Is this current ecospeak for “preying on”?
(And I thought “gifting” was a fairly awkward and useless replacement for “giving”!)
No, it’s a technical term of pretty long standing, frequently found in the scientific literature. It does mean “preying on.”
This thread reminds me of this Far Side cartoon.
Brightly coloured animals that are not poisonous tend to be those tropical birds. I assume in a jungle environment you are a lot more protected than on an open plain; and being birds, they have an easy way to escape non-bird predators; and birds big enough to prey on them have trouble maneuvering in the closed jungle. So the other evolutionairy pressure “pick me honey, I’m the brightest guy around!” will win out.
Not sure what the logic is with reef fish, other than there’s so many bright colours and hiding places they need to be flourescent to fit in? Or is it the herd thing - there’s so many that maybe the guy next to you will get eaten instead?
That’s the nice thing about life - it’s full of surprises.
Thanks for the patronising wit. But actually, my question was not about whether learning does or does not occur. It was about how this learning might be achieved.
Or, in the case where the prey is or was toxic, that parent is now dead and is unable to teach a lesson to anything - as far as its children are concerned, Dad just tried to fight that snake and the snake won.
How would they do this?
My concerns were not about whether you were simplifying. I respect the need to simplify, and I admire the ability to do so. My concerns were about whether the arguments and reasoning you presented made sense.
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Tropical =/= jungle. Most of the tropics are deserts and savannas.
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The brightest tropical birds I’ve seen are the parrots and finches of the semi-arid and arid savannahs and deserts of Australia and India.
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The bird most people think of when you say “flamboyant” is the peafowl, another species perfectly at home in the semi-arid savannas. Peacocks are not known as great fliers.
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Most parrots are smaller than a pigeon. There are plenty of jungle raptors that are capable of taking birds of this size, along with shrikes, butcher birds, monkeys, civets and a whole slew of other predators.
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Brightly coloured does not equal conspicuous. Despite their flamboyant colours, most of the parrots are quite hard to see in their chosen habitat when they are motionless. In contrast the solid black or solid white cockatoos stand out like dog’s balls in rice pudding. As do crows, egrets and other monochrome fowl.
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Most reef fish are solitary or found in schools of less than 10 individuals. There’s no obvious correlation between school size and colouration.
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There are so many tropical reef precisely because the animals are so brightly coloures. Neither the water nor the rock nor the mud are brightly coloured.
I don’t see how this can work and would welcome a little more detail. Can you please tell me how, by transferring DNA, an adult can pass on to his or her offsrping a fear of a given pattern of colouration.
Why would it need to be any different to the way that any other learning is achieved?
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You think that when a child sees their father killed by something, they won’t avoid it afterwards?
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Most cases of poisoning don’t result in death. Untreated a rattlesnake bite has, what, a one in ten chance of killing a coyote. Chewing on a toad about one in a thousand.
If you can point out what you think doens’t make sense, I’m sure we can help. At this stage the only thing I’m not seeing any sense in is your apparent claim that seeing his father torn to shreds by wolves won’t make a child wary of wolves.
All animals instinctively fear something. I assume you accept this. Cockroaches don’t need to flee the light. Humans don’t need to be told that skunk spray smells bad. They don’t need to be told to be afrand of heights These are instinctive reactions. They are passed on via "the DNA: as you put it. And like every other genetic trait, what we fear and how much varies. Some people are incapacitated by skunk spray, some find it merely unpleasant. Some people have an instinctive fear of the dark or of heights, some don’t.
So an organism can have a brain structure that makes it instinctively wary of anything. Wary of the smell of lions. Wary of the smell of the shape of snakes. Wary of heights. It all depend son how the brain is wired up. There is no limitation on what an organism can instinctively fear.
An organism born into a world where all poisonous animals are bright yellow and black that has mutation that makes it wary of yellow and black patterns has an obvious survival advantage. While its siblings are finding out about the danger by approaching such dangers casually and being poisoned, it instinctively avoids the colours. As a result that mutation both spreads and becomes stronger.
This is no different to the mechanism by which we instinctively avoid heights or the dark or skunk spray.
In a way, this was a compliment (admittedly a back-handed one;). I know you as a generally savvy poster, and the fact that you were having a problem with a concept that seems to be pretty self-evident to me was surprising.
Sorry, I didn’t get that sense from your post. You said you didn’t understand this point “at all.” You might have been clearer about what you were asking.
As Blake says, learning about toxic prey happens the same way that any other learning happens. Parent animals (at least of higher vertebrates) often teach their offspring what is good to eat and what isn’t. When their offspring are in a nest or den, they bring in certain kinds of food, and the offspring learn that it’s good to eat. In some cases, food items that aren’t offered to them may not be recognized as prey when they are adults. They go out foraging with their offspring, and point out prey for the offspring to catch. If they see toxic or dangerous prey, they give alarm calls to alert the offspring to avoid it in the future.
