This study is a long-overdue attempt to tackle the complexity of evolutionary problems by mutually complementary conceptual approaches rather than from the standpoint of a single dominating evolutionary hypothesis. As a first step, I identify the major problems preventing a clear understanding of evolutionary mechanisms. They are associated with three “uncertainties” accompanying the analysis of evolutionary phenomena: (1) Terminological ambiguity, bordering on a logical inconsistency, in the construction of evolutionary concepts, (2) The uncertainty of direct observation, associated with the difficulties of documenting the evolutionary process and (3) The uncertainty of applicability, arising from the complex multilevel nature of the living matter. Then I outline a fairly substantial approach to the consideration of living systems. The analysis of the uncertainty of applicability suggests that the most productive approach is to apply the notion of an “evolving system” to systems of the organismic rank, understood as an object–process or a morphoprocess. Such systems (highly integrated metastable structures–processes) are dissipative structures with a cyclic character of implementation. Once we have identified the evolving system, we can determine three different conceptual models of transformism of these structures. Importantly, the delimitation is based on a unique set of their characters rather than an affiliation with a particular historic scientific tradition. These models of microevolution are indirect adaptogenesis, direct adaptogenesis and constructional transformism. The logic of each of them has often been used in various evolutionary concepts in the course of the last two centuries. Finally, I present a general outlook on the diversity of mechanisms of transformism. They fall into two groups: combinatory mechanisms (transformation through combinations) and transformational mechanisms as such (transformation without combination). It is the transformational mechanisms that are encompassed by the three conceptual models mentioned above. It is becoming evident that the evolutionary process is based on mechanisms described by different models. A time has come for a careful examination of various transformistic possibilities and the identification of prevailing and accessory mechanisms. Different groups of organisms/types of morphoprocesses may be characterized by different leading mechanisms of transformism, which may belong to both “combinational” and “transformational” phenomena. We have to consider a broad kit of potential evolutionary tools and try to comprehend evolutionary phenomena at a new level of conceptual synthesis.