A recent article in Discovery News reports that lobsters and crabs feel pain. While this has been suspected for quite a while, due to the primitive nature of their nervous system, it has been challenging to quantify or qualify what their sense of the pain would be. Recent research at Queen’s School of Biological Science, published in the Journal of Experimental Biology, under the title, “Painful Feelings in Crabs,” tested crabs and showed that when shocked at a specific desirable location, soon they modified their behavior to avoid that location. The Discovery article notes similar results for lobsters.
All animals have some form of feedback system to help them survive by avoiding negative stimulation. In looking at the biology of a crab, for instance, their primitive nervous system is indiscrete and sparse. As for many other animals, likely, a crab sense pain but does so differently from animals with a highly discrete nervous system like humans. A negative stimulation at the tip of their claw would most likely register as a dull ache throughout their full arm and claw for a crab. It is also possible that it is even less localized than that. Unless we can find someone who has a regressive memory of their past life as a crab—I mean the horizontal eight-legged version, not the vertical two-legged version, we really will never know.
For us, it would be like a small prick to the finger, making our entire arm have a dull pain instead of the sharp prick we actually sense. All feelings are not alike, even in our own bodies. Our own sense of pain is tied to the number and type of nerves and receptors that we have in any location.
You can try this experiment at home if you want. Close your eyes, and have a trusted friend, or calm and sedate spouse, take a pair of scissors, and very lightly, I said very lightly now, press the tips of the scissors to your fingertip. Have your partner start with the scissors closed and then gradually open them wider and wider until you, with your eyes remaining closed, feel two points, not one—use a ruler to measure the width point to point. Now do the same thing, only, this time, use the middle of your back (not directly over a bone-like that of your spine). Again measure the distance point to point. You will find that you can discern the tips quickly, almost immediately, at your fingertip, and remarkable wider on your back. This is because you have lots of discrete and specialized nerves and pain receptors in your fingertips, evolved to help you protect these vital tools of your survival and very few in your back. Little known is that all living things have negative stimulus avoidance detection systems, even plants.
Several years ago, I jokingly told a vegan friend that while I did eat meat, at least when I ate a steak, the animal was dead, unlike the fresh plant that she was enthusiastically crushing with her molars. She replied that plants did not feel pain. In response, we walked outside, and I pinched the leaf of a mimosa treat; she watched in what soon became mild horror as the rest of the leaves slowly closed upon the affiliated branches. My joke ended up not being so funny to her. She replied, with much more emotion than I expected, “What am I supposed to do now? I don’t want to harm any living things just to eat!”
It is not just mimosas that have a much more responsive system than most plants. All plants respond to negative stimuli. If you place a plant near a dangerous heat source, it will either twist away slowly or always grow from the negative source. It appears their system is more of a chemical response system than the electrochemical and biologically observable structural system that we can see in most animals. Yet, it is nonetheless in place and observable if you want to see it. Indeed, plants don’t have a brain. But it is clear that the lack of “brain” does not stop a plant from responding.
You can say it comes down to what pain is in the first place! Today, we live in climate-controlled houses, buy food from the grocery store, or have it delivered from an online purchasing system. We drink filtered and processed water. We have a host of biochemical weapons to keep other predatory species at bay.
We have evolved whole cultural groups that believe that we should not kill or harm other species for one reason or another. Interestingly, our ancestors would have agreed with that statement with the addition of one word—needlessly. Historically few humans have needlessly slaughtered animals. In fact, most primitive cultures developed rituals revolving around the harvesting of animals and plants for survival. Most cultures abhorred needless slaughter as it was understood that it impeded their survival to wantonly destroy and make unavailable their own food! Humans have evolved to become omnivores; we can eat just about anything, living or dead, with some exceptions. This adaptation, in conjunction with our big brain, is what, for the time being, has put us on the top of the food chain.
