It seems that every week there are exciting new findings from ancient DNA research. This is wonderful news, because we’re learning incredible things about the relationship between humans and Neandertals, the prehistory of ancient populations, and even previously unknown hominins. But on the flip side, we’re also seeing news reports of extremely questionable results, and I’ve gotten more than one inquiry recently from people excited or confused by them. I though it would be a good idea to write a bit about how regular people can figure out whether a study is legitimate or not.
The first step in distinguishing good ancient DNA studies from bad ones is the same as distinguishing pseudoscience from legitimate science in general: ask where the results are published. Are they in a peer-reviewed journal? Or does the author present it as “science by press release,” stating something like:
The next steps require you to know a bit about ancient DNA itself, and how research is conducted. What most casual readers may not understand is how difficult recovering DNA from ancient remains is….and how easily it can become contaminated.
The TL;DR version is that for an ancient DNA study to be considered authentic, at minimum it:
- Must be conducted in the proper facilities
- Must be conducted by personnel practicing sterile techniques
- Must utilize negative controls
- Must have a subset of results reproduced by an outside laboratory
- Must yield phylogenetically reasonable results (or produce extraordinary evidence to support unusual results), that match the characteristics of ancient DNA.
- Must conform to any additional standards necessary, depending on the sample and experimental design