Except for bacteria, surviving basically involves two processes that a creature made up of eukaryotic cells must undertake: either breathing or capturing sunlight.
Ironically, It is thanks to metabolic innovations initiated by bacteria that we have air to breathe..
Eukaryotes
All animals based on eukaryotic cells (plants, animals, fungi) survive thanks to one of the two metabolic strategies mentioned above: photosynthesis or aerobic respiration. But that's not the case with bacteria, which are much more diverse than us, as explained by Steve Johnson in his book The Ghost Map:
They directly consume nitrogen from the air, extract energy from sulfur, are capable of living at extremely high temperatures in the waters of underwater volcanoes, and concentrate by the millions in a single human colon.
Bacteria are the most widespread life form in terms of biomass, and they are also the most efficient organisms. Without them there would be no air for us to breathe.:
With the exception of a few unusual compounds (including snake venom), bacteria can process all the molecules of life, making them an essential source of energy for the planet and its primary recycling mechanism.
However, most microorganisms are heterotrophs (or more precisely, chemoorganoheterotrophs), using organic compounds as sources of carbon and energy. Heterotrophic microorganisms live off food stolen from living hosts (as commensals or parasites) or off dead organic matter of all kinds (saprophages). Most pathogenic bacteria are heterotrophic parasites of humans or other eukaryotic species..
Bacteria have existed since the beginningThe rest of the more complex organisms only exist thanks to them. We are apprentices in the realm of survival, and that's why we are less diverse, less adapted, less numerous, and easier to eradicate if something changes in the ecosystem.
And yet, Not even our eyes are designed to see them with the naked eye.To know of their existence, we need technology, or we need bacteria to concentrate in the order of ten million per milliliter of water (0.4 % of a cup).
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The news
Breathe or capture sunlight: you can only do that to survive (unless you are a bacteria)
was originally published in
Xataka Science
by
Sergio Parra
.