Initially, it was our ability to hunt and gather that gave us an edge. We killed for necessity, not for sport. Perhaps it was because it took so much time to hunt, kill, gather and process our food supply; we simply were too tired. Or perhaps, like people do today, few turn their livelihood into their recreation as at the end of a productive day we really all want to get away from that activity and do something different. Over time we began to domesticate animals, and instead of gathering our food, we grew it. As we domesticated the animals and plants that we used as food, we also humanized our relationships with those species in some respect. No longer hunting for survival, hunting became a pastime. For many who no longer have to grow their food, gardening also became a pastime. Some say we have an evolutionary predisposition to do these activities. Today, we have de-evolved, some say evolved, to look on our prior food sources as co-equal for survival.
An interesting development that speaks volumes about our disconnection from the forces of natural selection. Today, it is fairly safe to say that we are quite evolutionarily different from what we were 1,000 years ago as a species. Since we are no longer dependent on hunting and gathering skills to survive, we are no longer built to do it well. As a species, it is likely that our eyesight and hearing, among other things, have deteriorated as they have become unnecessary for survival.
Our physical digestive system has also been modified in several ways. Most notably, our appendix, which not so long ago was there to help us process drinking from natural water sources laden with microbes, and sediments, now is, for the most part, an inactive vestigial organ (recently some research indicates that the appendix does still provide some benefit). It is safe to say that if all of our modern conveniences were removed tomorrow, as a species, we would have a tough time adapting to the hunter-gatherer existence we dominated so well before.
As I have reported in earlier articles, most recently, “Treatment-resistant bacteria threat rises: What are the options?” we have removed ourselves from natural selection, using artificial means to survive. These survival improvements have come at a significant species cost. We are more susceptible to disease, we are less capable of surviving in a natural environment, and we are not equipped with the skills and knowledge to hunt or gather. Most of us, if thrust into the wild, would survive for a time, but likely at some point we would eat some toxic mushroom or, has happened to those thrust into the wild, successfully killed a predator (meat-eating animal), and made the mistake of consuming that predators liver, which can prove fatal. Eating the liver of an herbivore is ok, and we do it all the time.
The laws of natural selection were there for a purpose in our past. They kept us abreast of the changes in the species that either preyed on us or competed with us for survival. We, fortunately, evolved this big brain thing! Our big brain has allowed us to create artificial means to remove those natural selection pressures from affecting our current survival. But, like almost everything we find in the natural world, Sir Isaac Newton’s law of physics, “For every action there is an equal and opposite reaction,” or in modern parlance, the law of unintended consequences still holds.
Truly, there is little we can do other than to continue on this path and recognize that these consequences will continue to pile up. The pessimistic view is that this pile of unintended consequences will become fatal one day, and we will be wiped out as a species. The optimistic view is that perhaps our big brain will continue to seek solutions. We may find some method, perhaps a genetic means to reconstitute our DNA and rebuild the biological assets we have failed to evolve naturally. We will eliminate or reduce the building consequences pile.
Who knows? My humor actually shook my vegan friend in a way I did not intend, my own unintended consequence. She decided to eat more seafood, as she felt they likely felt nothing and, for the most part, were dead and cooked when she ate them. A few years later, she reverted to eating foul, as she read that they were determined to really be modern dinosaurs and were primitive and aggressive. Then a few years later, likely in a WTF moment or as a result of a building craving for a nice juicy hamburger, something she had told me over the years was the only thing she missed, she went back to being a true omnivore.
The story’s moral is that you can say what you want; you can eat what you want! What has built us as a species is 10s of thousands of years of evolutionary selection pressures. While today we have done a great job of eliminating those selection pressures using artificial means, including biochemical weapons on microbes, it comes at an accumulating cost.
These costs are not just figurative but fiscal and environmental as well. All biological populations pay a consequence for overconsumption and overpopulation. We, with our big brains, have derived ways to forestall this. Eventually, these costs will come due in one form or another! Will we be ready when the bill comes due? Are they already coming due now?