>This may have been the most important question raised in the discussion: is it only "speciesism" that leads us to value complex life more than "less complex" life, or is there actually a rational basis from which to ask the question of which animals' lives are more important?

I mean, "important" is a value judgement, and so the question becomes "important to whom and for what". Animals are super important to me, for instance, because they provide me with a lot of different food products. I suppose the term "specieism" is an attempt to try to draw parallels with the notion of "racism", and to transfer the current moral outrage over the latter to the former, but if you ignore the emotional elements, the parallel isn't particularly helpful.