Rights should not be a construct of law. The very concept of human rights means that humans should be entitled to them since the first day they are born, not the case where they only have rights because the law says so. Countries which have laws encompassing human rights merely adopt them into written statutes that can be enforced; they don't create rights out of thin air. Thus, these "fundamental moral rights" should exist quite independently of law, and if the law recognises them, that is the most ideal scenario.
1) Rights are only important if they can be enforced, hence why more developed countries almost always have more "rights"
2) The ideas of rights and morality can only exist withing a social contract
3) The ideas of rights continue to change, and this change stems from the standard of living any society is living. If a society can afford to treat it's citizens with greater respect, or if those citizens are powerful enough to demand greater treatment, then they gain more rights. Outside of law or society, however, your 'rights' do not exist, as they are never in question. You have the freedom to do whatever you want.
You lose some of your freedoms when you enter a social contract, so 'rights' are the way that the individual can demand a certain treatment from their government.
Also, morality does not objectively exist, and is strictly dictated by societal norms and law. Hence, outside of society or law, there are no "fundamental moral rights."