# What is the advantage of predation?



## JoanDrake (Jul 11, 2013)

What is the advantage of predation in an evolutionary sense? I realize it's a danger and a source or energy which will improve the prey and predator species alike. If, however, there were equivalent dangers and sources of energy available could it be dispensed with? I ask because I'm trying to make a world where predation is nonexistent and there is sentience.


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## Nightspore (Jul 11, 2013)

This is an interesting question. I was always under the impression that humans originally developed/evolved communication because we needed to communicate with each other to hunt effectively. This must have been an incentive to evolve ever more sophisticated & larger brains. Other predatory species, such as cetaceans, seem to have evolved sophisticated communication techniques in order to organise hunting strategies. With humans, probably because of our lack of specialisation, communication became culturally important as well. Again, this was probably linked to biosurvival. Not all primates are predatory though so it would be interesting to ponder on how communication & intelligence would develop in a species that wasn't a hunter.


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## sooC (Jul 11, 2013)

Here's my take: everything that could be food would have to be sentient and willing to sacrifice itself. Like the cow in The Restaurant at the End of the Universe, or pretty much everything non human in Cockaigne.


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## thaddeus6th (Jul 11, 2013)

I believe the predation advantage is that meals can be fewer. Cows spend their lives eating grass, whereas a snake can live for months on one good kill.

A sentient species could opt of predation on moral grounds, I suppose.


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## chrispenycate (Jul 11, 2013)

The trouble is, without predation you'd have to wait for resource depletion to power evolution - you're waiting for the failures to starve to death. Much, much slower than killing the less competent off directly, and I don't see intelligence as giving a major advantage. I suppose a sufficiently hostile, variable environment would serve, although such an environment has brought about some very effective predators on Earth.

But to eliminate predation entirely (at least in multi-cell organisms) we need to eliminate vegetarians, too, and have all lifeforms capable of photosynthesising (though probably with synthetic bacteria to aid in acquiring raw materials. In fact, symbiosis cannot be considered predation, right? So every individual could be a cooperative of different species, and sex gets – complex. Sufficiently so that evolution could actually proceed several times faster (having seen a member of a species that relies on predation (a deer) dying of the overpopulation when natural predators, like wolves, had been eliminated to protect sheep, and a law against hunting had been passed by soft-hearted animal lovers, I don't think starvation a better solution. Certainly not a prettier one)

But the 'how much brain does it take to sneak up on a cabbage?' argument works even more for inanimate materials. What's the survival imperative for intelligence?


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## Nightspore (Jul 11, 2013)

chrispenycate said:


> What's the survival imperative for intelligence?



Communication?


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## chrispenycate (Jul 12, 2013)

And why would something that communicates better have a better survival chance? If it's only a statistical bias it'll take billions of years to make a change. A blackbird's cat alarm call is an immediate improvement in the odds, a bee's pollen and nectar dance helps give its hive an advantage, but would this give us the five or ten percent advantage needed to make the change a selection factor?

Abviously, when you have sapience and symbolic language skills you will have the advantage; it's the intermediate steps that are the difficult to explain.


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## hopewrites (Jul 12, 2013)

The trouble I have with it is the fussy way predation has been made synonyms with consumption in my head. Carnivores prey on Herbivores. Herbivores prey on plants. Some plants prey on each other... it just goes on and one down the line.
So I'd have a hard time buying into a world where there was no predation. Because everything has got to prey on something to survive.


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## Brian G Turner (Jul 12, 2013)

JoanDrake said:


> I'm trying to make a world where predation is nonexistent and there is sentience.



Predation acts at so many levels in nature - there is a whole chain of different organisms that predate on each other. The act provides an important evolutionary stimulus.

Without that, it would be tempting to think of life on such a world as being relatively simple and static. You would be stuck with the lowest rungs of the food chain.


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## Karn Maeshalanadae (Jul 12, 2013)

chrispenycate said:


> What's the survival imperative for intelligence?





Problem solving and learning by example.


Humans, for instance. Without our intelligence, we would have soon been wiped off the face of the Earth by predators. We have naturally soft skin, weaker muscles, less speed, and to be honest, really no fur. We're able to climb trees, sure, but not nearly as well as our less intelligent cousins.

