Barcoding the Critters?

A shortage of taxonomists as made it very difficult to establish the rate at which species (especially the members who are not megafauna) are becoming extinct. A Canadian, Paul Hebert, was able to quickly distinguish between closely-related moth species by using a mitochondrial gene (cytochrome oxidase 1) that is present in all aerobic (oxygen-using) life (https://www.theguardian.com/environment/2020/oct/07/counting-the-species-how-dna-barcoding-is-rewriting-the-book-of-life-aoe). Bar coding this sequence was cheap and could be used for all animals. Bizarrely, if the endosymbiotic origin of the mitochondrion is correct (the idea that this important ATP-producing organelle is derived from a bacterium that has taken up residence in the cells), animals would be being barcoded on the basis of an enzyme from what was initially a symbiotic organism. In sexual reproduction, animals get their mitochondria in the cytoplasm of the egg provided by their mother. An equivalent section of DNA could be used to barcode plants and fungi for classification purposes. Hebert (strangely) was initially criticised but his DNA barcoding technique is now the main method used to assess biodiversity. The technique has been much used by two Americans, Janzen and Hallwachs, in Guanacaste in Costa Rica (which has 4% of the world's biodiversity). Their International Barcode of Life project has already coded 750,000 species and aims to raise $180m to code a further 2 million. As well as telling us about the rate of extinction in this, the planet's 6th mass extinction, the data is likely to help identify species that can be beneficial to humans. I think that this is an excellent project but I am just minded of once reading (I don't now if it is true), that there were more undiscovered species in a cubic metre of soil than in the Amazon rainforest. Most of these, of course, would be bacteria and we have hardly touched these important organisms, some of which must also be disappearing from the Earth.