Three legged aliens?

[Edtharan]

The sterile offspring are really no more than 'arms and legs' of the queen (and drone). The better your arms and legs, the better chance of passing your genes on.

Yes, but if evolution only worked on the genes, then the workers can not pass on their genes, so why did they evolve sterility. It is not for their benifit (and they would have mutations that might make them more fit than the queen), so why did they evolve away the ability to breed? The breeding bees do not have the exact same genetic code as the workers, so they are not necessarily promoting their specific genes.

 

If evolution does not only work on the level of the genes, then such a situation makes more sense as it is a benifit of the group (and the similar genes in the group).

[Paralith]

Yes, but if evolution only worked on the genes, then the workers can not pass on their genes, so why did they evolve sterility. It is not for their benifit (and they would have mutations that might make them more fit than the queen), so why did they evolve away the ability to breed? The breeding bees do not have the exact same genetic code as the workers, so they are not necessarily promoting their specific genes.

 

If evolution does not only work on the level of the genes, then such a situation makes more sense as it is a benifit of the group (and the similar genes in the group).

 

The majority of eusocial insects have an interesting genetic set up known as haplodiploidy. Eggs that are unfertilized become haploid males, and eggs that are fertilized become diploid females. Now, in a normal diploid species where both males and females are diploid, parents share on average 50% of their genes with their children, as was mentioned previously, and full siblings share on average 50% of their genes with each other. In a haplodiploid species, however, full sisters share on average 75% of their genes with each other, but would only share on average 50% of their genes with any offspring might have. So it's actually in their reproductive interest to help their mother make more sisters than it is for them to have their own offspring.

 

However, while this is a convenient explanation in theory, it doesn't quite scan to reality. If a queen mates with more than one male, then her female workers aren't all as closely related to each other. For a queen, it's in her interest to have 50-50 male-female offspring, but it's in the workers' interest for the queen to have mostly female offspring. This is not to mention the fact that there exist eusocial species of insects with non-reproductive castes that do not share this genetic system, and vice versa.

 

The explanation closest to reality, then, is probably one that combines relatedness and ecological factors. A queen with workers around to help her will reproduce more often, and with greater success. A single worker breaking off on her own to reproduce will have much more difficulty in raising offspring, and ultimately may only be able to produce very few if any at all. So by sheer volume she is more likely to pass on more of her genes through contributing to the raising of sisters than by having offspring of her own.

 

Something similar happens in termites - they develop in stages, and their food source, wood, requires a long time to digest for a relatively small amount of energy. It can take years for an individual termite to become a fully mature, reproductive adult. So an individual termite in the middle stages of growth has a choice; they can continue to spend all their resources on their own growth, and in a few years have their own offspring. Or, they can stop growing and spend their energy helping their already reproductive parents have more offspring than they would be able to without help. Once again, the volume tends to win out.

[bombus]

The sterile workers didn't evolve at all. It is only the queens/drones that evolved to produce sterile workers.

[iNow]

The sterile workers didn't evolve at all. It is only the queens/drones that evolved to produce sterile workers.

 

You seem to have missed the point that even sterile workers can influence the reproductive success of their non-sterile sisters/brothers, and hence influence the overall gene pool in their direction.

[thedarkshade]

ALIEN INVASION SCENARIO

 

An alien spacecraft land on my yard and captures me when I'm asleep. They take me somewhere completely detached from everything, but in Earth. And they say to me that I'm gonna be the one who they will show everything I ask. I think and think and think and ask them a few questions. Here I go:

 

1. Are you laws of physics the same as ours?

2. In your world, do you have the concept of God?

3. Is politics a main part of your lives?

4. In your world, do you have wars?

5. What is the advantage of being a human?

 

Now I've been thinking quite enough, and getting all sorts of answers, but I thought I'd the best answers here.

 

So what would be the best and most sincere answers?

[Paralith]

ALIEN INVASION SCENARIO

 

An alien spacecraft land on my yard and captures me when I'm asleep. They take me somewhere completely detached from everything, but in Earth. And they say to me that I'm gonna be the one who they will show everything I ask. I think and think and think and ask them a few questions. Here I go:

 

1. Are you laws of physics the same as ours?

2. In your world, do you have the concept of God?

3. Is politics a main part of your lives?

4. In your world, do you have wars?

5. What is the advantage of being a human?

 

Now I've been thinking quite enough, and getting all sorts of answers, but I thought I'd the best answers here.

 

So what would be the best and most sincere answers?

