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The title is the question. If additional specificity is needed I will add clarification here.

Are there any multicellular forms of life which exist without requiring the consumption (destruction) of other forms of life in some manner? Thus purely on inorganic material.

I do understand that the definition of life is a semantic distinction, so for this discussion I will assume the one Wikipedia provides:

"Life is a characteristic distinguishing physical entities having signaling and self-sustaining processes from those that do not, either because such functions have ceased (death), or because they lack such functions and are classified as inanimate. Biology is a science concerned with the study of life."

I am open to considering alternative suggestions.

Thank you.

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  • 2
    $\begingroup$ Closely related to the question can humans survive without eating life $\endgroup$ – Rory M Oct 11 '14 at 21:16
  • $\begingroup$ Many of deep sea organisms eat dead bodies. They do not catch other organisms alive. $\endgroup$ – 243 Jul 18 '15 at 0:29
  • $\begingroup$ Please include the question in the question. The title may or may not be the same, but the question should read coherently without reference to it. $\endgroup$ – David Apr 25 '18 at 19:20
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Yes, plants for example!

Autotrophs vs. heterotrophs

Plants are autotrophs while animals and fungi are heterotrophs. Have a look at the Wikipedia articles. In short, autotrophs organisms are organisms that synthesize their own compounds from inorganic compounds. Heterotrophs organisms are organisms that synthesize their own compounds from organic compounds.

Therefore, any multicellular plants are multicellular organisms that "exist without consuming other forms of life" (with the exceptions of carnivorous plants).

Consuming nonliving organic matter

Of course, many life forms feed on organic matter but only on non-living organic matter. Such life forms do not kill to feed. It is the case of all detritivores (such as earthworms) and decomposer such as fungi.

Competition vs predation

As @TechZen said, not consuming other organisms doesn't mean that the existence of an individual of this species is not causing the death of another individual (competition and parasitism that does not involve consuming the other individual).

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  • $\begingroup$ Aside from blocking out light, how do zooplankton cause the death of other individuals? $\endgroup$ – SolarLunix Jul 14 '15 at 5:09
  • $\begingroup$ Why do you want to take the "light blocking effect" out of the discussion? Zooplankton (by definition) are heterotrophs and therefore they eat other individuals. Zooplankton probably have tons of impact on their environment too (I am not an ecologist as you can tell) that likely affect other species. $\endgroup$ – Remi.b Jul 14 '15 at 5:16
  • $\begingroup$ Because what do they gain? Are they gaining resources because their numbers are high enough to smother other forms of life? Do they decompose the dead organisms and use them for energy like other plants do if there are dead organisms beneath them? $\endgroup$ – SolarLunix Jul 14 '15 at 5:24
  • $\begingroup$ I don't quite understand your point. Maybe you want to make sure to have a look at the wikipedia entry for zooplankton. $\endgroup$ – Remi.b Jul 14 '15 at 5:34
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There are multicellular organisms which do not actively eat other organisms, however, there are no organisms who do not kill other organisms, period.

Trees and other vertical plants evolved in the first place in a competition for sunlight. For plants, being in the shade is like smother or starving a human since they literally use sunlight to create and create food and oxygen. Plants carry out complex chemical war against a wide range of other life forms from microbes to other similar plants.

Plants don't eat other organisms, save indirectly, but they do kill.

All multicellular organisms have an immune system that wages and unrelenting slaughter against microbes which in turn are constantly assaulting multicellular organism.

Lastly, every individual organism and probably all strains and species, displace other individuals, strains or species just by existing. No energy is wasted in the biosphere. If something is living in one place or niche and then dies, the energy it was living on becomes available for something else. Conversely, while it lives it prevents other organisms from evolving to fill the niche, or as an individual moving into the physical niche.

Just by our very existence, we kill.

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  • $\begingroup$ Though there are saprophytic plants which "eat" dead organisms, parasitic plants (like this one: en.wikipedia.org/wiki/Sarcodes ) which feed off other plants, and even carnivorous plants that eat animals. $\endgroup$ – jamesqf Jul 14 '15 at 17:39
  • $\begingroup$ @jamesqf - Doesn't matter, what they eat or were, they displace something else and kill. All multicellular organisms have to constantly kill microbes to prevent being eaten by them. $\endgroup$ – TechZen Jul 17 '15 at 23:28
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No, there are no known multicellular organisms that depend exclusively on inorganic material.

Plants have been put forth as examples of multicellular organisms that do not "consume life", but that does not mean they don't depend on organic matter. Plants depend on nutrients found in the soil, and these nutrients come largely from decomposing organic material.

It is now early spring here and the local farmers have started spreading manure on the fields. That manure consists largely of dead plant matter digested (mainly) by cows.

Of course, a plant can live exclusively on inorganic nutrients, if you grow it hydroponically and exclusively give it inorganic fertilizers. Ammonia can be produced from nitrogen in the air through the Haber-Bosch process, and the rest, phosphates, potassium, sulphates etc. can be taken from mineral deposits, but this is rather artificial. Plants are, by and large, completely dependent on organic matter.

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