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| Got eDNA/aDNA? |
In the previous post of this series I mentioned the wide range of years involved in the issue of "the human family" even though current main stream thinking is biased against those years:
The span of years contemplated in this series (2-3 million) is not out of bounds:
"Sahelanthropus tchadensis is one of the oldest known species in the human family tree. This species lived sometime between 7 and 6 million years ago ..."
(Smithsonian National Museum, emphasis added). Getting a bit more specific about the genetics involved:
"DNA also shows that our species and chimpanzees diverged from a common ancestor species that lived between 8 and 6 million years ago."
(Human DNA Found In 2-3 Mya eDNA? - 6). I mention that because currently in the general public any acceptable suggested 'age' for 'human DNA' is in the thousands rather than in the millions.
Currently, generally older sequences of DNA that contain 'human DNA' matches is presumed to originate in the lab or research site where 'skin' from human researchers is thought to have contaminated those samples.
With the advent of eDNA it is time that researchers become really adept at quality sampling, because some scientists indicate that it is possible:
"The labs and protocols are designed to safeguard these precious samples from contamination. A strict working procedure guides researchers through the labs. This system, combined with positive air pressure, full personal protective equipment and a meticulous cleaning regime, provides the environment essential for preventing cross-contamination, whether from modern human DNA or between different eDNA samples."
(Cambridge eDNA and aDNA labs). It is time to make sure because eDNA is a growing realm for discovery.
There is even a call for papers on the subject by the journal Nature:
"Environmental DNA (eDNA), the genetic material shed by organisms into their surroundings, has emerged as a transformative tool for biodiversity monitoring, offering cost-effective and non-invasive methods to detect species and assess ecosystem health. This approach enables rapid insights into species presence, community composition, and ecological dynamics across aquatic, terrestrial, and aerial environments.
This collection invites original research that advances eDNA science through innovations in sampling, extraction, and analysis, eDNA based biodiversity monitoring, applications in conservation biogeography for detecting invasive species and guiding habitat restoration, and studies on the influence of environmental stressors on eDNA persistence and detection. Contributions exploring metabarcoding, metagenomics, ecological modelling, airborne eDNA, eRNA, and population genetics are particularly encouraged."
(Environmental DNA as biosignatures).
Check out more examples of 'human DNA' in eDNA via today's appendix (APNDX 7).
The previous post in this series is here.
