Stop the fish ignorance

In order to be acknowledged as a biologist, you have to have a working knowledge of biology. All vertebrates have a central nervous system, by definition! It's inside the spinal cord. This was covered in second-year high school biology back in my day. Perhaps in this anti-science pro-religion era the course has been postponed to the university level, but anyone who does not know that fish have a central nervous system is not a biologist.

As to whether fish have emotions... Emotions require some fairly complicated chemical and electrical signal processing so it's safe to say that worms and amoeba with their primitive, decentralized nervous "systems" can't possibly have them. I'm not qualified to hypothesize about more complex creatures like the octopus, but any animal with a central nervous system and a forebrain has enough synapses to be a candidate. Any proper vertebrate, or probably even the sharks, eels and other cartilaginous quasi-fish off in their own phylum.

I haven't seen any scholarly assertion by a biologist to the effect that some minimal level of synaptic complexity has been identified beneath which emotions are impossible in the lower vertebrates. So emotional capability is a spectrum. It stands to reason that the animals with smaller, simpler forebrains--the fish, amphibians and reptiles whose exothermic metabolism has to make do with a very parsimonious ration of fuel and oxygen to burn it--have less emotional range than birds and mammals.

The dividing line between an emotion and an instinct is blurry. If an animal acts companionable toward a human, is it the emotions of friendship and gratitude, or is it the pack-social instinct?

Those of you who think you've seen emotion in a fish's face--a dead fish no less--need to understand that humans can express our emotions to our pack-mates with something like 100 muscles that do nothing but move around the skin in our faces for the specific purpose of communicating non-verbally. Even dogs, our oldest companions in civilization, have nothing like that; they can't furrow their brows or purse their lips. How many facial muscles do you suppose a fish has? If a fish is capable of feeling fright or sadness as an emotion rather than an instinct, does it actually have the muscles to express it? Why would it? What is the survival benefit?

Birds are far more advanced anatomically than fish, and the only part of their face they can move with muscles is their eyelids--a body part fish don't even have! They can also fluff their feathers for warmth, and they use that single small motion to express the entire gamut of negative emotions from fear to loathing--but only as a minor supplement to their well-developed vocal abilities.

Surely fish feel pain, but the question is: how much? Every species has a different pain threshold. Dogs are remarkably blase about blows, punctures and pinches to many parts of their bodies. It's a function of the density of nerve endings in that region of the skin, as well as the synaptic programming to interpret the sensations. How many nerve endings does a fish have in its mouth, with which to sense the hook? I'm sure if we ask enough ichthyologists that question, one of them will know, but I doubt that he's here with us since SciForums is pretty low these days on representatives of some of the hard sciences.

Anthropomorphism: don't let it get in the way of science. There are plenty of good reasons to be kind to animals.

 

Well... That's not 100% accurate. It's true that the grain-based diet that supported most of humanity from the dawn of civilization until quite recently is so poor in nutritional quality that it reduced adult life expectancy from the 40s in the Mesolithic era to the 20s in the Roman Empire. But we have finally learned to create a balanced diet without animal flesh if we so choose. The real issue is that we spent six million years evolving off in a different direction from all the other primates, and became predatory carnivores. We have the instinct to eat meat.

However... As I have pointed out before, what distinguishes Homo sapiens from all other animals is our uniquely massive forebrain. We have the ability to override our instincts with learned and reasoned behavior. To a qualitatively greater extent than our companion animals, we can do things that contradict our instincts, teach them to our children, and build an entire civilization on them.

The first of these learned and reasoned behaviors was to override our gorilla-chimpanzee pack-social instinct and learn to live in harmony and cooperation with total strangers. This allowed us to build civilization in the first place and was thus a very good precedent.

If we can do that, we can learn and reason our way to not being carnivores any more. The question is why? What will motivate us to do that?

I won't eat dog, horse or rabbit meat because I regard them as part of our community. I won't eat whale or monkey meat because they're so intelligent I'd rather try to communicate with them. I eat pork only because I'm good at cognitive dissonance: pigs are highly intelligent and people have begun keeping them as pets and I just don't even think about it while I'm shopping and cooking. If I had children they would probably see through me and convince me to stop eating it. Will each generation find excuses to consider the meat of a few more species taboo, until they're all exempt?

Or will most of us always feel comfortable eating the most primitive animals like shrimp and snails?