Among the most visible species threatened with extinction are leopards, tigers, elephants, orangutans, gorillas and rhinoceroses. What may be of even greater consequence, however, are the millions of species we cannot see, the microbiome of the Earth which is essential to the life of plants and animals worldwide. As the Sixth Great Extinction proceeds, our attention ought to turn as much to these tiny creatures as to the ones who make good television commercials because we can relate to them and because they are such large and grand products of evolution on our planet.
In a recent paper, scientists outline the stakes:
Microbes regulate the major biogeochemical cycles on Earth, to the extent that signatures of microbial biogeochemical activity underpin efforts to discover extraterrestrial life. By regulating global nutrient cycles, greenhouse gas exchange, and disease transmission and protection, the Earth microbiome provides an essential life-support system to our planet. A functioning Earth without a functioning microbiome is nearly unimaginable.
Back in 2017 I asked, "Which species can we do without?" I provided a preliminary but not very helpful answer: "The answer so far is the ones that have already gone extinct while we humans have been around on the planet." But that leaves unanswered which of the remaining species we could do without. I observed:
If you consider that the broader world with which we interact has millions of species of which we are not aware, it becomes apparent that the Sixth Great Extinction is a rather clumsy and thoughtless way to play Russian roulette with human existence. We could easily cause an organism essential to our survival to go extinct without even realizing it.