Each tea bag has traces of up to 400 different species of insects. And it’s for a good reason

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A group of German researchers has carried out a study in which they have found traces of DNA from about 1,200 species of insects and other arthropods in tea bags marketed in the country. The existence of traces of various “captured” animals in our food is not new, but the procedure that has found these is what turns the curious finding into good news.

environmental DNA.
The analysis of Environmental DNA (eDNA) It allows analyzing any sample of an environment (such as mud, water, dust…) in search of DNA traces of living beings that have passed through this environment. This DNA may have been left by the saliva of an animal, by its blood, feces or other secretions, roe, remains of a molt, among others.

This taxonomic analysis methodology allows identification of a large number of species that inhabit an environment. To simplify this analysis, researchers often focus on species with common phylogenetic features. In this example, the researchers focused on DNA belonging to arthropods, looking for segments of the DNA chains common to these animals in order to find them among the samples analyzed.

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What exactly has been found.
The team found these traces of eDNA in different infusions and herbs that they analyzed (mint, chamomile, parsley and green tea). They found 3,264 arthropod tracks from 1,200 different species, with each sample containing between 200 and 400 of these tracks. It was in a sample of green tea that the researchers found a greater number of traces of these animals.

They analyzed 40 samples purchased from German supermarkets. eDNA analysis enables searches that span a broad spectrum of life. An “outlier” element highlighted by scientists in the article published in the magazine Biology Lettersis the good state of conservation of the genetic information in dry plants, which “shows a high temporal stability, which opens the plant archives as a historical source of the eDNA of arthropods”.

What implications does it have?
Therein lies the importance of the study. If someone was concerned that the presence of traces of arthropods in their tea would imply a lower quality of it or a health risk, they can breathe easy.

Environmental DNA analysis has become a front-line weapon in biodiversity conservation, and knowing that dry leaves are a stable source of this information is good news for experts. In words of the authors“the possibility of being able to collect eDNA almost anywhere in the environment (in water, in soil or in plants) has given biomonitoring, the observation and surveillance of animals and plants, enormous progress in recent years .

An improved strategy.
This method has two advantages. The first is that it works as a “trawl fishery” being able to identify hundreds of species from a small sample as has been done with this study. This differentiates it from mere observation, the way in which we have traditionally found the species that we have been identifying and cataloging throughout history.

The second advantage is that it is not an intrusive method and does not affect the species it analyzes. To study the DNA of a species in its environment, it is often necessary to capture it. This takes the specimen away from its land, which we do not want with vulnerable or endangered species, when it does not require the specimen to be sacrificed. The use of traps to capture specimens can also lead to the capture of animals of other species, with the consequent environmental damage.

Where else to look?
It will be interesting to see the implementation of this methodology given the possibility of finding traces of animals yet to be discovered and identified. It could even lead us to find already extinct species and other curiosities. Plants from all over the world can be analyzed years later to find remains of all kinds of species that we can imagine.

Image | Chikilino

A group of German researchers has carried out a study in which they have found traces of DNA from about…

A group of German researchers has carried out a study in which they have found traces of DNA from about…

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