Thread: Did life feed on other life from the beginning?

Hey, sorry if this is a stupid question. But I was thinking about abiogenesis again...

If life first started by feeding on inorganic sources (Light, water etc) and flourished. Was life feeding on other life required to develop more complex forms of life?

Animals, insects and humans need inorganic sources and organic sources both (Food, sun) but it feels strange that "higher" lifeforms that develop - is 100% dependant on "lesser life".

This would seem like a safety net for basic lifeforms like plants, not to get extinct from "Death by its children" (Higher devloped life like humans) so to speak... due to dependancy and synergy. Almost as if life in itself is a "body", just as the cells in our bodies provide survival - and killing them off would be counter-productive like cutting out your own heart.

Yes I know evolution doesent have a mind or conciousness! But I'm curious as to how early organic life started "feeding on itself" and if this was needed to develop further?

Ok rambling done

No.
The earliest 'life' probably consisted of polymers inside fatty acid vesicles, which would accept new material dissolved in the surrounding water. The first such 'nutrients' would be non biotic in nature - generated by chemical reactions using lightning, ultraviolet or other energy source, in an atmosphere of nitrogen, ammonia, CO2 etc.

Even today, there are bacteria that survive very nicely using chemicals produced by non organic sources.

Well. yes, on the last question. Life feeding on life was necessary for the evolution drive. Without predators, there would not be any need for evolution. The first predators would actually be feeding partly on it's own species. So they could split in several types. Some "chose" the defend path, develloped camouflage, or a shell. Others "chose" the attack path, so they develloped teeth, venom and speed.

I'm well aware the term chose is not right. They were selected, driven apart. They followed the path of least resistance, based on chance and enviroment.

Play spore, and you learn the need to develop.

Originally Posted by Zwolver

Well. yes, on the last question. Life feeding on life was necessary for the evolution drive. Without predators, there would not be any need for evolution.

Zwolver, I thought you said you were a biologist. Your comment here makes me doubt it.

Firstly, you are back to a teloeogical bent with your talk of need. Evolution does not occur because it is needed, it occurs because that is a natural consequence of how life systems operate.

Secondly, of course evolution can and does exist without predators. Selection will favour any organism that is genetically better at:
1) Detecting food sources
2) Handling a wider variety of food sources, or concentrating on a specific nich food source
3) Reproducing
4) Handling ambient conditions
5) etc.

Yes, maybe "need" was not the best word to put it. I was mainly pointing out, that a predatory system is one of the, or the most important evolutionary drive.

on your second comment
1) Detecting food scources, the more food you can get, the faster you grow, and the bigger you are, the less chance a predator catches you.
2) More food scources, faster growth, less time possible for a predator to catch you.
3) Reproduction... more targets, less chance for you to be food..
4) Ambient conditions, may be restricted to a night, or a day time, this is so because of the predators. Also living in environments where predators can not, helps as well.

If you use examples to disprove the thing i just said, use correct ones. All those you said were connected to the predatory system. Only extreme harsh survivalists are unaffected by the predatory system. Like lunar microbes, martian worms (if they exist), heat spring bacteria (except the thermal vent ones) etc.

I answer these topics without actual researching the topic, without using to much spellcheck, or exact knowledge about the topic. I just answer these things for fun, because i want to put my mind off work, and it helps me concentrate.

Originally Posted by Zwolver

Yes, maybe "need" was not the best word to put it. I was mainly pointing out, that a predatory system is one of the, or the most important evolutionary drive.

No, that is not what you said. You said categorically that evolution would not occur withour predators. That is completely incorrect.

Originally Posted by Zwolver

If you use examples to disprove the thing i just said, use correct ones.

All my examples were valid ones. You are twisting meaning to try to tie each of them back to predation. You seem to think life is composed primarily of multicellular eukaryotes and vertebrates at that!

Let's take a closer look at your spurious attempt to manipulate meaning.

