RE: Quick question about evolution
August 28, 2016 at 3:27 pm
(This post was last modified: August 28, 2016 at 3:37 pm by Yoo.)
(August 28, 2016 at 3:15 pm)Rhythm Wrote:(August 28, 2016 at 3:10 pm)Yoo Wrote: What does a poisonous predator have to gain from very weakly poisoning a prey, like the earliest spiders probably did? Is that really a strong enough pressure for the first incidental venomous spider to have a real advantage?Injury, incapacitation. Hurting or disorienting something is halfway to putting it on the plate, at least. In defense..if your bite just hurts..and mine makes you sick......I'm gonna win that fight.
Yeah I do get the basic reasoning, I just see a few practical issues. Back in evolutionary time when the spiders were just about to become venomous, they probably hunted by ambushing and jumping their prey. (not sure about this, but I think ambushing was there before venom or making a web was.) Now if you've ever seen a spider catch a prey there's not a lot of a fight going on between it and its prey. So that's why I have some doubts about the whole "weakening the prey is a real advantage" claim.
Wow so much replies! Busy answering them...
(August 28, 2016 at 3:17 pm)Stimbo Wrote:(August 28, 2016 at 3:10 pm)Yoo Wrote: What does a poisonous predator have to gain from very weakly poisoning a prey, like the earliest spiders probably did? Is that really a strong enough pressure for the first incidental venomous spider to have a real advantage?
Hunting prey is only one side of the coin. Defending yourself against a larger predator is another. Survival pressure would thus favour higher toxicity of venom.
This is a reply to you and to Aoi Magi.
I don't really get how weakly poisoning a large predator gets you anywhere. As a small scorpion or spider, you're probably eaten before you can even react, and if you're not, you will be before the poison kicks in, right? Remember that the poison was probably not very strong at first.
(August 28, 2016 at 3:18 pm)Gawdzilla Sama Wrote: A strong poison is a "don't fuck with me" system. Mammals and reptiles take note.
Yeah but that only works after the poison is a standard in the spider/scorpion population. There must have been a first poisonous (however weakly) spider, and that one spider couldn't have had any advantage from himself being a warning, because it was most likely eaten anyway. And if it wasn't, an individual can't cause such a system in the mammals and reptiles on its own, so the individual venomous spider doesn't benefit.
Yoo
