Since I'll be using PZMyer's lab, I'll have access to plenty of zebra fish. As per being in his Neurobiology course, I get to design my own experiment.
Zebra fish are schooling fish. If they are isolated, I wonder if finding another fish would be their top priority. Would it be high enough that they would navigate a few turns to find? Would it be higher priority than food? It looks like I may be testing the power of a social reward.
Some other random thoughts:
In class, we bounced the idea that deer are the perfect example of depression and suicidal tendencies in the wild. Who else would stand in the middle of the road and just stare at the oncoming car?
Edit: don't take the above comment literally. It's more of a joke than it is a valid scientific statement. I hope the Grinch didn't steal everyone's sense of humor last Christmas!
Anyways, I look forward to learning more about neurobiology. Interestingly enough, I'm taking Intro to Psychology for one of my gen-eds. It will be fun to look at thought and nerves from two different ends.
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I wonder, are you testing the power of social reward or the power of sociality?
Of course, they're related, but I'm guessing reward would be a sub-part of the broader issue of being a social species. Is food a reward for taking part in some broader social practice, like hunting? (for example, are those who don't take part in the practice of finding food exclluded from eating it once it's found?) Is the ability to find food, and the techniques for doing so, a learned behavior for the species?
I guess what I'm saying is that it sounds interesting, but some conceptual clarification will be very helpful for you in detailing how the experiments will be carried out, as well as what exactly the research question is.
Sounds like a fun biology class!
Regarding your classmates' thoughts on deer depression and suicidal tendencies; it seems like you've let a little bit of anthropomorphism go to far. If I was researching the deer-in-headlights phenomenon, I would start with deer eyes and image processing in the deer brain....at least find out why deer seem to be dazzled/confused by headlights and frozen into action. I'm guessing they're blinded by the lights and are unable to discern the motion of the car bearing down on them.
PS - I like your planned experiment on zebrafish schooling. Sounds like fun!
Deer have excellent low light vision. The biggest draw back of excellent low light vision is a greater tendency to be dazzled by bright lights. In addition, deer get fascinated by bright lights. Hypnotized that is. And, let's face it, deer are stupid.
Then there's the fact deer are not true herding animals. Most of the time they live solitary lives. When seen in groups it's often because deer congregate in open areas because they see, hear, and smell other deer in the same area. They form groups under the old principle of, "Having others around lowers my chance of getting killed." Yes, cervids do like the company of other cervids, but they don't act to support other cervids, and will abandon an injured fellow.
You want herding animals with smarts, study cattle. Cattle, regardless of species, will go to assist other members of a herd, and adolescent bulls will gang together to investigate something new.
By the same token. One existing reason for schooling is to limit risk. If there are 20 fish and a predator attacks, you have a 19:20 chance to survive, as apposed to what ever the odds are if you are alone (slim to none in most cases). So, even if fish schooling where to prove stronger than food acquisition, this won't necessarily tell you anything. After all, the odds, in a school, of you getting fed 100% of the time is probably lower than if you are alone too. This is something that is likely to be highly variable across species, depending on food resources vs. predations, and the general costs of one compared to the other in the environment.
I like this idea. You write really well, sound smart, and it's an interesting experiment for something you can do within the scope of an undergrad class. Lucky PZ for teaching you guys!
A big thing to keep in mind when coming up with animal models of known human disorders is not only replicating the symptoms, but also replicating the treatment. Depression in humans can be treated with stuff like SSRIs and MAOIs. If a behavior in animals shows analogous symptoms, and those symptoms are alleviated by analogous treatment, then it's likely that you're looking at analogous neurological mechanisms.
In the lab, a good example is learned helplessness in mice. It's likely you'll hear more about this in Intro Psych, but here's a quick rundown: Let's say you put a mouse in a box with an electrified floor. There's a door in the side of the box. If you shock the floor and the door is open, the mouse will jump out away from harm. But if the door is closed, the mouse learns to sit and take it. After a few trials like this, put both kinds of mice in the shock box with the door open. The open-door mice jump out, just like before. But the closed-door mice stay in the box, even though now they have an escape route; they have learned helplessness. The learned-helplessness mice also show other signs of depression.
Now, the big test: when we treat learned-helplessness mice with anti-depression drugs, their symptoms are alleviated, including being more likely to try and escape the shock box.