1) Acquiring better food sources may help you better avoid predation, but it also improves your chances of surviving adverse environmental conditions; it improves your chances of finding a mate; it improves your chances of supporting your offspring, if you are instinctually inclined to do so; etc. You have zeroed in on a single aspect - avoidance of predation - as if it were the only aspect. In some cases it is not even relevant - explain how acquiring a root system that can penetrate deeper allows a tree to avoid predation.

2) A wider variety of food sources is primarily important because it allows an organism to survive in extreme environmental conditions because thre is a higher probablility that it will find a compatiable food source. Predation is all but irrelevant in this instance.

3) You seem to think that better at reproducing means more offspring. That is not necessarily the case, which is precisely why I simply listed reproduction. Some organisms favour the 'more the merrrier' approach, like turtles, laying scores of eggs in the hope that one or two will survive to adulthood. Others rely upon extended care and attention like elephants. In either case the 'objective' is to survive the vissicitudes of the environment, which may include, but is certainly not limited to, predation.

4) Pretty much as above.

I answer these topics without actual researching the topic, without using to much spellcheck, or exact knowledge about the topic. I just answer these things for fun, because i want to put my mind off work, and it helps me concentrate.

So don't take offence when it is pointed out that you are wrong. When someone identifies themselves as a biologist one expects that they will post accurate information relating to biology. If you intend to post without an exact knowledge of the topic, or without actual research then at least tell your audience that you are expressing an opinion. Deal?

I agree, as i'm always expressing opinions. Most people only express opinions, as facts are rare. Though, you haven't really contradicted me. You are still implying just like i said that predators are a huge impact on evolution. As my opinion is that shaving off rough edges (with predators) not only keeps disease to a minimum. It also limits a species on subjects like, speed, defence, camouflage (yes pokemon abilities), as speed WAY to much as your prey is useless, and so further speed is not promoted. Having more venom then necessary is also useless (quantities). I know for a fact that you will disagree to this, and continue mocking me, but it's okay. I forgive you .

Zwolver, I am not denying the important role that predators can play in evolution. However, I notice two things from your last post:

1) You still fail to acknowledge that your initial statement was completely, utterly, irrevocably, deeply and fundamentally wrong. I remind you of that statement - " Without predators, there would not be any need for evolution." When I make an error I acknowledge it, directly, simply and immediately. It does not happen very often because I have sufficient respect for the forum and its members that I check my facts before I post them. Which brings me to the second point.
2) "Most people only express opinions, as facts are rare." Your words. All of the better posters post many facts and when they post opinions they make it clear that they are opinions. Had you said, "in my view without predators evolution would not occur" then we could have discussed your opinion. Offered as it was as a fact the only course open was to vigorously deny it.

You seem to think I am mocking you. I'm not sure if you are serious in that claim or not. Well, I am not mocking you. I am correcting inaccurate statements you are making about biology - corrections that should be unecessary.

Originally Posted by Zwolver

I agree, as i'm always expressing opinions. Most people only express opinions, as facts are rare. Though, you haven't really contradicted me. You are still implying just like i said that predators are a huge impact on evolution. As my opinion is that shaving off rough edges (with predators) not only keeps disease to a minimum. It also limits a species on subjects like, speed, defence, camouflage (yes pokemon abilities), as speed WAY to much as your prey is useless, and so further speed is not promoted. Having more venom then necessary is also useless (quantities). I know for a fact that you will disagree to this, and continue mocking me, but it's okay. I forgive you .

You have made an error by stating incorrect facts as true, while claiming to be a biologist. Why not simply acknowledge your mistake and move on? Why this contorted attempt to twist yourself into the right when it is obvious you were simply mistaken? There is no shame in being wrong once in a while. What you do when your mistakes are pointed out is what matters. It would do you and us all good to, as John suggests, you clearly state when and if you are providing an opinion or not. This is not simply a general chat forum. We all come here to converse about science and appreciate accurate information. I am confident that you can be a good source of that.

Thanks in advance

You are affected/influenced by the environment, but you are also part of it. There's is a dynamic interaction between the various aspects of the environment that we happen to arbitrarily distinguish/conceptualize from our perspective.

Complex life* (*which is a label) does not "need" or require to feed on other life, life feeds on the environment and it is itself also part of the environment.

