Which concept emphasizes the combined action of multiple mechanisms of change in evolution?

The concept that emphasizes the combined action of multiple mechanisms of change in evolution is evolutionary synthesis. This framework integrates various ideas from genetic, ecological, and paleontological perspectives to explain how evolutionary processes operate. The evolutionary synthesis combines Darwin's theory of natural selection with Mendelian genetics, highlighting that evolution is not driven by a single mechanism but rather through a complex interplay of factors such as mutation, migration, natural selection, drift, and gene flow. This comprehensive approach allows for a more nuanced understanding of how species evolve over time, accounting for variations in populations and their interactions with the environment.

In contrast, niche construction focuses on how organisms modify their environment and consequently affect their own evolution, but it does not encapsulate the broader range of evolutionary mechanisms. Neutral theory primarily addresses the role of genetic drift and mutation in evolution, suggesting that much of the genetic variation seen in populations is due to random processes rather than natural selection. Adaptive radiation refers to the diversification of a group of organisms into forms filling different ecological niches, which is a result of the interaction of evolutionary processes but not a concept that combines all mechanisms of change comprehensively. Thus, evolutionary synthesis is the most inclusive concept in capturing the complexities of evolutionary change.