As for examples in the wild, we might ask if deer in the headlights would dodge traffic more quickly if we administered SSRIs. If the drugs have an effect, then maybe there is a similar mechanism at work. But it's especially hard to predict that since the deer-in-the-headlights behavior is the norm, not a symptom of a disorder.
For a better example of psychological disorders in highly social animals in the wild, I recommend this article about elephants that seem to be suffering from PTSD.
Of course, it might be hard for you to study elephants for PZ's course, so maybe experiments on fish or cows would be better. :-P
Stop wasting your time with fish. Why don't you kids do something constructive like invent a herd of self-tenderizing cattle? They could throw themselves down a flight of stairs, beat one another up, and make really, nice, tender steaks.
As far as fish are concerned, go with the self-smoking salmon. Get them up to a pack and a half a day of hickory smokes, and I'm all for it.
Mind if I add just a tiny bit to the deer in the headlights discussion? (It may or may not apply, of course...)
I've always been grateful that an early bio teacher told us that the "fight or flight" reaction was an incomplete description of the "4 F Rule." The four F's being fight, flight, freeze, or, um... screw. Those additional F's seem to explain an awful lot of the reactions by people I've worked with.
When my wife breeds them in the lab (Zebra fish are her model, too) the males will, at times kill the females during the stimulation phase. That, and other behaviors they exhibit, would tend to make me believe that Zebra fish are probably too stupid for your experiment to work.
I'm no expert and I freely admit I could be wrong. But I'm just thinking that they're a poor model for this kind of experiment.
Sounds like a damn good reason for so many of them to get depressed then.
Um, I think he was being facetious about the "suicidal tendencies" of deer.
I like the idea of the experiment with the zebra fish, but it sounds incredibly difficult to design and put into practice.
There is safety in schooling it is harder for a pedator to grab a fish that is in school, and at least when they do there is a good chance it is not you.
For this reason it might be interesting to see if your single fish was more motivated to school if you put a model of a big predator fish in the aquarium with it.
The real problem with deer is that they don't see machinery as a threat. I can drive up to within 10 feet of a deer on a garden tractor, and it won't budge. But if I get off the tractor, I suddenly become something with legs, and the deer bolts.
How wonderful that PZ's students can get instant feedback from the author of an assigned task. I wish I was in his class, so I was in a position to really participate in that discussion.
Start with mice. Accelerate the darwins and it'll be an elephant in 20 years.
Sorry... just a dumb in-joke.
Who else would stand in the middle of the road and just stare at the oncoming car?
Armadillos.
And they have a startle response that puts them at the level of the bumper or grill of most passenger vehicles.
But y'all are probably Edentata-deprived, up there in Minnesota, and thus not familiar with Nature's Little Tanks. :-(
For mice, there are many ways that social behaviors can be monitored and assayed; I'm not sure whether this is the case for zebrafish. Female mice, for example, will usually gather up and "nest" with pups that aren't their own-in fact it can often be difficult to tell who gave birth to the pups, in a cage with several breeding females (almost all will at least look as if they're lactating). I think if female zebrafish found eggs or larvae that weren't their own, they'd just eat them.
I always thought of deer as a good example for an animal where the FFF(fight/flight/freeze) reaction got selected heavily for freeze rather then either fight or flight
Having hunted birds a great deal I can attest to the difficulty of selecting a single prey from a school (covey). It took me a several years to be able consistently to focus my mental energy on a single bird when several are rising into the air. When twenty quail or Hungarian partridge burst from the brush a few feet from you - it is an event that seems to trigger a panic-like response - the emotional equivalent of, "with all those birds I better start shooting before they all get away". Of course, when you do that without picking out one target - they all usually do a get away.Prey and predators co-evolve - and in such a way that both tend to produce healthier populations in a stable environment. Perhaps the neurological response of predators to schooling prey is also something worse researching.
I laughed. And, I'm still laughing. So, never apologize.
Having driven in Minnesota for a number of years, I never hit a deer. I have, however, twice had deer hit me while I was driving.
Expanding a bit on MAJeff's response (#1), you might have some interpretation questions if you find evidence for non-isolation behavior.
Pack hunting? Mate seeking? Mutual grooming, a la primates? Fluid mechanics, a la geese?
I like the idea of the experiment with the zebra fish, but it sounds incredibly difficult to design and put into practice.
