🦷 A new study by @marinemorvan.bsky.social
High-throughput paleoproteomics method using MALDI-CASI-FTICR mass spectrometry to estimate biological sex from tooth enamel.
Great success on 130 individuals from medieval Great Moravia.
#Bioarchaeology #Archaeology #Proteomics #TooMS 😉 #Teammasspec
Matthew Collins
www.biorxiv.org
The data fit just fine if you assume these 6 samples being from a Denisovan subpopulation and not from a homo erectus relic population.
(Y|G)iannis P.
While we suspect incomplete lineage sorting as the main culprit for this result, an older admixture between Neanderthal and humans, a 'super-archaic' admixture into Denisovans or other scenarios could be at play.
Given the recent and upcoming recovery of ancient proteins from archaic human remains this would be something to keep in mind. The missmatch of autosomal, mitochondrial, Y chromosome and morphology-based trees is already complicated for these groups, proteins might add some to that complexity!
Interesting points!
If you look at the protein data alone, there are no recovered variants that support these samples being very divergent from modern humans, e.g. 'H.erectus like'. For comparison, the H.antecessor enamel had a variant, placing it as an outgroup to nean, deni, and present day humans
To me it's more likely that the 'homo erectus' variant emerged later, on top of the haplotype that carries the 'Denisovan-like' variant. So after an introgression event happened, if it did happen for this protein.
In fact, in the trees of enamel, collagen and other bone/dentin proteins, humans and Neanderthals appear closer to eachother as often as Neanderthals appear closer to Denisovans. This persists even when only looking at sub-saharan African populations, who have limited archaic introgression.
The two variants that are recovered are also found on the same protein!
If they were introgressed from homo erectus, they likely would have been linked together due to their physical proximity on the genome, and Denisovans would have inherited both.
In short we find that while only a few proteins are needed to resolve the tree between humans - chimpanzees - gorillas, the same cannot be said for the tree of modern humans - Neanderthals - Denisovans.
The final chapter of my PhD thesis, is finally published in GBE!
academic.oup.com/gbe/article/...
You can also read the earlier recommendation by PCI in a nice little summary here: evolbiol.peercommunityin.org/articles/rec...
#palaeoproteomics #phylogenetics
