But perhaps most surprisingly, DNA analysis revealed Ludwig’s Y chromosome doesn’t match any of the five modern-day relatives carrying the same last name. That finding indicates the birth of a child resulting from an extramarital affair in Ludwig’s direct paternal line. Meanwhile, on his maternal side, Ludwig shares ancestry with James Watson, co-discoverer of the double helix structure of DNA.
Hair samples
An international research team collected and authenticated eight hair samples believed to belong to the composer from public and private collections in the UK, continental Europe and the U.S. The team says they relied on recent improvements in ancient DNA analysis that have enabled whole-genome sequencing from small quantities of historical hair.
They found at least two of the locks did not belong to Ludwig, including a famous one once believed to have been cut from the recently deceased composer’s head by the 15-year-old musician Ferdinand Hiller. Previous analysis of the “Hiller lock” supported the suggestion that Beethoven had lead poisoning, partially explaining his health complications. However, this research team showed that lock originated from a woman.
One of the five positively identified samples was hand-delivered from Ludwig himself to pianist Anton Halm in April 1826. Another was so well-preserved that the research team was able to sequence Ludwig’s whole genome.
Genealogical surprise
Using the hair samples, the research team initially planned a routine analysis of Ludwig’s paternal line by examining his Y chromosome. They contacted living descendants of Aert Van Beethoven (1535–1609), Ludwig’s supposed 5th great-grandfather. Five descendants of Aert agreed to take a DNA test—but that’s here it gets messy.
To the researchers’ surprise, the descendants were not a match. According to FamilyTreeDNA (FTDNA), the five present-day descendants of Aert Van Beethoven belong to haplogroup R1b, whereas Ludwig belongs to haplogroup I1. Those two father lines are separated by over 45,000 years, since around the time humans left Africa.
This strongly indicates that there was an extra-pair-paternity (EPP) event in Ludwig’s father’s line. Somewhere, starting with Ludwig’s father Johann and going up his family tree to his 5th great grandfather Aert, one of these Beethovens wasn’t a biological ancestor to Ludwig.
The team showed that Aert was indeed the father of his two sons Jan and Lambert, but could not definitively prove Aert was the father of Hendrik, Ludwig’s 4th great-grandfather. Assuming Aert was Hendrik’s true father, perhaps Ludwig’s grandfather Lodewijk was not his true biological grandfather.
Meanwhile, on his mother’s side, Ludwig’s genealogy traces back to the Rhineland-Palatinate region in Germany in the 1600s. Mitochondrial analysis showed that he belonged to a common European haplogroup called H1b1-T16362C.
