Problems do not naturally produce solutions. Solutions are a result of intelligence. Therefore one of the best evidences for the intelligent design of life is that life is problem solving. Problems solving is the ability to utilize and or go beyond the natural tendencies of something to find a solution to a perceived problem.

Problems are also the result of intelligence. That is, problems don't exist unless there is a goal that needs to be met. Goals are established by a perceived need, or want. Both perception and desire are traits of intelligence. A rock has no wants or needs; therefore it has no problems needing solutions.

A man trying to get across a river would not have a problem if there was a bridge for him to cross, but if there is no bridge then he has a problem, because he cannot meet his goal. The solution, build a bridge. A bridge is the obvious result of intelligence. What we forget or may not recognize is that the problem is the result of intelligence as well. When an anthropologist digs up what he believes to be a stone tool he concludes that it is the result of intelligence. The tool exists to solve a problem and the problem exists because intelligence perceived a need or a want and developed a solution.

Simply put, both problems and solutions are the products of intelligence. If there is no problem, then no solution will be sought. And if there is no intelligence, no problem will be perceived. Part of our mindset has been programmed to believe that problems and solutions can have non-intelligent origins. This idea originates with and permeates evolutionary theories of development. While natural solutions may present themselves the recognition and use of them requires intelligence. Take for instance a fallen tree and a bridge. The bridge is an obvious solution to the problem of crossing a river. A fallen tree however is not caused because of the need to cross a river, but through natural processes of decay or wind. Both the tree and the bridge offer a solution to crossing the river, one has a natural cause and the other has an intelligent cause. But only intelligence will use the tree as a solution for the problem of crossing the river.

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.

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 they need 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 (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.

There is still more to the complexity and interdependency of life. The diversity of organisms is a necessity to the ecosystem. The requirement of diversity means that multiple solutions to each of the problems life needs to solve for each organism are necessary to maintain an ecosystem. There is diversity within species, but there is also a diversity that is outside the organisms themselves. For instance: bees and flowers or air for plants and animals.  "Biodiversity" is a level of organization and problem solving that exists outside the organism, yet is also part of the design of the organism. Hummingbirds are designed with flowers in mind, the flowers are designed with hummingbirds in mind.  Ecosystems need a variety of life to be maintained. Each organism provides a "service" to the ecological community, such as pollenization. Without the provision of the services by one or more organisms the ecosystem fails and multiple organisms die. There are multiple ways of providing the same service through the activities of sometimes many different organisms. A needed ecological service presents a problem and the design of an organism to provide the service provides the solution.

The diversity of life is a necessity for life to continue, for if the design of all life were after the same resources life could not flourish. The diversity of life is a prime example of problem solving. For each type of needed activity in life, be it respiration, circulation, stimulus response, or reproduction there are multiple solutions to be found. And these multiple solutions we have found to be a necessary part of solving the problems that life faces.

All life is essentially built on the same framework, DNA, RNA, proteins, enzymes.  This is necessary for compatibility between organisms and allows for a great diversity. A very basic goal of life, the only one that science can recognize is survival. Yet, even the goal to survive is an intelligent goal, that is, survival is not necessary unless there is a purpose for existence. Without a purpose for existence there is no reason for survival. Without an intelligent goal beneficial features have no reason to exist. Nature does not know the difference between a good and a bad idea. Chemicals and sub atomic particles do not have the ability to say "hey, we need a new feature."  Chemicals don't care, they have no goals. The problem of survival and the solutions to survival on both the biological and ecological levels have been engineered by intelligence.
The information to build and coordinate all the structures in life is coded on information bearing molecules in each cell. No human engineer has yet to fully comprehend how this is done nor is able to improve on its design.
Life is far too precise and goal orientated to have been assembled by the error of mutation and the trial of natural selection. Life shows the intelligent perception of problems and intelligently designed solutions.