Ongoing challenges in protein sequences

Today, there are still hurdles that are yet to overcome before ancient proteins can bring the human family tree into complete focus. As of date, scientists have been able to infer the sequences of ancient proteins easily because they already collected DNA from Denisovans, Homo sapiens, and Neanderthals, allowing them to predict the sequences that appear in their mass-spectrometry indicators. Pääbo explained that fragments could be identified from known genome sequences, from either present-day humans or ancient organisms or people.

However, as scientists look back in time, they realized they would need to work out the amino acid sequences without a map, which is an ongoing challenge because proteins are deduced into small fragments, and samples are frequently contaminated with modern proteins to some degree, as said by Pääbo. Despite the existing issues that they need to sort out, progress in protein sequencing still shows no signs of slowing down.