Originally Posted by Xurtio

Many "lower" life forms probably don't have suffering, just avoidance responses. That is, there's likely not a consciousness associated with simple lifeforms, especially the ones without a brain. The structures associated with consciousness probably didn't come about until after chordates. So we already have a universe in which suffering wasn't necessary for life. Consciousness, and the suffering that comes with it, could just be a biological spandrel.