Human Auditory Ossicles as an Alternative Optimal Source of Ancient DNA

DNA recovery from ancient human remains has revolutionized our ability to reconstruct the genetic landscape of the past. Ancient DNAresearch has benefited from the identification of skeletal elements, such as the cochlear part of the osseous inner ear, that provide optimal contexts for DNA preservation; however, the rich genetic information obtained from the cochleamust be counterbalanced against the loss of valuable morphological information caused by its sampling. Motivated by similarities in developmental processes and histological properties between the cochleaand auditory ossicles, we evaluated the efficacy of ossiclesas an alternative source of ancient DNA. We demonstrate that ossiclesperform comparably to the cochleain terms of DNA recovery, finding no substantial reduction in data quality, quantity, or authenticity across a range of preservation conditions. Ossiclescan be sampled from intact skulls or disarticulatedpetrous bones without damage to surrounding bone, and we argue that, when available, they should be selected over the cochleato reduce damage to skeletal integrity. These results identify a second optimal skeletal element for ancient DNAanalysis and add to a growing toolkit of sampling methods that help to better preserve skeletal remains for future research while maximizing the likelihood that ancient DNAanalysis will produce useable results.