Why the animal kingdom appears to be so brutal?
Transitional physical bodies are not important in themselves, but what they are a vehicle for: the shaping and developing of energy and the passing on of genetic material so that the process can go on. Biological evolution is necessary for the evolution of the soul. Preserving the bio-environment, so that organisms can continue to develop, is more important than self-preservation. The more primitive organisms are, the more readily they perish after reproduction. This is because there is a very limited chance for progressing while attached to a relatively simple organic form.
If there is the evolutionary intent, why are there still so many simple organisms?
Biological life is interdependent, more complex organisms cannot survive without simple ones. This does not mean that evolution is deliberately stalled in some cases. There is a constant influx of crude non-material energy that needs primitive organisms.
What is the fundamental difference between animals and humans?
Both, animals and humans, have the self and soul. So, animals are aware and self-aware (e.g. they can be aware of their own pain), but their ability to construct reality, to integrate their experiences, is very limited. They are not able to conceptualise, so any mental structure relies chiefly on the consistency of immediate physical sensations. In this respect their experience resembles a dream-state (e.g. the past, the future or reality outside their vicinity is non-existent or fragmented at best). Also, they do not have ‘I', a mental representation of themselves, so the inner and outer world are far less separated. As a consequence, they cannot distance themselves from, organise and reflect on their experiences, which means that it is unlikely that they can affect the content of their minds. Humans, on the other hand, can connect clusters of experience in much more elaborate ways because their brain size and structure is more complex (there are forms of connectivity among nerve cells not found in any animal). These connections lead to separating the internal and external further, which enables them to interpret, create and reflect upon the materials of awareness (giving rise to art, for example). However, as already mentioned (p.166), this ‘barrier' makes humans less open to more direct experience and interactions, which does not seem uncommon in the animal kingdom (see, for example, Sheldrake, 2000).