Organisms with "protection": contradiction to evolution?

[gohanick]

Ok, so there are some creatures in the world that have spikes on them or a poisonous slime that keep predators away. How did these natural protections form in the evolutionary prospective? Wouldn't a speicies die without the protection before it could gain a trait like this?

 

Also, lets take strawberries as an example for my next point. This fruit has no natural protection, yet it is constantly eaten by its "predators". Why has this fruit, or any other common ones, not formed protection to keep it safe?

[ydoaPs]

Ok, so there are some creatures in the world that have spikes on them or a poisonous slime that keep predators away. How did these natural protections form in the evolutionary prospective? Wouldn't a speicies die without the protection before it could gain a trait like this?

spikes have little harm to their owners. as for poison, the poisons that killed the poison bearer would not be passed on because such organisms that poisoned themselves would rarely live to reproduce.

 

Also, lets take strawberries as an example for my next point. This fruit has no natural protection, yet it is constantly eaten by its "predators". Why has this fruit, or any other common ones, not formed protection to keep it safe?

being eaten is an advantage for the fruit. it disperses the seed. it actually helps the plant reproduce.

 

check out this site.

[ydoaPs]

check out these threads, too:

http://www.scienceforums.net/forums/showthread.php?t=13261

http://www.scienceforums.net/forums/showthread.php?t=9484

[Cap'n Refsmmat]

A species wouldn't necessarily die without spikes or protection. It would just have a harder time of things, and then suddenly, it has self defense, and everything's a lot easier.

[NeonBlack]

Pineapples do have "protection"

The outside is all pokey and shit. And if you eat too much fresh pineapple, it makes your mouth hurt like a mother.

[swansont]

Ok' date=' so there are some creatures in the world that have spikes on them or a poisonous slime that keep predators away. How did these natural protections form in the evolutionary prospective? Wouldn't a speicies die without the protection before it could gain a trait like this?

[/quote']

 

No, not all of a population would necessarily get taken out by predators, even if they don't have the protection you describe. And it would likely have some other trait or "strategy" before the new trait evolved (e.g. fish that lay a lot of eggs; even though the newborn fish are relatively defenseless, some survive just because of the sheer numbers of them. The predators simply can't eat them all.) And, of course, most species do become extinct.

[Radical Edward]

Ok' date=' so there are some creatures in the world that have spikes on them or a poisonous slime that keep predators away. How did these natural protections form in the evolutionary prospective? Wouldn't a speicies die without the protection before it could gain a trait like this?

[/quote']

no. The predators aren't going to eat all individuals in a population, only some of them. those that have the features that make them less likely to be eaten will see their genes spread through the gene pool, increasing the numbers of individuals in subsequent generations with those features.

Also, lets take strawberries as an example for my next point. This fruit has no natural protection, yet it is constantly eaten by its "predators". Why has this fruit, or any other common ones, not formed protection to keep it safe?

 

because the point of strawberries is to be eaten. the seeds do not digest easily when eaten by herbivores and birds, and when they emerge into the world, they come neatly packaged in fertilizer.

[jeskill]

You are assuming that the predator was in it's current form and was eating the prey before the prey evolved protection. That may not necessarily be the case.

 

Sometimes, prey-predator relations co-evolve, kind of like an arm's race. Check out here: