Yes, like in the past you could kill other people and such. Just make sure you are strong enough to kill anyone in the way. I sure miss those days.
Quite frankly, we traded rights with duties, we got the right not to be harmed, in exchange of the duty not to harm others. (and sending resources for police and court) We got the right for food and shelter in trade for sending resources if possible. With this we also got the responsibility to make sure government is governed fairly. Which people in many countries fail miserably in, and i think that is why you see them as merely restricting your freedom. Edit: they are a human creation, of course.
I disagree, the mentally retarded might very well have decreased rights.(Although the rate rights go down with retardedness is not that high IMO) I would not let them have children or anything. Not allowing for them to have different rights goes against my creature based rights, i consider it racism. (A mob would have a bad time deciding rights though.)

I agree that rights/importance are subjective, claiming that all humans should have the same rights seems to be an extremists point of view. I would rather say that responsive communicative humans all have nearly the same rights/importance as far as i can tell, and i would be very self-assured to level of ridiculousness if i did not think so. Non-communicative humans i think i can assign less rights like not thinking they are capable of rearing children, but also to consider them incapable of education to an extend. (indeed there would be no tests)

I would chose the cat above the cow in importance, because cats are clearly more active and communicative. While cows do not exactly have this property. I consider that cats may be more likely to solve problems that get in the way of something they want. Here i used association and analogy, i guess it is very subjective.

Maybe communicativeness should be added to the list that helps find rights/importance. Note that i am very unsure about this, but i can not reasonably give insects the same rights/importance as mammals, i think they have very little importance.(well, most insects) And there is no clear distinction when along the line between insects, mammals, fish what rights/importance is to be given.
I think rights should be part of society, and i can not consider making the rights of humans level and that of animals zero either.

I think we're getting onto a whole different ball game here. It's a very sticky issue, and one I haven't given a great deal of thought on. For the sake of keeping OT, I'ma leave it.

Mostly it comes down to culture (IMHO). The first is that since pre-historic times, we've come a long way, but we haven't evolved much. That's more a cultural evolution. If you look at the world now compared to what we had, say, 1000 years ago (in europe), we've come a long way. This involves shunning old truths and realising new ones. Perhaps one of the older, and most important ones is this: It is completely impractically and nigh impossible to not eat meat to survive.

Certainly, this was true. I know animal rights and vegetarianism are different matters, but they both follow the same arguments. As I previously mentioned, most of our lack-of-respect for animals is due to their uses, primarily in the food industry.

If, for a moment, we blotted out our past preconceptions on what we should eat, and we stand in a field with a bush of berries and two cows, what would you kill and eat? It may not be the most beautiful, huggable and friendly creature, but a cow feels pain and sadness. I don't know a single person who, with a clear mind, would take a knife to the cow, given the option of something just as good.

Oh, and I know berries don't contain the same stuff as meat. It's not an issue, if you look into a vegeatarian/vegan diet.

In my opinion, the only thing that keeps us eating dead animal is that we eat dead animal. It then comes down to your opinion on whether animals should die to uphold unnecessary traditional values.

Animal rights follows this. If people started caring that what they eat once had a curly tail we'd pay a lot more attention to the drug companies who drip chemicals in chimpanzes' eyes.

There is a flaw in your logic. The original argument was that similarity (genetic or behavioral) is correlated to caring, and rights. Never was the argument made that 1% similarity implies 1% rights, and 42% similarity implies 42% rights. But it's true that 1% similarity implies less rights than 2% similarity. The function itself probably isn't even linear!

Moreover, if the method for judging similarity is more behavioral then genetic, genes don't even have anything to do with it. If a creature acts more like a human, we care about it more, regardless of how far away from us it is on the genetic tree. For example, we probably have more in common with rats than cats, because our common ancestor with both was a small rodent, nothing like a feline. Regardless, both humans and cats have evolved from that stage to the point that we find ourselves behaviorally more similar to each other than our ancestor.

Yes, that's a valid point ... it was a simplification for the sake of argument.

The general assumption I'm rejecting is that there's any correlation between genes and rights.

For example, if mice have a 99% genetic similarity, whereas a chimp only has 97% similarity, it would follow a mouse would have more rights than a chimp.

This is not plausible, therefore there's no correlation between rights and genes. (I think we are agreeing on this point)

Actually, chimps are more genetically similar to men (nearly 100%) than mice because we've shared a common ancestor in more recent times (whereas our common ancestor with mice lived pretty much during the time of the dinosaurs). This actually is the reason why we value the rights of chimps more than those of mice.

I don't quite agree with you about this lack of correlation: there certainly is at least a weak correlation, and it's possible that it's stronger. However, I agree that it's possible that the reasons are primarily behavioral (we seek to preserve that which acts, or looks like ourselves). But then, behavioral reasons really are just a simplification of the genetic reason: people have no natural way of sensing the genetic composition of other species, so they have evolved to use the closest approximation, and that is observing appearance and behavior of species and acting based on the assumption that those species that act more like us in fact are genetically closer to us than those that don't.

Are we talking about genes as a way of identifying rights? That sounds like a crazy idea to think that is reasonable. Genes being similar as causing why we respect things is not crazy, but what mechanism would you say causes that? Beyond recognizing mom/dad? I could not find any good reason why respect of other creatures would lie in evolution. (as i said in #10) That was considered off topic, btw, maybe we should talk about what is ethical with animals rather then how evolution somehow affected that

Not as an absolute way of determining rights (if it was, it would be justification for racism), but seeing it this way helps somewhat. For example, one could ask 'why should I respect a cat more than a bug?' and the answer would be 'the cat is genetically more similar to you, so it is your nature to respect it more'.

Are you kidding? Preserving creatures that are more similar to yourself is how evolution works. What if, for instance, all of the human race was wiped off the face of the Earth. Would you, biologically speaking, prefer the Earth to be repopulated by apes, or by rats? The obvious answer would be apes, because you, as a human, want the future to have the closest thing to yourself in it. Objectively, it's just as 'good' for the Earth to be populated by rats, lizards, fish, bacteria... or even nothing at all. But living things don't see the world objectively. The very thing that makes a thing living is its subjective desire to preserve that which is closest to itself.

It's true that we are getting somewhat off topic here, but the original question was 'if some animals get to have rights, how do we determine which?' There is no objective answer to this question! If you claim that all animals should be equally respected, then we can't live our lives at all: even collecting fruits and vegetables involves the suffering of some animals.

because genes "whose phenotypic effects successfully promote their own propagation" are bound to become more ubiquitous than other genes.

a gene whose phenotypic effects would only promote its propagation in your close relatives or even species, would be at a disadvantage against a gene whose phenotypic effects would promote its propagation in every organism that exhibits the same phenotypic effects.

that is the reason we have those genes in the first place.
that is the reason we tend to favor creatures with similar traits while it wouldn't make sense if we were to look at evolution as species selection.

I still think that humans respecting similar creatures not really stems from evolution.(but rather psychology) When we respect creatures like that, we do not do that at the same level other creatures do, most of our evolutions past we could not respect them in that sense, because our brains were not developed.

To think some aspect of a creature is the way it is because of evolution does not only require it to be positive for the genotype. There must also be a way that the selective process that advantages that genotype. Respecting similar creature would require a selective process on a set of creatures so large that it can not really be taken as causal.
(btw do not feel like i am clear enough here)