Invention and tool use was a crucial step to human survival. Weaponry, specifically, both to hunt other prey, and to fend off potential predators, such as the larger cats, possibly wolves, bears, and anything else. Intelligence was also a great counter to all the toxins out there. We watch the idiot of the group eat bright red berries off a tree, or those pretty purple bell-shaped flowers? If he kills over, then the more intelligent ones can pretty much tell, "Hey, I think that plant made him die. I had best not eat that."


Just a couple examples there, Chris.


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## Stephen Palmer (Jul 12, 2013)

Nightspore said:


> This is an interesting question. I was always under the impression that humans originally developed/evolved communication because we needed to communicate with each other to hunt effectively.


 
This theory is so out of date it's got a long grey beard!

Here's a few books to read for those interested in this question:

Nick Lane, _Life Ascending_
Richard Leakey et al, _Origins Reconsidered_
Nick Humphrey, _The Inner Eye_

Enjoy!


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## Stephen Palmer (Jul 12, 2013)

hopewrites said:


> The trouble I have with it is the fussy way predation has been made synonyms with consumption in my head. Carnivores prey on Herbivores. Herbivores prey on plants. Some plants prey on each other... it just goes on and one down the line.
> So I'd have a hard time buying into a world where there was no predation. Because everything has got to prey on something to survive.


 
Predation only works in a world where there is oxygen, which is a comparatively recent event (in terms of the total existence of life on Earth). See also Nick Lane _Life Ascending,_ and also his book _Oxygen_.


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## Stephen Palmer (Jul 12, 2013)

chrispenycate said:


> Abviously, when you have sapience and symbolic language skills you will have the advantage; it's the intermediate steps that are the difficult to explain.


 
See Richard Dawkins' _The Blind Watchmaker,_ and also to a lesser extent Lynn Margulis'_ Symbiotic Planet_.


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## Nightspore (Jul 12, 2013)

Stephen Palmer said:


> This theory is so out of date it's got a long grey beard!
> 
> Here's a few books to read for those interested in this question:
> 
> ...



OK thanks. Although it is worth pointing out that communication has to be related to gregarious hunting strategies though. I'm guessing it was one of the incentives to drive dolphins to evolve what appears to be some form of language.


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## chrispenycate (Jul 12, 2013)

not hopeless said:
			
		

> So I'd have a hard time buying into a world where there was no predation. Because everything has got to prey on something to survive.


Yes, in our ecosystem, predation goes back to our earliest unicellular ancestors, and it's hard for us to imagine a system fuelled by anything but selfishness; but 'hard' is what makes us SFF


Karn Maeshalanadae said:


> Problem solving and learning by example.
> 
> 
> Humans, for instance. Without our intelligence, we would have soon been wiped off the face of the Earth by predators. We have naturally soft skin, weaker muscles, less speed, and to be honest, really no fur. We're able to climb trees, sure, but not nearly as well as our less intelligent cousins.
> ...



But all based on a system running parallel to ours, on systematic serial predation. Yes, intelligence in a competitive system becomes useful as soon as conditions can change, which means practically from the start of life. Certainly the ability to react to a stimulus and detect another life form becomes a survival trait before muliticellulirity. But would this be true if you weren't trying to eat it, avoid being eaten by it or mate with it? I can't quite visualise a society based on pure cooperation, symbiosis the norm, no competition, energy eaters as in Gordon Dixon's "Flat Tiger" (Ooops, 1956, I doubt whether many here will know it), kibbutznik organisms green in neither tooth nor claw as neither them nor claws and poisons are required for success.

Would such an ecology ever leave the garden of Eden? Would there be enough pressure to change, if not from competition with other organisms, at least from the environment? I fear not, and foresee an ecology which, though massive has nothing to react to, no reason but friendship with the cell next to it to even attempt multicellular development, let alone sex…


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## JoanDrake (Jul 12, 2013)

Thanks everyone so much, this is great. If I ever get this world made it will be sooo convincing.