 

Um - the answers would all depend on the aliens, who at this point are completely hypothetical and we know nothing about them. How are we supposed to come up with answers to questions that would be put to entirely unknown beings? The "advantage" of being human would be relative to the aliens' values. Even the laws of physics - now, I'm not a physics person, but I have heard that for all we know, the laws of physics as they work in our galaxy may only be local effects compared to the universe as a whole. So for all we know, even physics as aliens might know them could or could not be different.

[thedarkshade]

Um - the answers would all depend on the aliens, who at this point are completely hypothetical and we know nothing about them. How are we supposed to come up with answers to questions that would be put to entirely unknown beings?

That's exactly where I wanted to come.

 

WE KNOW NOTHING ABOUT THEM

and it doesn't mater at all man, why bother loosing time with these issues. It's non-sense!

[Paralith]

The sterile workers didn't evolve at all. It is only the queens/drones that evolved to produce sterile workers.

 

Like INow said, you're missing the point. If you as an individual can have greater reproductive success by helping to raise millions and millions of sisters and brothers instead of a handful of your own offspring, then why waste the resources on growing reproductive organs when you could instead become morphologically specialized in service of the hive?

 

That's exactly where I wanted to come.

 

WE KNOW NOTHING ABOUT THEM

and it doesn't mater at all man, why bother loosing time with these issues. It's non-sense!

 

I think the point of the thread is not to try and anticipate what aliens would look like or think or do, but to discuss what might be more or less likely, and why.

[foodchain]

The sterile workers didn't evolve at all. It is only the queens/drones that evolved to produce sterile workers.

 

 

Natural selection on genes does not have to make sense! It has to be fit in time/environment up to modern form is all! If AIDS became an airborne threat there is already a very small percentage of the worlds populous that are naturally immune via mutation, they would be the only ones to have a real chance of survival from just the AIDS variable.

[bombus]

You seem to have missed the point that even sterile workers can influence the reproductive success of their non-sterile sisters/brothers, and hence influence the overall gene pool in their direction.

 

No, I didn't miss the point. Its just that the 'ability' of sterile workers is based upon the genes of the queen. They cannot themselves influence evolution, as any ability they have to influence the gene pool was already 'coded' before they were born - in the queens genes.

 

I'm not sure, and will find out, but I think the evolving bit only involved the fertile queens 'inventing' the idea of 'sister' sterile workers.

 

Oh, and in answer to THEDARKSHADE the point of the thread wasn't really about aliens per se. It was about evolution (via natural selection), and what is possible and what is not.

 

Natural selection on genes does not have to make sense! It has to be fit in time/environment up to modern form is all! If AIDS became an airborne threat there is already a very small percentage of the worlds populous that are naturally immune via mutation, they would be the only ones to have a real chance of survival from just the AIDS variable.

 

Yes, but that makes sense and I can't see how it has anything to do with bees! If you were immune to AIDS but sterile, you wouldn't pass any genes on, no matter how immune you were!

[Paralith]

No, I didn't miss the point. Its just that the 'ability' of sterile workers is based upon the genes of the queen. They cannot themselves influence evolution, as any ability they have to influence the gene pool was already 'coded' before they were born - in the queens genes.

 

I'm not sure, and will find out, but I think the evolving bit only involved the fertile queens 'inventing' the idea of 'sister' sterile workers.

 

I wrote a paper once on the evolution of eusociality, and as I understand it the current theory revolves around the "choice" of the potential worker.

 

The eusocial ancestor was most likely some kind of parasocial insect, where the females were capable of polymorphic behavior. An individual female is face with a "choice" when starting a new nest; either form a multiple-foundress nest with relatives, where they stand of a good chance of never being able to have their own offspring (as only one or a few of the females will probably gain that privilege), or form a single-foundress next where they can be sure they will have their own offspring. (There are several species of insect alive today that are like this as well.)

 

As I mentioned in an early post, a lone foundress will often face a good deal more challenges than multiple foundresses. Getting the material for and building a nest will take time; foraging for food and bringing it back to the young will take time. If during any of these trips out from the nest the foundress dies, there will be no one else left to raise the young. In a multiple foundress nest, all of these challenges are reduced by the numbers of additional, helping adults. Participation in a multiple foundress nest will yield more offspring with a greater chance of success.

 

So, given significant selective pressure, the gene or gene suite that promotes the multiple foundress behavior will have more copies in the population's gene pool. Once you have the multiple foundress behavior fixed, then those groups of foundresses with some more specialized individuals may become more successful than those foundress groups that are not. From there you can evolve morphologically distinct castes that include completely sterile individuals.

