Complex sentence: Due to the decomposition of the DNA, it could not be determined with certainty whether the bone belonged to Günther Messner-it was possible that the bone could have come from climbers who died on the mountain in 1962.
Split into simpler sentences: Due to the decomposition of the original DNA, it could not be determined with certainty whether the bone belonged to Günther Messner. It was possible that the bone could have come from the remains of climbers who perished on the mountain in 1962.