Neanderthals did not likely consume Physcomitrium patens – a model moss species

Abstract

13 14 15 16 17 18 19 20 21 22 This manuscript is discussing the method of Weyrich et al., 2017, “Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus”. When studying the dietary profile of a Neanderthal specimen from El Sidrón cave (Spain) by sequencing ancient DNA present in calcified dental plaque (calculus) the authors identified a wide-range of potential food sources, including woolly rhinoceros, mushrooms, pine nuts, and moss – namely the less-than-abundant model species Physcomitrium patens. We doubted that Neanderthals were actually eating P. patens. By analyzing the ancient DNA reads using different mapping methods, we show likely a misinterpretation based on the previously used methods. The probability of Neanderthals eating P. patens is the same as eating rice or tomato. However, neither crop was grown in Europe at the time Neanderthals thrived. 23 24 Did Neanderthals eat moss? 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Deep sequencing of ancient DNA (aDNA) derived from digestive tracts and dental calculus has been used in recent years to infer dietary habits of past animals and humans. When studying the dietary profile of a Neanderthal specimen from El Sidrón cave (Spain) by sequencing ancient DNA present in calcified dental plaque (calculus), Weyrich et al. identified a wide-range of potential dietary food sources, including woolly rhinoceros, mushrooms, pine nuts, and moss 1. These species were identified using a MALTx approach, similar to BLASTx, which translates DNA sequences into proteins and runs comparisons to the NCBI non-redundant (nr) database (2014). Care was taken to ensure false mapping was not driving the results. For example, only DNA sequences > 50 bp were included in downstream analysis, and spurious mapping was filtered using the default last common ancestor (LCA) filter in MEGAN5 2 prior to assessment. Additionally, assignments were ignored if the reference genome contained known human DNA contamination, the eukaryote was observed in a mock microbial metagenome, or the DNA was present in a laboratory blank control. Other contemporaneous aDNA analysis papers used similar approaches 3. 39 bioRxiv preprint doi: https://doi.org/10.1101/2022.01.26.472964; this version posted January 28, 2022. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. …