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Stupid question about Mutualism

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Stupid question about Mutualism

Postby justpassinthru » Fri Oct 06, 2006 9:24 pm

Hi folks, newbie here with a really basic question which I can't seem to figure out.

What is the scientific term for when one animal adopts another animal of a different species?

Examples:
Dog adopts kittens
Cat adopts puppies
etc
http://dogsinthenews.com/issues/0204/ar ... 20410a.htm

As far as I can tell, it falls under the general category of "mutualism", but mutualism seems to be more of a broad term which applies to populations of species rather than individual aberrations.

Can someone help me out? I'm writing an article which touches on this subject, and I'd like to have some good scientific facts & statistics to back it up. Any websites or journals you can suggest will be much appreciated!

Thanks,
Lyn
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Postby kiekyon » Sat Oct 07, 2006 8:11 am

altruism maybe??
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Postby justpassinthru » Sat Oct 07, 2006 10:23 pm

kiekyon, I think that's it! I googled "altruism between species" and got a ton of stuff. :D

keef, lol maybe it's confusionism too! or Confucianism, depending on what chinese philosophers they read :wink:
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Postby MrMistery » Sun Oct 08, 2006 4:06 pm

NOT altruism.
altruism is a very weird thing if you look at it from the point of view of evolution - an individual sacrifices it's own well-being in favour of another organism. So, what's the deal? Well, we need to understand what inclusive fitness is. Let me demonstrate: if a father riscs his life to save his 3 children, he will actually increase his fitness since every one of them shares 50% of his genes with him. therefore, the conclusion is: ORGANISMS ONLY PERFORM ONE-WAY ALTRUISM TO ORGANISMS THEY ARE CLOSELY RELATED TO.
The before-mentioned cases are not altruism, since they involve different species. it's more a case of "confusionism". it is similar to a bird raising a coocoo after a coocoo egg has been deposited in it's nest.
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Postby kiekyon » Mon Oct 09, 2006 7:22 am

i would disagree, altruism can occur two way and occur between different species. this is called reciprocal altruism..
how do you get confused between kitten and puppies anyway???
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Postby justpassinthru » Mon Oct 09, 2006 3:10 pm

Right, "interspecies altruism" exists (google it and you'll find a bunch of technical papers written on the subject). So far no scientific theory has been able to explain it. But it happens far too often to be ignored.

MrMistery, what you said is true also--it goes TOTALLY AGAINST the modern theory of natural selection. But that just tells me that the theory of natural selection needs to be "fixed". ;)

Here's a great read:
"Altruism: The Thorn in Darwin's Side"
http://www.u.arizona.edu/~jons/Altruism.html

Also a neat article about wild dolphins who rescue humans from sharks:
http://www.hindu.com/2004/12/14/stories ... 511000.htm

I've been reading thru Darwin's "Origin of Species", and he mentions it briefly, saying the phenomenon is "insuperable, and actually fatal to my theory."
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Postby AstusAleator » Mon Oct 16, 2006 6:32 pm

Altruism in the form of kin selection, like Mr.Mistery was talking about, fits perfectly in the model of Natural Selection.
Furthermore, interspecies cooperation (or altruism if you want to call it) could as well.
Sometimes argument against this will point out how individual fitness levels, or even micropopulation fitness levels are decreased by these actions, but one must look at the overall picture.
People tend to think of natural selection as a process by which ideal situations and ideal organisms are produced. They tend to ignore the other side of the picture; that by nature, the process calls for the decreased fitness, extirpation, and eventual extinction of every species.
Case studies that show altruism as having a net negative effect on the fitness of a population or species, are simply demonstrating the process of natural selection at work.
That population will either die off because of its low fitness, or it will adapt and increase its fitness. It would be good for scientists to monitor populations in this stage in order to witness first hand the processes of natural selection.

Also, it could be that the population has resorted to this altruistic behavior as a "lesser of two evils", in which if they had not adopted the behavior they would have suffered a much worse impact on their fitness.


Anyway,
Dogs are not a good example of a "natural" organism exhibiting this "altruistic" behavior as they're the result of thousands of years of coevolution with humans. Many of their behavioral traits are based on a different fitness paradigm than their ancestral wolves.