If the offspring actually saw a parent killed by a snake (especially if the parent were giving alarm calls as it succumbed), you can bet that they would learn to avoid snakes in the future. If the other parent survived, it would be giving alarm calls towards the snake as well.
Predators such as snakes and owls often elicit “mobbing” behavior by small birds. If such a predator is discovered, a flock of several species will gather in response to alarm calls given by the bird that first sees it. The flock will often harass the predator from a safe distance until it leaves the area. This behavior will serve to teach naive birds in the area that this kind of animal is dangerous.
With all due respect, some of the points you raised were covered in earlier posts in this thread. I got the impression from your post that you hadn’t read the entire thread.
The problem I have with this is that we know of no such world. In this world, the one that we live in, it is not the case that everything dangerous has a given coloration or that everything with that given coloration is dangerous. There is no correlation whatsoever. The same survival ‘advantage’ that comes from avoiding a dangerous snake with yellow/black stripes could equally amount to the ‘disadvantage’ of avoiding something with similar or near-identical colouring that would provide a healthy, nutritious meal. It seems to me that you are being selective with your examples because you have decided in advance what you want the conclusion to be.
I have many friends who work in the field of psychiatry and psychicatric therapy who suggest that, in the case of human beings, these fears are acquired through traumatic experiences, and have nothing whatsoever to do with genetic make-up. Indeed, they would scorn the very idea. I guess different scientists have different theories.
See, this is the problem with people askiing for a simple explanation for evolutionary problem. When you get given it, instead of simply accepting for what it is you want to immediately overextend it. Like all analogies and simplifications of course it fall apart if you overextend it.
But just for now, can you simply acknowledge that the simplification is correct and that you understand it. If you can do that then we can take you to the next level. But if you say, as you have, that you don’t understand the simplest examples, and then tr to use those simplifications as though they represented reality you will get nowhere.
You need to learn to walk before you try to run.
Well of course that is the case. And when a cockroach runs for cover when you turn on the light it *certainly *has to give up searching for a healthy, nutritious meal.
Nonetheless you don’t dispute that cockroaches run for cover when you turn on the light. Do you?
No evolutionary solution is every free of cost. The only important factor is whether the costs outweigh the benefits, as measured by the number of surviving offspring.
For crying out loud, I being selective with my examples because you said that you didn’t understand what is, to us, a very simple concept. So I created fictional simplified examples in a fictional simplified world, so hopefully you could comprehend the underlying principles.
Instead you seem to have made up your mind that “evolution” is wrong and want to argue details when you don’t understand the basics.
Shit, if you want to discuss complex, real world examples I’m quite happy to use any examples you like. We could discuss the prevalence of polyploidy in Myoporacea as it relates to fluoroacetate production if you wish. But given that you don’t understand the basic concepts I doubt that you would be much enlightened by it.
These friends are either liars, idiots or grossly ignorant. It’s as simple as that. Not only has it been well established that those fears are innate it has been established when they develop, how and even some of the underlying genetic basis.
That someone who calls themselves a psychiatrist or psychologist would be ignorant of this is inconceivable. Next they will be telling you that cockroaches only flee the light because they have been traumatised. 
It appears that some “scientists” are grossly ignorant of the *facts * within their own field. Theories based on that level of ignorance will certainly differ from the mainstream.
I suggest that you ask you friends to go back to their undergrad developmental psych texts and look up the term “visual cliff” in the index. It will be in any of them. After they have reviewed the material ask them again whether they think that human fear of heights is due to trauma. I think you will find they suddenly have an answer much more in keeping with the mainstream (ie all other psychologists in the world).
ianzin, this sounds familiar. Have you posted threads before about how we just don’t know how DNA can transfer behaviors and “instincts”?
I’m generally with you on “heights” and “dark,” but one of the things listed was “skunk spray.” Blake, are you saying humans develop an innate fear of skunk spray during routine development? Without exposure (i.e., traumatizing)? That seems a little far-fetched.
Do you really think that someone needs to be bitten by a skunk while simultaneously being sprayed in order to be repulsed by it?
That is just bizarre, and runs counter to every living person’s experience with skunk spray. Humans find the smell of mercaptans repulsive instinctively, as do most other mammals. That reaction is assumed to have evolved because in nature they are found primarily in anaerobically decomposing proteins. ie rotten meat, and they are a good indication of pathogens.
The idea that humans don;t have an innate fear of skunk spray is not just far fetched, it actually runs counter to *all *the evidence. But hey, if you have evidence of a human that only developed a negative reaction to the spray *after *the first exposure, then by all means present it.