Let's assume humans have rights. Humans are a kind of animal. So it follows that some animals have rights.

So then, what is the difference(s) that qualifies some animals as having more or less rights than others?

IOW, suppose I'm an alien and randomingly beam up an animal from another planet. What characteristics (if any) allow it to be "probed"?

Intelligence or level of conciousness would seem to be the most common indicator.

Higher primates, dolphins, octopuses, and various other smart animals seem to get more rights then others.

Well, first of all it does not follow. Cats have tails. Cats are a kind of animal. Does it follow that all animals have tails? Certainly not.

Anyway, humans tend to value the rights of those creatures that are more like to them, especially when it comes to the brain and mind. Monkeys are more similar to humans than cats, so we tend to respect monkey rights more than feline rights. Cats are more like us than lizards, so we respect cats more than lizards. Lizards are more like us than fish, so we respect lizards more than fish. Fish are more like us than bugs, so we respect fish more than bugs.

All of this has a very obvious evolutionary explanation: all creatures endeavor to preserve their own genes, and the more an animal is like us, the more we should desire to preserve its genes. Unfortunately, that is also the cause of problems like racism.

As for animals from other planets... this truly is an interesting question. Genetically speaking, they are probably going to be less like us than even fish, but people don't actually base their judgment on genes but rather through evolutionary circumstances. Since there have never been alien life forms on Earth throughout our evolutionary history, we cannot think in terms of similarity/differences (we are not 'designed' for it, so to speak). Instead, it is likely that a human will look at an alien creature and say 'This creature appears to be very intelligent; it has culture and science. This makes this creature more like us than cats, and so it should have more rights.' Biologically, it makes no sense, but this is a likely reasoning.

Faulty logic: A valid in set S => for a subset of S A is valid. Not the other way around!

Regardless, i do think animals have some rights. In the thread "What are your axioms" I considered a ethical axiom that claimed that the ultimate goal should be increasing feel-good of all creatures weighted by something.
One question with that is then what those weighs are. We could try equating it to consciousness, but then, what is that? I guess that what we associate combined with what creatures do with given freedom is the only measure we have available. There might be some relation with size of nervous system but i have no idea if that is usable.

@Ilya i agree that we tend to respect similar creatures more, but that it is an aspect of evolution i doubt. Psychology i think. I also think that in a sense, what we naturally associate is all we have as a judge. We also naturally respect larger creatures more.
Maybe it can help, trying to study creatures more, to find analogies with creatures we have positive associations with? Then we bump those creatures up the 'respectability' or 'weighs', to a level closer to what is deserved. Many sea creatures may have to be respected more.

Also even if we respect a certain creature: What rights does it get. Some creatures have different needs then others.
PS hadnt seen your post writing my previous post

Hit the nail on the head.

To the alien question, considering aliens even using DNA as their genetic base is speculation at best, they are likely based purely on your evolutionary explanation (which while it correlates with the trend generally I don't think is the basis for it, octopuses for example arent close to us at all but are considered intelligent, and IIRC require sedation for any medical/scientific tests, rats are pretty close to us, but I'm sure some fish get treated better!), to not give a crap who or what they probe, though id dare say they'd try and hide it from humans if they don't want to be found, as we are probably the only species that could easily conceptualise the idea of extraterrestrial life. I wouldn't blame them personally, if we find reasonably smart aliens, I'm sure our scientists would be banging on the doors of their morgues begging to do autopsies!

But yeah, the less like a human you are, the worse you get it, sucks to be any kind of bacteria or virus that doesnt benefit mankind

You're right to say that the reasons are psychological, but don't forget that even psychological reasons originate from evolution.

agreed.

i also think that our ethic is influenced by our needs ... if starvation was an issue for everybody, it would be morally accepted to kill and eat every animal that crosses our path. on the other hand, the less we depend on animals to survive, the more room there will be for the concept of animal rights to gain ground.

Bolding mine.

Actually, his logic is just fine. If he had claimed that since some animals have rights, then they all do, that would have been faulty logic. But he did not claim that. What he claimed is supported logically. I'm guessing some people overlooked the word 'some'.