In the case of coocoos, I wonder if the host bird even realizes the difference? You'd think it would... Anyway that's a type of parasitism isn't it?
What did the parasitic Candiru fish say when it finally found a host? - - "Urethra!!"
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Postby Azedenkae » Sat Nov 18, 2006 12:54 pm

AstusAleator wrote:Altruism in the form of kin selection, like Mr.Mistery was talking about, fits perfectly in the model of Natural Selection.
Furthermore, interspecies cooperation (or altruism if you want to call it) could as well.


According to a revised Hamilton and Kin Rule, or something like that, we have this formula thingy:

An animal would commit an atruistic act when this equation is satisfied: rB>iC, where r is the relativeness of the animal, B is the 'benefit', or how many extra animals would be produced, i is the risk of dying and C is the 'cost', or how many extra animals wouldn't be produced.

For example, using MrMistery's example, we will have this:

Assumptions:
-The father can either rescue all 3 or none at all
-Each of the sons produces 2 extra individuals
-The father doesn't 'reproduce' anymore

We have:
r=0.5 (relativeness, or in other words, gene sharing)
B=6 (2x3) extra individuals produced if the 3 are saved.
C=0 because he doesn't reproduce anymore.

If this is the case, then rB would be greater than iC for sure, because the father cannot reproduce anymore, but if he saves his sons, his genes will be passed on whilst if he doesn't, none of his genes would be passed on.

Since the father in theory has 'nothing' left to lose, saving is a right thing to do.

Let's consider another case (taken from Biology 7th Edition Written by Campbell~Reece)

Story:
-2 brothers, who are very very similar to each other.
-One is currently drowning in a surf
-The other has a choice of swimming out to save the first brother, or leave him.

Assumptions:
-Both haven't reproduced yet, but is capable of producing 2 extra individuals each.

So:
B=2 because if the brother is saved, 2 extra individuals would be produced.

r=0.5 because they theoretically share half of their parent's genes.

C=2 because if the 2nd brother fails to rescue the first, they will both die, so 2 extra individuals won't be produced.

Let's consider a few situations.

Let's say the 2nd brother is quite an experienced swimmer and the surf doesn't have much hazards, the chance of dying is 5%

i=0.05, so we will have this:

rB = 0.5x2 = 1

iC = 0.05x2 = 0.1

Since 1>0.1, the 2nd brother will commit the artruistic act, because since he 'shares' half of his genes with his brother, saving the brother would mean half of his genes sent to the brother's next gen.

Let say, for example, there is a great storm and the sea is very dangerous, or there are 10 sharks in the water, the chance of the brother dying whilst attempting to save the other is 90%, i=0.9

So iC = 0.9x2 = 1.8

Since in the example, rB<iC, the 2nd bro wouldn't commit the artruistic act because it is too risky.

As the distance increases, r decreases, so it is less likely that an organism would help another.

In other animals, let's say, bees, which are almost always social.

We can sort of verify why worker bees are willnig to sting (die) to protect their hive.

Since worker bees don't produce offsprings, we can say that the cost of stinging (dying/artruisitic act is 0).

On the other hand, by doing this, the benefit would be countless offsprings produced by the queen bee, so basically rB would be much greater than iC because iC = 0, and rB = 0.5B, and B is a lot.

Which brings us back to the cat and dog case.

Although they're both mammals, they are distantly related, so its very strange although might be explainable.

However, the Hamilton and Kin Rule cannot be applied, simply because due to the distance, the relativeness 'r' would be so close to 0.

Anyone have any revised rule we can work upon to theorize the reason behind dog+cat relationship?
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Postby AstusAleator » Tue Nov 21, 2006 9:29 am

Dogs and cats are extremely complicated examples to use, as they are the subjects of thousands (more or less) of years of genetic engineering by humans. The complexity of human intelligence is reflected in the complexity of selection factors seen in domesticated animals.
A more proper example might be a bird raising a cuckoo chick, as mentioned earlier.
In the case of cuckoos, it's possible that the cuckoo is able to completely convince the host parent that it is simply an abnormal but acceptable natural offspring. It may accomplish this through scent, and its ability to mimic/learn the particular signals, both auditory and somatic, used by its hosts. So, while it may be visually different, it is capable of convincing its hosts that it's perfectly normal.
In that case, I suppose it would be a parasite/host relationship, in which fitness is not being knowingly sacrificed for the good of another species. Essentially, the parasite is taking advantage of a pre-existing altruistic relationship (parent-child).
What did the parasitic Candiru fish say when it finally found a host? - - "Urethra!!"
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