Not necessarily. You could put some walls inside an aquarium to make a partial "labyrinth" and see how the fish navigate in the presence and absence of various factors. A complication with this is that the fish may detect chemical cues from conspecifics in the water even if they are not in visual contact with them.
They're not very filling. I recommend you stick with walleye. Plenty of good recipes are available on the web.
Barn Owl...there's a good reason armadillos are called "Texas speed bumps"! I can remember slamming on my brakes many times when driving in Texas because of one of those darn critters. As for deer...well, I've never hit one, knock wood. But I have a friend who was killed by one who jumped in front of her car, landed on the hood, and, in the process, put his/her/its hooves through the windshield and into her.
Can't speak about the zebrafish, except to say they are "purty to look at".
windy (#23): Practical considerations are one thing, but I think the greatest hurdle is drawing valid inferences from observed behaviour. I think this might be somewhat problematic with zebra fish.
Of course I'm no expert on zebra fish and I haven't exactly thought this fictitious experiment through.
Yes. armadillos leap straight into the air when startled. This helps them when startled by ocelots, bobcats, coyotes, cougars, and jaguars. It just slams them into the grill or the underside of a car.
But why all the work on zebrafish? T. albonubes, the White Cloud Mountain minnow, is just as easy to breed and has pretty red fins. Neither species forms really tight schools like bloodfin tetras do. White Clouds are illegal in many northern states as they can often survive a freeze-over.
I have bred fish professionally and have worked in fish shops. Fish have taught me the roots of conformity. Fish are better at noticing a fish that another fish has found food that they are at noticing a food cource right above their heads.
Surely, the main threat to a deer in an evolutionary context is a predator, that comes looking for it - staying stock still is a good way to reduce the chance of being spotted (movement, shape, shine, tone etc).
Of course, if the apparent predator is actually a blind force entirely irrelevant to a deer's world, this is highly stupid. But them's the breaks when you haven't got the wiring for symbolic learning.
Well, I've only been in one deer-vehicle collision, so take this with a grain of salt, but... that particular deer DID try to jump out of the way. But it jumped too late, because it had faith that no object could possibly be moving faster than 15, maybe 20 miles per hour, so those bright lights arrived a little earlier than the deer expected.
If your brain is evolved for a world where you have plenty of time to react to threats that are still a quarter-mile away, it's not that surprising that your reflexes might let you down around "impossibly" fast-moving things.
How can you get any data about how strong a social reward zebra fish have? I mean what are you hoping to learn. Say you discover it's 1.5 times as strong as the hunt for food, what does it tell you? Seems like it tells you nothing of benefit. Why not devise an experiment that doesn't seem so worthless.
Deer gave evolved to deal with a certain array of predators, and not enough time has passed for them to deal with large metal objects with bright lights moving 60mph (or more).
One joke (in PA) is that deer are going to evolve hunter orange pelts, single spike antlers only, and learn to go into complete seclusion for three weeks of the year. (The second item above being a reference to antler restrictions currently in force for hunting.)
And getting into adaptions you can ask why North American antelope can hit 60mph when the fastest predator they have can not run anywhere near that fast (35-40mph tops IIRC).*
- Kurt
* - My brother, who geosciences teaches in the New York university (SUNY) system uses this in his intro course exams in drawing inferences about the existance of cheetah fossils.
Its probably best that you learn it now, there is no 's' in 'Anyway'
;)
Bah! Deers in headlights are proof that God exists and that he loves us.
And that he doesn't want us to drive too fast, because then we mash up all that lovely venison (and kill oncoming drivers by propelling the carcass through their windshield).
Now excuse me while I text my sister and ask her to put a leg aside for me.
Bodega Bay Marine Labs here in California has (or used to have) a sign on the road leading out there: "Caution: Suicidal Deer". Hee.
Re: fish
Would a lonely zebrafish school with non-zebrafish? Is the desire for socialness strong enough to overcome species boundaries? How does a zebrafish even find other zebrafish--wander around until it stumbles across an existing school?
How do school form in the first place? Possible analogy with seagulls: seagulls are interested in whatever at least one other seagull is interested in. So, should you ever need to attract a flock of seagulls, all you need to do is attract one. (Food works.) A second gull will come by to see what the first one's doing; a third one will want to see what those two gulls are doing; and the rest by induction. If there are two zebrafish, will they continue on their own as a mini-school of two and let other fish join them, or will they try to join a larger school? What about a mini-school of three fish? Four?