Intelligent Input and Evolution

No one who has looked at the evidence objectively can deny that humans have evolved. They have evolved culturally, morphologically and technologically in the time they have been on the earth. In addition, our kinship with our other primate cousins is clear. That all primates most likely had a common origin is obvious.
What is not obvious, however, is the mechanism by which these changes have occurred. In this matter we are still pretty much in the dark. Evolution is a process, that is strongly supported by empirical evidence. But it remains a process looking for a believable mechanism. Random mutation and natural selection are mechanisms of evolution and it is possible to accept the reality of evolution on a scientific basis and deny the claim that mutation and natural selection are capable of achieving it.
Intelligent input is also a mechanism of evolution, without any empirical support. But it is clearly obvious to me that random mutation and natural selection are insufficient to explain the complex systems that human beings possess as well as the cultural, intellectual and social components of our collective humanity.
What we observe in humans (and other living systems) are means adapted to ends. We see structures supporting other structures and we see processes supporting other processes. We also see that these structures and processes are integrated into functional systems in such a way that they all support the overall function of the organism.
Science has failed to establish with empirical evidence, any kind of believable link between the trivial effects of mutation and selection and the emergence of highly organized structures, processes and systems. Some important component is missing.
It seems to me that such a level of organization simply cannot be achieved by random processes and requires insight. Some kind of intelligent input seems necessary.