Roger, maybe I can add something that helps. Even while I don’t accept macro-evolution, I think I understand the theory well enough in this area of symbiosis vs competition. Part of the confusion centers around a survival of the species, vs survival of the individual. Both are part of the evolutionary theory. Survival of the individual supposes that the individual carries small barely perceptible differences compared to less “fit” individuals within the same species. This process is supposed to slowly change the dominant characteristics of the species or genotype. So for example, if an original tiger had offspring that were white and yellow, then in a snowy environment, the white tigers might survive better because they could sneak up on prey, while the yellow ones would survive better and become dominant in the wooded jungles because they could sneak up on prey better there. This could happen even if generally only 5% of the offspring were white tigers. You see the adaptation is that the yellow are eliminated due to starvation in the snow, while the white cannot get enough to eat in the jungle. Something similar would apply to white foxes vs red foxes, and white bears vs brown bears. The animals most likely to survive, are selected by their environment.
With bacteria, they do not “learn” to adapt. What happens is when a population of ecoli are in a culture that is not generally favorable, most of them die off. But there may be one or two cells that survive due to a mutation, or due to the genetic variability in the population. They may not survive as well as the others when there is oxygen, but they are the only ones to survive in anoxic conditions. They are selected by their environment. Individuals do not adapt, but the population as a whole adapts.
We can see the correlations of animals in function and color to their environment. We know this happens since we can observe it. What we cannot observe is that this process creates distinctly new species.
Not every form of natural selection would be a struggle between various species, in that I agree with you. Sometimes they are simply in the wrong location, where food or temperature are not conducive.
Symbioses is generally just an expansion of a way of acquiring food, or in some cases protection from predators. Those who live in symbiotic situations are more likely to survive again. The pilot fish that clean the sharks benefit from the sharks desire to be cleaned. Sharks that do not get cleaned get sick more often and don’t survive as long. The pilot fish who clean sharks get more food than other pilot fish who ignore this food supply. Behaviour is certainly a learned behaviour sometimes, although sometimes it is also somewhat instinctive. Or it can be taught. That is a form of adaptation as well. But again, it cannot lead to biological evolution unless there is a genetic cause or association. The fish will continue to be a fish, and its appearance will not change merely because its behaviour changes. On the other hand, evolutionists will claim that genetic changes within two species might lead to a new symbiotic behaviour that benefits both species.
Cooperation is another example of natural selection or survival of those who adapt. When wolves hunt together, they cooperate as a pack to find and bring down food. It is more likely in difficult times, that a lone wolf will not be able to bring down a large moose for supper. So cooperation enables survival. Natural selection selects against the lone wolf. In a similar way, a herd of water buffalo can defend against a pride of lions by cooperating in numbers. The lone buffalo will be conquered by the lions. So cooperation is real, but does not really change the precept of natural selection.
However, natural selection does not create new species, it only ensures the survival of some species, and usually the survival of the healthy and strong and best adapted within that species. As a general rule, it works against the survival of off-types, and against survival of new mutations, which are usually deleterious.