[bombus]

Mmm, that's interesting.

 

I believe, though, that it developed via the evolution of queens having the ability to produce sterile workers, although in terms of Selfish Genes, it caould maybe work both ways.

[Moontanman]

ALIEN INVASION SCENARIO

 

An alien spacecraft land on my yard and captures me when I'm asleep. They take me somewhere completely detached from everything, but in Earth. And they say to me that I'm gonna be the one who they will show everything I ask. I think and think and think and ask them a few questions. Here I go:

 

1. Are you laws of physics the same as ours?

2. In your world, do you have the concept of God?

3. Is politics a main part of your lives?

4. In your world, do you have wars?

5. What is the advantage of being a human?

 

Now I've been thinking quite enough, and getting all sorts of answers, but I thought I'd the best answers here.

 

So what would be the best and most sincere answers?

 

If this ever happens please ask more pertinent questions, those are either irrelevant or not likely to be known by aliens.

 

Getting back on topic, three sexes might allow greater diversity but make it harder to find a mate. Two sexes might be a better trade off between diversity and mate finding. John Varley invented Three sexes for his trilogy Titan, Wizard, and Demon. His aliens were basically centaurs and each individual had three sex organs but only two individual sexes. Each individual was either male or female but each had either two penises or two vaginae but both had at least one penis and one vagina. there were twenty nine different ways (or some number close to that) for them to mate including an individual being able to effectively clone herself. They could mate the first time frontally to produce a viable egg and then implant the egg in a rear vagina and mate again to produce offspring. It made for a wild story but it's difficult to see how this could evolve naturally, the aliens were the result of ID.

[bombus]

If this ever happens please ask more pertinent questions, those are either irrelevant or not likely to be known by aliens.

 

Getting back on topic, three sexes might allow greater diversity but make it harder to find a mate. Two sexes might be a better trade off between diversity and mate finding. John Varley invented Three sexes for his trilogy Titan, Wizard, and Demon. His aliens were basically centaurs and each individual had three sex organs but only two individual sexes. Each individual was either male or female but each had either two penises or two vaginae but both had at least one penis and one vagina. there were twenty nine different ways (or some number close to that) for them to mate including an individual being able to effectively clone herself. They could mate the first time frontally to produce a viable egg and then implant the egg in a rear vagina and mate again to produce offspring. It made for a wild story but it's difficult to see how this could evolve naturally, the aliens were the result of ID.

 

I'd agree that two sexes is probably the optimum to provide enough diversity to out-evolve pathogens, whilst passing on the maximum number of genes. I can't think of a scenario where three sexes could evolve. Can anyone else?

 

What about the post-reproductive phase warrior scenario? Is that possible?

[Mr Skeptic]

Well, there's several critters where both their diploid and haploid forms can go about their business. Unlike our sperm and eggs, these forms can do fine on their own before joining together. Now consider if you had a triploid critter, which can have haploid and diploid phases as well. These could mate by joining a haploid with a diploid, or two haploids could join to form a diploid, and then the diploid could join with another haploid. If all three phases are viable and useful, this kind of arrangement could be possible. Getting such to work for a multicellular critter might be more complicated.

[Moontanman]

Since this thread was originally about the number of legs, three to be exact, how about six legs? Might result in a centaur like being. What could bring this about? Higher gravity?

[DrP]

Has anyone read "The Forever War" ? There are three legged aliens caulled Taurons in that book. Good read actually - About time dilation over long hauls space flights. It follows one bloke who joind the 'space army' or whatever they call it and he is there at first contact. Due to time dilatory effects as they travel from point to point across the galaxy - he ends up spanning hundereds of years of earth life and war with the Taurons and ends up being there at the end of it all. Every one looks to him for advise and assumes he's an expert because he has been part of the war effort for hundreds of years - but to him he has only seen a few battles and has aged very little and ends up way behind on all of the technology. Good book.

 

 

 

PS - it was written by Joe Haldeman in 1975 if anyone is interested.

[Sisyphus]

Since this thread was originally about the number of legs, three to be exact, how about six legs? Might result in a centaur like being. What could bring this about? Higher gravity?

 

So, you've never heard of insects, huh?

[npts2020]

Since this thread was originally about the number of legs, three to be exact, how about six legs? Might result in a centaur like being. What could bring this about? Higher gravity?

