Perhaps a chain of loop-de-loops would be a better mental image: a series of circles rather than just the one. If the importance of any life is justified by its relation to other lives that are themselves justified by other lives, you end up with no core importance. There's no meat inside the loops.

I don't have a definite answer to your question but looking at most of what has happened in history I do wonder if developing opposable thumbs and a frontal cortex was worth it.