Is the value of a life proportional to its level of consciousness?

The value of a life is often considered proportional to its capacity to feel, think, and be self-aware. As such, animals are often treated with less value than humans, as are embryos with less value than adults. However, some religious thinkers believe that these factors are inconsequential - all that matters is that the life is a human one, and that it is uniformly valuable regardless of its development or deterioration, providing ground to their opposition to abortion and euthanasia.