And please keep it coming. Again, I thank everyone, appreciate all of your info and your avatar names will be my characters.


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## Nerds_feather (Jul 12, 2013)

JoanDrake said:


> What is the advantage of predation in an evolutionary sense? I realize it's a danger and a source or energy which will improve the prey and predator species alike. If, however, there were equivalent dangers and sources of energy available could it be dispensed with? I ask because I'm trying to make a world where predation is nonexistent and there is sentience.



Population control of herbivores and smaller carnivores, which then produces stability in the ecosystem. If you didn't have predators, you'd have a whole lot of animals breeding and eating all the plant life. 

A solution to this would be to have all the fauna reproduce veerrrrryyyyy slowly.


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## Stephen Palmer (Jul 15, 2013)

Nightspore said:


> OK thanks. Although it is worth pointing out that communication has to be related to gregarious hunting strategies though. I'm guessing it was one of the incentives to drive dolphins to evolve what appears to be some form of language.


 
It doesn't have to be related to that at all. How many noisy, chatty hunters have you seen... not many! Also, doesn't that rather restrict the meaningful content of speech?

Language is social in origin. See also Robin Dunbar's work!


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## mosaix (Jul 16, 2013)

Predation means the top of the food chain benefits from eating practically anything on the planet. We can't eat grass but sheep and cows can and we eat them. It's the same with fish and birds (and in some countries insects). They eat stuff that we wouldn't eat normally and turn it into stuff that we can eat.

Although it doesn't count as 'predation' as such we also use bees to collect nectar and harvest the honey.

And, of course, it's not just food - hide and bone are put to good use.


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## Ursa major (Jul 16, 2013)

So what, before agriculture, we used to have to hunt was... er... game of hide and steak.









I'll get my coat....


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## Gordian Knot (Jul 16, 2013)

JoanDrake said:


> What is the advantage of predation in an evolutionary sense? I realize it's a danger and a source or energy which will improve the prey and predator species alike. If, however, there were equivalent dangers and sources of energy available could it be dispensed with? I ask because I'm trying to make a world where predation is nonexistent and there is sentience.



Hmmmm. Interesting question. The only non-predatory type of life that comes to mind is photosynthesis. Taking in one gas and giving out another. Can something be done along those lines? Suppose humans could eat oxygen as food. Plants release oxygen as a by product of synthesizing carbon dioxide, and of course humans breath O2 and release CO2.

That is an extremely simplified explanation of what photosynthesis does. But the concept is sound. If there is a codependent process where some organisms release what another eats, and visca versca.....

The second half of the problem, what drives evolution. Since predation doesn't, there must be some natural occurring dangers on this world which organisms would have to evolve to escape. Evolution would favor those individuals who had the best chances of evading whatever the danger is.

I'll leave it to you to figure out what those dangers might be. lol.


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## Boneman (Jul 16, 2013)

Seriously weird, but I posted last night and it's gone... evolution? Taken by  a predator?

I have a feeling predation does drive evolution - sharks and alligators and crocodiles and maybe even Elephants (very little difference between mammoths and Elephants) have all had no predators, so no need/impetus to change. Survival of the fittest drives evolution - predators (by and large) take the weak, so the remaining gene pool gets stronger and stronger and the attributes needed to survive adapt along the thousands of years that pass. If you're a mammoth with a shaggy coat and the ice age recedes, and it becomes warmer, you'll shed it pretty quick... 

But I do agree, it's not survival of the fittest, it's survival of the quickest to adapt.


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## Venusian Broon (Jul 17, 2013)

Boneman said:


> I have a feeling predation does drive evolution - sharks and alligators and crocodiles and maybe even Elephants (very little difference between mammoths and Elephants) have all had no predators, so no need/impetus to change.


 
Well they have to respond to changes in their prey - so if their prey becomes 'super-prey', so super in fact that they can't catch them, or they become poisonous etc... - then they die off and become extinct. So their evolution is also driven by the predation dynamic, I suppose. 

Crocodiles however have a very wide range of possible sources of food (just not fussy eaters) so have proved highly successful whatever the environment throws at them. 

