Why did this happen?

[eponym]

Hi.

First, sorry to have taken so long to reply. I had a couple of dive days, and put in extra days at the dive shop as well. I wanted to locate the article I (dimly) remembered before concluding.

Second, sincere apologies to Smoking Mirror and Xanthro. I can see that I came across quite testy and argumentative, and not a little ignorant. You were both right to point that out. What could have been in my head when I implied that all current traits must have evolutionary value? I'll never know. And I completely misread Smoking Mirror's first post. I hope you'll accept my apologies.

It turns out that the monograph I remembered was in the journal Science. Here's a summary and the reference, for anyone who's interested:

"Motion sickness has been called an evolutionary anomaly because it seems highly disadvantageous to those who suffer from it. Yet, motion sickness occurs in many species. Why should it have evolved at all? Recognizing this problem, Michel Treisman seeks to explain the anomaly by noting that neurotoxins accidently ingested by animals cause essentially the same symptoms as motion sickness. To survive, animals must eliminate ingested neurotoxins by vomiting or defecation, both of which also accompany motion sickness. It is simply coincidental that modern vehicles duplicate these symptoms through their motions. The body interprets the signals created by motion as due to dangerous ingested material and acts accordingly."

Treisman, Michael; "Motion Sickness: An Evolutionary Hypothesis," Science, 197:493, 1977.​

Charles Oman, of MIT, is involved in motion sickness research for NASA and has some interesting papers as well. Can't locate them either just now,sorry. But I know his work because we're both sailors—he gave a nice summary of seasickness prevention and treatment in Cruising World, in 1991 I think. I won’t try to summarize off-the-cuff again, as I don’t do it well.

Again, apologies to anyone I offended. ScubaBoard’s a great place to exchange ideas and share anecdotes. I don’t want to lessen the viz, so to speak.

Fair winds, calm seas!
Bryan

PS: regrding the usefulness of the appendix, I can't claim any special medical knowledge at all. Sorry if I somehow implied that. Here's a quote from my old Encyclopedia Britannica, sitting on the shelves behind me:

"[The appendix] has no known physiological function but probably represents a dengenerated portion of the secum [the entrance to the large intestine] that, in ancestral forms, aided in cellulose digestion. [. . .] In other animals, the organ is considerably larger and provides a pouch off the main intestinal tracts, in which cellulose can be trapped and subjected to prolonged digestion."​

 

[Xanthro]

Bryan St.Germain,

I do not think you address me directly at all in this thread, much less in a testy and argumentative fashion. You owe me no apology.

I found the thread to be informative. I'm surprized at the number of people who get seasick.

Me, I tend to get land sick after diving. Eating is especially bad. It seems that the table is moving.

I wanted you to know I found nothing in your posting to warrant an apology to me.

Xanthro

 

[eponym]

Me, I tend to get land sick after diving. Eating is especially bad. It seems that the table is moving.

Wow. That does not sound at all pleasant.

When consumer VR headsets first came out (15 years ago?) I was heading up a multimedia institute and I was amazed at the number of reports of induced motion sickness from headset use. Then I tried one. Really did make my stomach twist.

Bryan

 

[SmokingMirror]

Thank you, Bryan. Although, in point of fact, I should also apologise to you. Reading back over our posts, it is obvious that I responded to you in an equally argumentative way, which didn't help the ongoing thread and only served to back two posters into their various corners growling at each other until one was mature enough to come forward and apologise.

The article you give is interesting, but whilst it is admittedly only a hypothesis, I'm still not convinced that there has to be an evolutionary reason for motion-sickness. I note that this hypothesis was published in 1977. I did a little hunting for something slightly more recent, and found reference to controlled experiments carried out in 1991 by Dr. Douglas Watt of the Aerospace Medical Research Unit, McGill University, Montreal, Quebec, Canada:

"The symptoms of motion sickness have been experienced at least since the invention of ocean-going vessels. It seems extraordinary that several millennia later, the fundamental nature of the disorder is still not understood. In particular, it is not clear why it exists at all.
Through the years, many theories have been advanced as to the cause of motion sickness, and at least some of these have implied a purpose. For example, if a particular activity involving movement were being overdone, this would lead to motion sickness, which in turn should cause the sufferer to reduce that activity. In a broad sense, motion sickness was thought of as a form of pain. Many possible mechanisms were suggested to link motion exposure to motion sickness, including shifting of the abdominal contents, disturbances of the circulatory system, and over stimulation of the vestibular system. AH of these ideas have since been disproved, to be replaced by Reason s "sensory conflict" or "sensory rearrangement" theory. Unfortunately, as its author carefully points out, this theory describes where and when motion sickness occurs, but not why. In fact, Reason basically dismisses motion sickness as the coincidental result of technology outrunning evolution, making the question itself meaningless.
Others have not been quite so willing to accept that the signs and symptoms of motion sickness have no purpose, but they also have not been particularly successful at defining what that purpose is. One theory that has been considered proposes that the vomiting associated with motion sickness actually reflects a mechanism for getting rid of ingested poisons. According to this theory, the fundamental mechanism is that poison reaches the inner ear (which is assumed to be particularly sensitive to that substance), resulting in vomiting and expulsion of whatever toxic material remains in the stomach contents. Motion, on the other hand, merely happens to activate this mechanism."

