Our current knowledge on the use of plants by our species during the Paleolithic (2,5 mln – 12000 Years ago) are documented thanks to fragments of plants, phytoliths and microfossils, as well as biomarkers from food preparation tools and dental calculus, but are quite limited due to the poor preservation of identifiable plant remains and the lack of adequate methods for their detection and identification.

However, a fairly recent international study shows us how, thanks to the analysis of the DNA preserved in the sediments of the caves (unique environments where the full effect of the elements on the accumulated organic materials can be mitigated), we are now able to identify plants even in the absence of visible remains, as had already been done for animal and human remains in various excavation sites.

It all started from the analysis of the Upper Paleolithic settlement (39.000 – 24.000 Years ago) in the Aghitu-3 cave in Armenia, where artifacts of various kinds have been found, as well as coals and pollens, generally very useful for reconstructing the habits of those who lived on that site.

The metabarcoding technique has been applied (1) sedimentary DNA (sedaDNA), combined with pollen data.

The temporal reconstruction obtained highlights a stratification of plant abundance and diversity in which the data reflect greater diversity in periods of greater human activity.
This also combines in the same periods with a lower pollen concentration, indicating that the presence of plants in the cave during the occupation was of an intentional nature.

Proof of this, DNA analysis of the plants present (identifiable with 10 families, 20 genres and 6 different plant species) shows that they were for food or aromatic use (in total 15 edible plant taxa, seven of which are aromas), doctor or technician (fabric dyeing).

This gives us indications not only on the ability of our Paleolithic predecessors in knowing how to choose and distinguish the plants useful to them, from potentially toxic or non-exploitable ones, but also of the enormous potential of the environment surrounding the cave.

The analysis of sedaDNA vegetation in cave sediments, used for the first time in this study, represents an important innovation in the field of research on plants used by prehistoric humans and offers us, then, new opportunities to understand details of past human behavior, including the importance and use of plants.

(1) metabarcoding= DNA coding that allows the simultaneous identification of many different species within the same sample. The main difference between barcoding and metabarcoding is that the latter does not focus on a specific organism, but aims to determine the composition of species within a sample.

Source: “Sedimentary ancient DNA metabarcoding as a tool for assessing prehistoric plant use at the Upper Paleolithic cave site Aghitu-3, Armenia” Anneke T.M. ter Schure, et all, 2022, https://doi.org/10.1016/j.jhevol.2022.103258