 

John Carter meet Tars Tarkus........I think it has been fairly conclusively shown there is no Barsoom on Mars tho.

[pioneer]

Logic is based on cause and affect which is a 2-D concept, with cause plotted as the x-axis and effect the y-axis. A three legged alien would imply the brain having more 3-D wiring to get a smooth rhythm out of three legs. If you walk with the rhythm one big leg and then two smaller legs in unison, this is still 2-D. This is sort of redundant for balance, and would default back to two legs.

 

If the walking gate is 1,2,3 step the brain wiring would need to be different, which would also affect how the brain is had been wired by evolution leading to the eventual thinking of higher humanoid life. The use of 3-D thinking would be an improvement over logic since it could anticipate extended relationships of cause-affect-cause or affect-cause-affect. This is a more creative way to think, allowing them to advance really fast. Our brains aren't wired this way.

 

I am not sure if your vision of the third leg is only superficial, sort of as a decorative affect, that has little to do with the requirements of brain wiring. Or 3-D wiring so their brain is set up quite differently. When we march it is left, right, left, right, etc, (cause, affect, cause, affect, etc). They will march left, middle, right... left, middle, right, etc). Their mind is thinking cause, affect, cause or affect, cause, affect, etc.), or something odd like that. Maybe less in terms of a rational proof and more in terms of any extra step before or after a logical affect. This would make them extremely advanced and very creative.

 

Chaos theory sort of uses such a approach of the terminal affect from a cause, but with a middle step that this up in the air and doesn't have to be logical but can still lead to an affect. The middle leg is sort of gimp. But with the alien since this would be natural for them, that middle step would be far more coordinated and predictable, so they could predict weather, for example, in their heads without a machine being their middle leg.

[Sisyphus]

Logic is based on cause and affect which is a 2-D concept, with cause plotted as the x-axis and effect the y-axis.

 

Huh?

 

A three legged alien would imply the brain having more 3-D wiring to get a smooth rhythm out of three legs.

 

So spiders and octopi have "8-D wiring?"

 

Seriously, are you just high right now?

[bombus]

Since this thread was originally about the number of legs, three to be exact, how about six legs? Might result in a centaur like being. What could bring this about? Higher gravity?

 

Insects have six legs already!

[Moontanman]

Sisyphus and bombus, yes I have heard of insects, I've never seen an insect as large as a man or capable of making tools or technology. Haven't you ever heard of centaurs? While I doubt a being would likely have hooves and hands a six legged being with four legs and two arms makes much sense especially in a high gravity situation. A vertebrate with six limbs would be better at crawling around in higher gravity than a four or two legged being. If evolution selected for tool use going to four legs and two arms might be as natural as animals going from four legs to two in our case.

[General Davis]

Huh?

 

 

 

So spiders and octopi have "8-D wiring?"

 

Seriously, are you just high right now?

 

i`m new to this but i think it would be more logical for it to have more than three legs for not only would it not be fast, depending on where the third leg would be located, it would have trouble walking let alone anything else....

 

(Please reply...)

[pioneer]

Even number of legs is still 2-D. We were talking 3 legs or an odd number of legs, with an odd number more than 1. There is a difference between a walking gait of 1 then 2, and 1,2,3. As they learn to march in their ancient days when they are still in the mythological stage, they will begin to think in terms of a three step movement not just in exterior space but also interior space. You have heard the expression logic steps. If would be hard to think in terms of a 2-D concept like good and evil because someone would say what about the middle step, when we walk through life. Our minds are used to thinking in 2-D symmetry and not 3-D symmetry.

 

It may have been easier to see with the eyes. The wiring in the brain has two paths that cross in the middle and invert. If you had a third eye you would probably still have these two paths plus a straight wiring path with all three merging and then inverting with the center path going straight to the back. The natural wiring would see 3-D plus. I other words, there are now 3 combinations of two eyes each of which can see 3-D. The brain would see 3-D from three slightly different angles. The trained mind would notice this slight difference requiring extra logic, which would begin to approach more like 3-D logic.

 

For example the cell is a highly integrated entity, which is why it is so efficient. We narrow down observation to cause and affect plus a random variable because 2-D is not enough to take into account the 3-D integration that makes it so efficient. If we look at the 3 eye example, there are three degrees of 3-D observational attachment that need to be satisfied. They could use three random degrees of attachment for the third variable, but this looks mythological. This triple random would be reduced into a third logic step.

Edited October 11, 2008 by pioneer