What did the first single-cell life on Earth eat?
Asked by
ETpro (
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October 20th, 2013
Eating and eliminating is part of the very definition of life. So the first living things on Earth had to eat something.
Today, Earth’s food chain is one big circle. The tiniest single-cell life is eaten by slightly larger living animals and plants, which are then eaten by larger ones and so on up to the great herbivores which are eaten by the alpha predators. The alpha predators and great herbivores then die, decay, and feed the plants and the single-cell life forms. But before there was any of that life to feed on, what did the first prokaryotes eat?
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14 Answers
Lichens eat minerals from the rocks on which they grow (supplementing with solar energy from the chlorophyll-rich symbiote). I imagine the first organisms ate something like that.
They didn’t “eat”, they absorbed energy from sunlight.
Some were chemotrophic, obtaining energy through chemosynthesis, and some were phototrophic, gaining energy through photosynthesis. This last process is how we ended up with so much oxygen on Earth. Check out stromatolites if you’re interested. They are pretty cool.
Edited by me – @glacial said what was on my mind.
Hamburgers and fries. Of course.
Called for Domino’s Pizza delivery.
The very first were chemotropic, because that would be all that was around. Phototropic came about later and were hugely sucessful, leading to our current oxygen atmosphere as @glacial mentioned, but these didn’t come about for quite a long time (current thinking puts it at about 1 billion years after the start of life), as the machinery necessary for harvesting light is very complex. Once they did, though, they took off like a shot, leading to what is now known as the “oxygen catastrophy” and possibly the largest extinction event ever.
Poisoning their own atmosphere… what can they have been thinking? ;)
Crazy bacteria, no forethought at all. Luckily we totally don’t have that problem.
@laureth I’m not so sure I’m lichen the idea of going out and eating rocks. Besides, I woldn’t lichen them to the first life forms.
@zenvelo All life carries on the consumption of nutrients, respiration and reproduction. Those are the things that set life apart form non-living things. “Eating” is necessary to acquire the stuff to self replicate. Without taking in the raw materials to self replicate, each copy would be half the size of its parent generation, and they would soon become so small there would not be enough atoms in them to form the requisite structures of a living organism.
@glacial Of course I am interested in stromatolites. They rock.
@jaytkay It’s the thought that counts.
@snowberry What? Do ya think they were as stupid as humans?
@Tropical_Willie At least they didn’t give their business to that bigot that owns Papa Johns.
@BhacSsylan & @glacial How true. Puts us in our place, doesn’t it.
@filmfann Ha!
I still wish to know how its first sexual experience was like. lol
@mazingerz88 I reckon asexual reproduction must be intense on many levels.
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