@bns, guess i missed that word.
@Ilya: Of course thought about evolution causing psychology. I was not sure about it, for one to say evolution had a role it in one must consider where in natural selection it is advantageous. As individuals, it might be advantageous in recognizing parents, but that is only a single layer. Respecting whole other species it not useful for that. As species-selection, i doubt that one species actively helps another, so similarity-respect in that selection helps very little. Then there is the hurding behavior or different animals. Problem with that that we also respect predators. My conclusion is that the cause is not evolution, at least not in those simple ways.

Getting back to topic: Can we get more general ways of determining rights and importance thereof? The only ones i can think of is seeing what they do when given oppertunities, what we naturally associate, and making analogies with that. And when we get to trying to define rights/weights of specific animals what kind of things should we talk about?

In natural selection, the gene is the unit that is selected, not the species.

I dont get what you mean. Genes are not selected, the different organisms are.(at least that is one abstraction of it) There is species selection in the way that, some adaptations might benefit the individuals, but are very destructive for its relative close cousins, like its species. That can cause the species to go extinct. (hence species-selection) Probably this kind of selection can be very strong in species like bacteria.
This thread is not about evolution, though, and i am not a expert on that either. The above is just what i passer-by read combined with some logic.

yes, we're getting off-topic ... this is what i was refering to:
Gene-centered view of evolution - Wikipedia, the free encyclopedia

Using genotype to determine rights is a little counterintuitive when actually put into practice. For example, IIRC most animals share at least 90% of the same genes as humans.

Do we conclude that all animals have 90% of the same rights as humans? Or do we reject genes as a basis of rights?

Hmmm.. this article is relevant:
CNN.com - Mice, men share 99 percent of genes - Dec. 4, 2002

Did anyone suggest that genes is actually a good basis for assigning rights and importance to a creature? We just discussed the (lack of)evolutionary origin of our respect for animals. I think we are still at the question i posed at #10. Are there any more general aspects of creatures to take into account? Also any of the implicit ones, i would like to know. If we can not make any more general statements, there is little else to do then consider/compare specific animals.

For instance if you could save either a cow or a cat from death(with no other effect), which would you save? (Please consider more the more general statements first, I think we are short on those.)

It's completely unethical for us to say that something with severe mental retardation has less rights unless they are doing some harm, so I don't know why you guys are using intelligence as a factor on how important any given animal is.

It follows the kind of pseudo-vegetarianism I have seen too much of "omg chickens can feel pain, I will never eat chicken again". Yet they'll happily consume a yoghurt coloured with crushed insects.

Most people are very afraid to look into animal rights for fear that they're wrong. My personal stance is that any justification put forward for hurting animals is flawed.

I agree with you on that, sometimes I wish people that make fun of retarted people would end up the same way so they can see how it feels. I know it sounds mean.

I don't really think it has anything to do with intelligence, but more about emotion. "Rights" are a human creation. If I ran into a hungry cougar in the woods (as in the big cat, not the human kind) who decided that I would be a good meal, it is doubtful that the cougar would stop to think about my rights. Humans, on the other hand, are driven by emotion in almost all that we do, and it would appear that we are the only animals who care about the rights of other animals.

I don't think it would be an intellectual decision if a human had to save a cow or a cat. I associate cats with my childhood, so I feel strongly about them. I don't really have any emotional connection with cows, so I would probably save the cat.

You're looking at rights in the wrong way. Rights are just freedoms which haven't been restricted yet. Before government, we had theoretically infinite rights. The same applies to animal rights. It's understandable that in past years we wouldn't have faired to well without killing animals. Through culture, this has degraded the rights of animals.

To get a logical consensus you need to blot out our "i love my meat" culture, and your past emotions on the matter, and look into human nature. Culture, such as circuses and the meat industry, is not a good excuse for taking rights. Neither is your experience with cats a good reason to give rights to cats.

I never said it was a good reason, I just think that it IS the reason. Emotion might not be a good reason to start a war, or commit suicide, or murder... but it very often is a reason.