In the heterotrophic theory for the origin of life, we imagine a primordial soup that is rich in organic compounds and the first organisms emerge eating those compounds. Since these organic compounds are external to this early organism, this early organism is a heterotroph. But it is not like any current heterotroph since it doesn't eat other organisms or their byproducts. Is there a special name for this 'type-0' heterotroph?

At some point, some organisms emerge that eat other organisms (i.e. eat those 'type-0' heterotrophs that are already around). These new organisms are more like the standard heterotrophs of today. Is there a special name for this 'type-1' heterotroph?

I am looking for the terminology that distinguishes the heterotroph that eats only organic compounds that are non-organisms in the primordial soup ('type-0') versus the heterotroph that eats other organisms ('type-1').

Normally, I could call the 'type-0' a primary heterotroph and the 'type-1' a secondary heterotroph. But we usually think of primary heterotrophs as things that eat autotrophs and at the start of the heterotropic theory, there are no autotrophs to eat. The primordial soup of the environment itself is the 'producer'.

If there is no standard name, would it be strange to call the 'type-0' heterotrophs as 'nullary heterotrophs' and the organisms that eat other organisms as 'non-nullary heterotrophs'?


1 Answer 1


@Artem, it's been a while! Good to see you back on Biology.SE.

I doubt that any rigorous terminology exist to describe these "type-0 heterotrophs" living on "non-organismic" organic compounds.

You might be assuming that early organic matters can naturally be categorized as being fundamentally alive vs fundamentally non-living. It is more a question of philosophy of the definition of life than anything else but, to my experience, most authors who wrote about the definition of life tend to consider early life as a spectrum from "definitely not living" to "definitely a living thing". The existence of this spectrum questions the need for the terminology you are looking for.

  • $\begingroup$ Actually it can, but most authors just wants to grant a safe passage for themselves just in case some later experimental evidence shows their hypothesis as being wrong by assuming there is no such thing as a clear distinction between life and non-life. The fact is that such a distinction CAN, in reality, be made if you have a sufficiently advanced understanding of what Life is vs. what it's not, but since we don't have enough evidence for it people just like to assume such a distinction is impossible in both principle and reality. $\endgroup$ May 28, 2020 at 14:46
  • $\begingroup$ I just wish to add that the core of the problem is the fact we don't have a complete theory addressing the Life/non-Life border cases and this is why we don't have either proper terminology to address the distinction between a living and non-living entities, nor do we know is the distinction between living and non-living matter a spectrum or clear cut point. The reason too many researchers like to, as I said before, assume it's a spectrum is because that's the risk-aversion scenario for many of them and in such way they can save face if their hypothesis turn out to be incorrect. $\endgroup$ May 28, 2020 at 14:51
  • $\begingroup$ If you are a researcher in the field and you know there is a high chance of being incorrect you would prefer to use blurry terms and "a spectrum" vs a clear-cut line because you put less of your reputation in stake if proven wrong, won't you? But that's secondary, to an extent-anthropomorphic feature which doesn't equate with physical reality. And that reality is that the chances of Life being clearly defined and of being a spectrum of characteristics are just about equal. However, that's too much for most people to stick their necks out and claim they can pinpoint it, that's why you will $\endgroup$ May 28, 2020 at 14:55
  • $\begingroup$ find most people talking about spectra instead of a number of clearly definable traits to distinguish a living organism from non-living entities. And that's something you will very rarely find mentioned in the papers themselves, this is why I felt like I needed to elucidate the point in the comment section. So you may now appearances can be deceiving and there is the possibility people would just prefer to talk this way in order not to make claims they can't prove, even if said claims can turn out to be reality. $\endgroup$ May 28, 2020 at 14:58

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