How would evolution proceed without predators?

Once again, you’re being an ass, and you’re also wrong according to Richard Dawkins, who says that selection occurs on the level neither of the species nor of the individual, but of the *gene *(the famous “selfish gene”). This has been disputed by some of his colleagues, and some of it may really be a semantic dispute since selection can happen on multiple levels (just like I can say I read “words”, “sentences”, and “paragraphs” even though I’m really just parsing a sequence of letters).

The idea that predators get 100% of animal biomass while scavengers only get 1% is…well, I’ll try not to put it the way you would so I’ll just say that I think I can fairly convincingly dispute that. A healthy bull elephant has nothing to fear from predators, but it can be eaten by scavengers when it dies. Same is true really of many healthy adult animals: it is the young, the old, the injured, and the weak who get targeted most of the time.

Plus, if predators could get 100% now instead of waiting for 1% per year or whatever you’re postulating there (your numbers don’t seem to me to add up), they’d eat all the prey animals today, burp, and then get hungry again, start having to turn on each other, and before long all animals would be extinct.

I’m not going to address your extensive claims about “micro-managing”, which I think fail to be persuasive; but will say that it does all make me wonder if you are a Ron Paul enthusiast. :eek:

Nope, that’s not what I’m postulating. There’s plenty of solar energy up on top of Everest. It’s just more trouble than it’s worth, unless it became the case that everywhere else was even less hospitable.

On my Everest supposition:

I think it is likely to be valid even for other forms of life, but it’s probably easiest to use humans as an example. Just as people will climb to the top of trees to evade a flood, or hang out of windows to get air when there’s a fire inside and choking black smoke, I think we can all agree that if it became true that the peak of Everest was the most, rather than one of the least, hospitable environments left on Earth, humans would relocate there, assuming we had at least some time to prepare (that is, adapt). Right? We’d put domes or bunkers up there, use greenhouses to grow food, etc. Whatever it would take.

Presumably you don’t believe humans are separate and distinct from other life forms? If you do, then we really just can’t even engage on any shared set of definitions (it’s already looking tenuous on that front). IMO, homo sapiens is just another life form that adapts as best it can to changes in its environment, in order to survive, consume resources, and reproduce.

What?!? You get so nitpicky as to complain that I didn’t actually use the word “murder”, but you managed to extract this straw man from my posts? Please, tell me what in any of my posts you are paraphrasing here, because I don’t recognise it whatsoever.

Indeed it wouldn’t. But it would be easier than everywhere else–that was the premise! I won’t disparage your ability to “read for comprehension”, but I’d suggest reading that post again because I think you missed my point entirely.

I never said there would be more area at the top of Everest than there is now. Not sure where you got that. I said everywhere else progressively became more inhospitable than Everest is, while Everest stayed the same. Same in conditions as it is now, same in size as it is now. More biomass than it has now, simply because the conditions are (in my thought experiment scenario) worse everywhere else than they are on Everest and so ecosystems would get “pushed” to the top of Everest out of “desperation” (in quotes again because evolution and natural selection do not actually feel emotions or have purpose other than replication, but can be characterised as having pseudo-intention or pseudo-motivation).

ETA: Blake, notice that FixMyIgnorance takes a similar position as your basic one, but is more pithy, more persuasive, and less jerky. Might be an opportunity for a learning moment.

You’re out of line for Great Debates, SlackerInc. Whatever you may think of anybody else’s debating style, you’re absolutely not allowed to insult them as posters. Don’t do this again.

Wow, I’m really surprised that if you read the exchange you think I’m the one out of line! Huh.

Here’s a tip: That’s Blake’s style - if there is some valuable info in the post, great, otherwise, try to ignore the style in general.
Blake has some good points but it doesn’t mean you can’t still get closer to where you want, this is where I think you need to take this:
Consider an isolated environment that doesn’t initially have predation. Not sure but do all types of bacteria feed on each other? If not, setup a little isolated experiment, you’ve got a window prior to predation to keep them isolated and see which way things get pushed.

Ok, well that just makes plain sense. I think the intent of the OP was to imagine the improbable situation where there was no predation at some time, and some kind of natural force preventing it, and then what kind of evolution would evolve before that natural force fell to evolutionary adaptation. But as I tried to state initially, there’s still the competition for food, and the most efficient will win that. But as you point out, eating other animals can be very efficient and eventually evolution would win out given sufficient time. So yes, one of the results of the initial scenario is that predation would arise once again.

  1. Certain types of fungus went that direction but ultimately failed and went extinct, when the surviving animals became too fast.
  2. Certain types of plants went that direction but ultimately failed and went extinct, when the surviving animals became too strong
  3. If the animals aren’t mobile they would be susceptible to predation by plants and fungi.
  4. Because as I said above, it takes two stages to make the toxin safe. The second stage is in the roots of the plants.
  5. It evolved in the reefs between sponges. It was a huge arms race between predatory sponges resulting in the toxin. All known life on the planet evolved from those sponges.

See, it’s almost like we are answering the question. Now, if someone asks you “How would evolution proceed without predators” instead of a wall of text, you can say “well in my expert opinion I believe that the resulting animals would need to be too fast to be preyed upon by fungi, and too strong to be preyed upon by plants.”

Thanks, I appreciate the tip. I guess too that now I know it’s okay for me to just return fire in the same manner but not okay to call them out for their rudeness. Not the type of moderation I’m used to but I’ll adjust.

How would evolution proceed without predators? Dodos. The world is full of nothing but dodos.

Actually, there was the Haast’s Eagle. I’m not sure if it’s known that they predated on the kiwi specifically, but I’m sure they wouldn’t have turned down a little furry snack. Kiwi are nocturnal (probably as a way to avoid predation).

Earthquakes help.

Been done. For 50% of earths history there was only blue-green algae that fed directly on minerals. No evolution, extremely persistent and boring. For another 25% they were still around, but something began to nibble on them.

I think the rate of evolution is related to the amount of biodiversity. Higher species density means more chances one will evolve into an empty niche. So, I can envision two end states. In a species-rich environment, predation would likely re-emerge. In the species-poor environment that we are creating, one might just get a progressive die-out with just a few aquatic and terrestrial plant forms and a few browsers left.

Differently.