alexandre Colonna-Walewski's descendants has been used to confirm what attribute of Napoleon's?
Output (English): Napoleon's Y-chromosome haplotype