So imo, molecules assembled by life being a part of the environment make it likely in practice that complex lifeforms will use these instead of starting from scratch, but in theory its not required or needed.

Yes i know i made an error in stating that. I said i did. But in this case, there is little proof how evolution was driven. As i have not found very much proof, just theories, statements and observations.

Greatest Mysteries: What Drives Evolution? | LiveScience

There is no actual data, things that can be directly tested. As i don't know how i can find this data on the DNA of... lets say a jellyfish.

Where would i look?

Do i look at fylogenetic trees? Or do i look at the prey/predator's DNA and compare this. Or is there a returning loop, the ultimate DNA strand that seems to be forming?

Anyway, i try to be true in my claims. So let me rephrase this. What i meant to say was, i think predators played a huge part in the natural selection and have driven evolution for a big part.

The statement i said that without predators there would be no need for evolution, should have put differently as well. I was actually thinking reversed, as reverse thinking solves some problems many people don't come up with (easily), i pressed submit on that, while i should have read it again if it made sense. So what i should have said was, if evolution was concious, a process of choice, then without predators, prey would have no reason to evolve.

I tried to point out mistakes in your thinking as well (not that it was false, but just incomplete), but as english as my third language, it's not that simple. And i tend to scurry on to do some actual work, so i submit what i have at that time.

And again, i'm sorry for being stupid..

Great, thanks for that! Not too bad for English as a third language.

without predators, prey would have no reason to evolve

Why do you breathe oxygen? Its as vital as anything, without it you die much sooner than starvation or predatory threats.
Have predators 'driven' the oxygen breathing evolution of our extremely ancient ancestors that started using it?
I think adaptation to the environment and symbiotic relationships might be more related to this evolutionary result than pure predation.

Also humans continue to evolve even if we have no significant predators, there's a great many variations and changes that are not visible to the naked eye.

Predation is an important factor, but not the only one. Chernobyl mice might be more resistant to radiation than jaguars in tropical forests, without predators having a primary role in this situation.

I would like to point out to the debaters in this thread that the OP related to earliest life. When you talk of predators and mates, etc., you are not talking of the earliest life.

If we want a thread of what drives the evolution of higher life forms, that is a separate topic requiring a separate thread.

Originally Posted by skeptic

No.
The earliest 'life' probably consisted of polymers inside fatty acid vesicles, which would accept new material dissolved in the surrounding water. The first such 'nutrients' would be non biotic in nature - generated by chemical reactions using lightning, ultraviolet or other energy source, in an atmosphere of nitrogen, ammonia, CO2 etc.

Even today, there are bacteria that survive very nicely using chemicals produced by non organic sources.

Also, wasn't the moon much closer to earth creating a washing machine effect on the earth producing a higher ratio of energy that could be used readily by bacteria? Wasn't the earth being hit often by comets and other things from space, also providing more energy sources?

Originally Posted by icewendigo

You are affected/influenced by the environment, but you are also part of it. There's is a dynamic interaction between the various aspects of the environment that we happen to arbitrarily distinguish/conceptualize from our perspective.

Complex life* (*which is a label) does not "need" or require to feed on other life, life feeds on the environment and it is itself also part of the environment.

So imo, molecules assembled by life being a part of the environment make it likely in practice that complex lifeforms will use these instead of starting from scratch, but in theory its not required or needed.

So it is kinda wrong thinking of inorganic or organic life seperate. One should rather think of them all as more available resources in the melting pot?

I just cant stop thinking of how perfectly life is due to "cannibalization" if this is the case - for the greater good. Sure life assimilates life. But in turn that higher lifeform (Humans) could use their best traits like intelligence - to stop a meteor hitting earth with nukes. Thus this cannibalization pays off by the new forms of life to also protect simpler life.

For the record I have no knowledge of biology but the synergy life provides itself in making all life stronger overall facinates me :P

As sceptic pointed out though, I am most interested in the earliest stages of life. You guys think predation/canniballizing was a absolutely needed for life like humans to develop further down? That is my main question.

Earliest life would have comsumed organic chemicals generated by non living chemical processes.