Plenty of theorising, not too much fact. Since he is still a member of the Faculty, I've emailed Dr Watt with regards to his research on motion-sickness, and will happily post my original email plus his response here when/if he replies.

 

[eponym]

Thanks, Smoking Mirror, and nice digging. That quote pretty accurately reflects my thinking--I know what causes motion sickness, but it also pleases me to play around with "what-if" stories that could explain why it came to be.

I remember a tantalizing reference to something else in more recent reading, which I've not been able to track down--perhaps you can. Summarizing from memory and briefly, it was about recent work on mapping brain functions which found that equilibrium processing (prioperception vs. vision?) happens in the same (or an adjacent?) location as stomach sensory processing. I may have garbled that badly.

I agree that motion sickness may or may not have an evolutionary origin. But it certainly makes for interesting table talk.

Bryan

PS: I know that many other animals also vomit. I wonder, has anyone ever tried inducing montion sickness in, say, a dog or a chimp? Not that I'd wish that fate on anyone . . .

 

[DandyDon]

Me, I tend to get land sick after diving. Eating is especially bad. It seems that the table is moving.

Really. I am familiar with "getting your land legs back," for once I'm been a sea for a day of rock & roll, land objects continue seem to sway, or maybe it's me who's swaying.

I spent many childhood years working on rock & roll tractors - long before computer controlled operator suspention, and horses, down on the dirt & cow farm, as well as riding a cheap bid school bus 2 hours a day. I think the early conditioning may have made me more flexible?

I started flying trips with my daughter in her pre-teens and did a pretty good job of convincing her that we did not get motion sickness. We went on a cruise once in those days :sleep: and encountered some rough water in a boat without stabilizers at dinner time. Most of the passengers left supper quickly; we were reaching across the table for unwanted garlic snails. Yumm.

Ah, ever notice that the driver of a car or boat never gets seasick? Go to the flying bridge, face the front, hold the rail as if it were a steering wheel, watch forward as if you're in control.

 

[Mako Mark]

Ah, ever notice that the driver of a car or boat never gets seasick? Go to the flying bridge, face the front, hold the rail as if it were a steering wheel, watch forward as if you're in control.

My father in his wisdom while teaching me the finer points of heavy weather sailing used to say "if you have a sick crewmember, make them steer the boat" works too.

I have also noticed in addition to and probably more so, that not only do women tend to be slightly more succeptable to sea sickness, that certain ethnicities are.

Japanese and some other Asians seem to suffer horribly, while Norwegians and other teutonic or scandinavian groups could eat cold vomit from an old seaboot while standing on a heaving deck with impunity.

Doesnt seem fair does it.

As far as being a genomic trait that has some advantage, I think not so, rather I think it is a side effect to some other advantage. Increased balance or hand eye sensitivity trait has a disadvantage of being more succeptable to conflicting messages to the brain.

 

[STOGEY]

Maybe sea sickness is nothing more then body over the mind.

 

[SmokingMirror]

I know this thread hasn't been touched for a while, but I have just received an email from Dr Watt (see the end of post #24), and thought people might be interested in his response.

My original email:

Dear Dr. Watt,

Firstly, let me apologise for sending you an unsolicited email, but I have recently - as part of an ongoing discussion in the diving community - read details of your research that appeared in volume 656 of the Annals of the New York Academy of Sciences (May22, 1991. pp.660-667).

The publication date of this article was over a decade ago, and I am curious as to rather more recent findings with regards to the question of whether motion-sickness is linked to evolution.

I understand you have a busy schedule, and so greatly appreciate any time you can give to furthering our understanding of this question.

Kind Regards,

<my name>


Dr Watt's Response:

Dear <my name>,

It would be most satisfying to say that we now know the purpose of motion sickness, but it would also be untrue. Like many other general ideas, our link between the disorder and human evolution may be attractive but it is also next to impossible to prove. However, we continue to identify unusual motor strategies that alter vestibular function and produce motion sickness. In all of these cases, is the body saying "stop doing that" and would the same thing have happened many thousands of years ago? I simply don't know.

One of our methods that might be of interest to you involves active head movements while inverted. It turns out that the gravity-sensing part of the inner ear becomes highly non-linear in this orientation.
As a result, there is a conflict between actual and predicted
vestibular inputs and a rapid onset of motion sickness signs and symptoms. Some years ago, we studied this phenomenon as a possible model for space motion sickness and chose to perform the experiments underwater to avoid hydrostatic problems. The results were reported in the Canadian Aeronautics and Space Journal vol. 42: 128-132, 1996.
As an aside, I had first experienced the effects of inverted head movements as a novice diver in the late 1950s. It only took me 35 years to figure out why!

Best regards,

D. Watt, M.D.,Ph.D.