Problem solving in life is recognized and accepted. But how could it occur in life without intelligence? No natural process explains this. Random additions, deletions and mix ups in the genetic code do not reasonably explain how life reaches the goal of solving the many problems it faces. Problem solving is well beyond the scope of natural selection and variation. Organs, structures and systems in life, from the intricacies of the cell, to the interaction with the surrounding environment, exhibit problem solving not only for the survival of organism, but amazingly for the survival of many other organisms as well. There are hundreds of thousands of organs, structures and systems in life designed to solve specific problems. There should be no question that intelligence had to have been involved.
There is a massive amount of evidence in living things to demonstrate problem solving. Many forms of life have specialized features that are designed to solve a problem or meet a goal. My personal belief, one that is supported by the facts, is that God created life and especially man with a purpose to solve a problem, at least part of that purpose being a dwelling for the human soul, and also for the spirit of God. I don't come to that conclusion from science, because science is incapable of finding that answer. Science does however reveal the need to look beyond, to look for God.
For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse. (Romans 1:20)
If there was no excuse when this was written, when they had little understanding of biology, how much less of an excuse is it today?
One celled and some "simple" multi cellular organisms do not need any additional systems in order to carry on respiration, but once you get to organisms that have cells that are not exposed to the elements, complex integrated systems, supported by many subsystems in order for life to function. They need to access to the materials that provide energy for the cells. There also needs to be a system to get these items to the cells, and there efforts must be coordinated. Complex organisms need a respiratory system, a circulatory system and a nervous system. Simple one celled organisms reproduce by division, which in itself is very complex and precise. But more complex life uses very complex interdependent reproductive systems. All these systems must function together in order for life to work and survive. The failure of any one of these systems, and in many cases only part of the system means the death of the organism. So not only each system needs to operate correctly, but each system needs to operate with each other system; and this is no small feat. They need to be integrated and coordinated.