I think that Mario Vaneechoutte argues convincingly against the notion that evolution is always directed towards greater complexity.
An example that may interest him is the Australian Koala. This is a highly specialised marsupial which eats only eucalyptus leaves.
While the Koala's digestive system has evolved to extract nutrients from the highly toxic leaves its brain has shrunk to the extent that
it only occupies about one quarter of the cranial capacity. This is the type of evolution towards less complexity that Mario suggests
also occurs in parasites. It also raises some questions in respect to fitness. How can it be sustained that a reduction in brain size,
and probably intelligence, increases the organism's fitness?
The problem lies in the difficulty humans have in conceptualising systems which are non-human. All we can really say about organisms that
exist today is that they exist today. To assume that those organisms which survive are the fittest or fitter than non-surviving organisms
is to apply human societal standards to them.
Indeed, much evolutionary theory is more an insight into human and perhaps primate cognition than it is into the development or
evolution of other organisms.
I have also read much convoluted arguement by evolutionists to the effect that co-operation and aultruism are really forms of competition.
Try and convince a stockbroker that this arguement is correct and see what sort of response you get.