Are vertebrates really more intelligent than other animals?

[viper69]

Look as the swarms of lampreys in rivers. Look at all the lizards on the trees. Is there really anything to suggest that the average vertebrate is anymore intelligent than the average mollusk or arthropod?

Seeing as you are speaking generally, all things being equal, the answer to your question is YES.

 

[The Snark]

I think I see the point there. Vertebrates have their own subphylum while invertebrates are everything that isn't vertebrata.

 

[schmiggle]

Invertebrates are a taxonomically stupid group, as snark said. A tunicate is more like a fish than it is like a fly, but they're still both grouped as invertebrates. While it is true that vertebrates have characteristics not found in any other group, this is no more true of vertebrates than of, say, nemertean worms.

 

[CladeArthropoda]

Define group?

No such thing as invertebrates? That's simply not true, scientists use the terms invertebrate and vertebrate regularly.

A clade is an ancestor and all it's descendants. Vertebrates fit this. Invertebrates do not.

http://www.bioinfo.de/isb/2007070015/fig1_highres.jpg
Look at this. It isn't completely spot on, but it's fairly accurate with the data we have now. Noticed how vertebrates are one branch on the vast tree of animals. Vertebrates are a real group with many synaphomorphies. "Invertebrates" are just any animal that's not a vertebrate. It's like dividing animals into mollusks and "unmollusks". Mollusks have a radula. Unmollusks do not have a radula. You see how stupid that is? A mosquito is closer to you than it is to a stone coral. This is why "invertebrate" is a meaningless term.

 

[The Snark]

Getting a little lost in nomenclature I think. Just change in to non. Not a vertebrate.

 

[Anoplogaster]

Ok, I'll bite this bait with my brief viewpoint:

"Pain" is a term with a flexible definition. If an organism reacts negatively to harmful stimuli to avoid harm, is that organism experiencing pain?

You are right, invertebrates are not a proper taxonomic designation. But it's still used widely. One could argue that the invertebrate condition is symplesiomorphic, almost like using the term "Agnatha" to refer to your lampreys. Just because it isn't a taxonomic designation doesn't mean you can't use the term.

 

[The Snark]

Let's complicate the issue. Depending upon which study is referred to, umyelinated nerve endings have been grouped together as pain receptors. Their presence, or lack thereof, has been the determining factor in many studies to ascertain whether or not an organism is capable of feeling pain. However, this is considered a gross over simplification by many researchers.

 

[schmiggle]

"Pain" is a term with a flexible definition. If an organism reacts negatively to harmful stimuli to avoid harm, is that organism experiencing pain?

Not necessarily. There needs to be some kind of "emotional" component--there has to be a part of the brain that can process unpleasantness, rather than immediate stimulus avoidance. But sure, part of the problem is that you can't actually feel like an earthworm, say.

 

[Anoplogaster]

Not necessarily. There needs to be some kind of "emotional" component--there has to be a part of the brain that can process unpleasantness, rather than immediate stimulus avoidance. But sure, part of the problem is that you can't actually feel like an earthworm, say.

Now, define "emotion." Is fear an emotion? Could one argue that an organism actively avoiding danger is experiencing fear? If I poke a trochus snail, it crawls away actively.

 

[CladeArthropoda]

Ok, I'll bite this bait with my brief viewpoint:

"Pain" is a term with a flexible definition. If an organism reacts negatively to harmful stimuli to avoid harm, is that organism experiencing pain?

You are right, invertebrates are not a proper taxonomic designation. But it's still used widely. One could argue that the invertebrate condition is symplesiomorphic, almost like using the term "Agnatha" to refer to your lampreys. Just because it isn't a taxonomic designation doesn't mean you can't use the term.

Well, that's different. All "agnathans", while not a true group, share many aspects about their biology and life style. Same for "reptiles". But the same can not be said for "invertebrates". Even under a purely superficial way of looking at things, invertebrates fall flat. Crocodiles are not directly related to lizards, but they are pretty similar in many ways. What does a snail and insects have in this way?

 

[schmiggle]

Now, define "emotion." Is fear an emotion? Could one argue that an organism actively avoiding danger is experiencing fear? If I poke a trochus snail, it crawls away actively.

You lumped together three different things this time. First of all, if the snail has a direct stimulus response--poking automatically leads to crawling the other way, without going through an internal processor that could decide not to--then there's clearly no pain, or unpleasantness of any sort. Then, even if it is feeling fear, when I said emotion, I didn't mean any old emotion. If the snail felt happy when you touched it and then decided to walk away because of an ascetic principle it had, I would say it was feeling an emotion but not pain, and I would usually say the same thing about fear. Pain is specific: it is an unpleasant feeling associated with damage. For the snail to feel pain, it would need to have a set of neurons that felt the damage, decided it was unpleasant, and took action to try to avoid further unpleasantness.

 

[Anoplogaster]

You lumped together three different things this time. First of all, if the snail has a direct stimulus response--poking automatically leads to crawling the other way, without going through an internal processor that could decide not to--then there's clearly no pain, or unpleasantness of any sort. Then, even if it is feeling fear, when I said emotion, I didn't mean any old emotion. If the snail felt happy when you touched it and then decided to walk away because of an ascetic principle it had, I would say it was feeling an emotion but not pain, and I would usually say the same thing about fear. Pain is specific: it is an unpleasant feeling associated with damage. For the snail to feel pain, it would need to have a set of neurons that felt the damage, decided it was unpleasant, and took action to try to avoid further unpleasantness.

If I put my hand on a hot stove, there is no decision-making regarding its unpleasantness. It is simply a reaction. Now, there is also emotion tied to the memory of an unpleasant experience, which requires complex processing. But the experience of pain, itself, is nerve response.

 

[Anoplogaster]

Well, that's different. All "agnathans", while not a true group, share many aspects about their biology and life style. Same for "reptiles". But the same can not be said for "invertebrates". Even under a purely superficial way of looking at things, invertebrates fall flat. Crocodiles are not directly related to lizards, but they are pretty similar in many ways. What does a snail and insects have in this way?

Snails and insects lack vertebrae, making them similar

 

[CladeArthropoda]

Snails and insects lack vertebrae, making them similar

"Humans and mosquitoes lack a radula, making them similar"

 

[schmiggle]

If I put my hand on a hot stove, there is no decision-making regarding its unpleasantness. It is simply a reaction. Now, there is also emotion tied to the memory of an unpleasant experience, which requires complex processing. But the experience of pain, itself, is nerve response.

You're absolutely right--pain is actually not really causing the hot stove reaction. That's a perfect example of the sort of thing that doesn't count, at least to my mind. There's a direct input-output: nerves tell spinal chord stove is too hot, spinal chord automatically jerks hand backwards. The pain actually comes later, when your hand, still damaged, tells your brain to accommodate the damage (mainly, treat it tenderly until it heals and do other things to make it hurt less). It's this latter stuff that actually counts as pain.

 

[Anoplogaster]

"Humans and mosquitoes lack a radula, making them similar"

Correct We ARE similar in that way, because we are both not mollusks!

 

[schmiggle]

Though by cladistic reasoning humans are more like tunicates than wasps, wasps recongize faces in similar ways to humans and are similarly cooperative. Similar reasoning holds for octopuses, which, though cladistically different from humans, are similarly curious and intelligent, being able to manipulate their environment to solve puzzles. All of which is to say that there are multiple definitions of similarity, of which the cladistic one need not be the best.