A new study highlights how little is known about microbes – the hidden majority of life on earth.
Life on the planet depends on an enormous amount of bacteria, fungi and other small organisms. They generate oxygen, keep the soil healthy and regulate the climate. Microbes play an important role in food production, such as cheese, beer, yogurt and bread.
But despite its importance to human life and the health of the Earth, a new scientific paper has shown us ‘deep ignorance’ about microbial biodiversity and how it is changing.
“We have no idea whether global microbial diversity is increasing, decreasing or staying the same,” said David Thaler, a biologist at Basel University and author of the article. ‘Most scientific articles tell us new facts. It’s a different kind of paper; it answers nothing but asks a new question. ”
Many plant and animal populations are declining rapidly, with about 1 million species at risk of extinction, according to a 2019 UN-backed report. Plants and animals are counted over time to monitor how their populations change.
Microbes often occur in extreme environments – surviving at the bottom of the ocean, deep frozen in glaciers and even in a toxic volcanic lake – making it difficult to study. Although poorly understood, bacteria and other small organisms are widespread in the deep biosphere below the earth’s surface.
Prof Frederick Cohan, a microbial ecologist at Wesleyan University, Connecticut, who reviewed the study before publication, said that although extinctions of animals and microbes can go hand in hand, new bacterial species can form so high that they can increase regardless of extinctions. of plants and animals.
“When a mammalian species becomes extinct, we should expect all the microbes that are primarily or exclusively dependent on that species to become extinct as well,” he said.
“On the other hand, microbial ecologists like me who study the diversity of extremely closely related bacteria find that new bacterial species are always forming. There are always new ways in which bacteria can spread the existing resource to make new species possible. ”
The article discusses how to study changes in global microbial biodiversity, including monitoring small sequence changes similar to those used to detect Covid-19 variants, and analyzing the molecular machinery of gene transfer. Researchers hope the study will inspire others to investigate.
“Socrates calls ignorance of what we do not know ‘profound ignorance’. This kind of ignorance is also called ‘unknown strangers’ by former US Secretary of Defense Donald Rumsfeld. This article identifies what, or was, from now on a biological unknown, ‘Thaler said.
Jesse Ausubel, director of Rockefeller University program for the human environment, a sponsor of the study, said: ‘Linnaeus started his Natural System in 1735, almost 300 years ago, and we do not yet have a complete list of the plants and animal species he began cataloging. It will not be easy to do something similar with probably 1,000 times as many microbes and measure the changes. ”
Microbes in the human body have been linked to conditions ranging from obesity and type 2 diabetes to food intolerance and anxiety. The consequences for the planet of humanity’s ignorance of how the microbial life changes are also unclear, the study finds.
About 90% of the total weight of the organisms in the ocean are microbes, according to the Census of Marine Life in 2010. Microbes are critical in capturing carbon, they break down organic matter and form the basis of the food web.
Viruses such as Covid-19 and other microbes, such as the Yersinia pestis bacteria responsible for bubonic plague can cause diseases and are increasingly linked to the destruction of the natural world. Understanding changes in the abundance and diversity of microbes is important for understanding the health of the planet.
‘There is still no agency that monitors the state of the microbial world, and no WWF or nature conservation for microbes. “Perhaps we will soon realize and rectify our neglect and lift our respect for the diversity of microbial life,” Ausubel said.
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