For something like sharks - they have adapted to a large number of different niches - some are ocean solitary hunters (blue sharks), others are in packs by shallow seas (Hammer heads I think), some target seals, one filter feeds tiny little things. So sharks have been driven by their diets and what happens to their diets - which again one half of the predation equation. If the prey gets a bit faster and escapes more readily, then the fastest sharks will thrive better. (The most successful shark species, like the crocodiles in a fast changing word, I assume will be the least fussy in their dinner choices.)


Not so sure about elephants as a predator, as they are vegetarians - but they have been prey for thousands and thousands of years, by us (and other related species of humaniods). Possibly also there were super-carnivores in the past hundreds of thousands of years ago that have since died out that preyed on elephants


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## Velocius quam lucem (Jul 17, 2013)

I did some poking around for the definition of sentience, and it turns out there are different concepts of it.
from Dictionary.com:

1.    the state or quality of being sentient; awareness
2.    sense perception not involving intelligence or mental perception; feeling

Then Wiki it (also) says:

Eighteenth century philosophers used the concept to distinguish the ability to think ("reason") from the ability to feel ("sentience"). In modern western philosophy, sentience is the ability to experience sensations.

So, I suppose it depends on what you might call the _degree_ of sentience.

I own the book "Life Ascending" (Nick Lane) suggested by SP, and I recommend it as well as a very good "in depth" course on evolution, predation, and biology. The thing is, most comments so far are based on life on this planet. How do we know that alien life would be anything like us (other than coincidence). We might not even recognize alien life as "life" at all. 

I guess what I'm saying is that yes, it is a good question, and don't be limited by what we already know. After all, I assume this is for a work of fiction???  

I am somewhat intrigued by the discussions on consciousness though, as science does not truly understand how human thought arises out of neural activity.

This guy - Peter Russel - has some interesting things to say about this, but its more along the lines of philosophy:

"The idea that we never experience the physical world directly has  intrigued many philosophers. Most notable was the eighteenth-century  German philosopher Immanual Kant, who drew a clear distinction between  the form appearing in the mind—what he called the_ phenomenon_ (a Greek word meaning "that which appears to be")—and the world that gives rise to this perception, which he called the _noumenon_  (meaning “that which is apprehended"). All we know, Kant insisted, is  the phenomenon. The noumenon, the “thing-in-itself,” remains forever  beyond our knowing." 

- and -

"The tree itself is a physical object, constructed from physical  matter—molecules, atoms, sub-atomic particles. But from what is the  image in the mind constructed? Clearly it is not constructed from  physical matter. A perceptual image is composed of the same "stuff" as  our dreams, thoughts, and feelings, and we would not say that these are  created from physical atoms or molecules. (There might or might not be a  corresponding physical activity in the brain, but what I am concerned  with here is the substance of the image itself.) So what is the mental  substance from which all our experiences are formed?"

I recently watched a science programme where they had found a worm that could impregnate itself - a hermaphrodite worm basically. They even suggested that the worm may not have been aware it was having sex with itself.  

This thread also reminded me of a quote from the book _Life Ascending_ "Quitting smoke drink and sex may not extend one's life, but it might certainly make it seem longer." (Can't remember who it was attributed to.)

Anyway, just some musings of mine.


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## David Evil Overlord (Jul 17, 2013)

Remember a Brian Stableford novel about a planet with no predation. Humans discovered carnivore fossils, and realised something had evolved there which forced life on this planet to be non-violent and co-operative...or die...


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## Boneman (Jul 18, 2013)

Venusian Broon said:


> Not so sure about elephants as a predator, as they are vegetarians - but they have been prey for thousands and thousands of years, by us (and other related species of humaniods). Possibly also there were super-carnivores in the past hundreds of thousands of years ago that have since died out that preyed on elephants


 

Good point: if the vegetation failed, only the fittest would survive the trek hundreds of miles to more food, so the gene pool would improve again. Trust humans to come along and ruin the equation...


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## Stephen Palmer (Jul 19, 2013)

Just to echo Vql that _Life Ascending_ by Nick Lane is a superb book, highly recommended. On a related topic, _Emerald Planet_ by David Beerling is very good too.


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