<p>Cancer is one of the leading causes of global morbidity and mortality and is characterized by its high heterogeneity, genomic instability and adaptive plasticity. Applying Darwin’s theory of evolution, the concept of tumor evolution has improved our understanding of the biological behavior of advanced cancer, while technological limitations have long left how to dynamically characterize the evolutionary process unsolved. In recent years, the development of high-throughput sequencing, single-cell and spatial omics, lineage tracing, computational modeling, and noninvasive biopsy technology has helped explain tumor heterogeneity and track the evolutionary trajectory of tumors, which has attracted widespread attention in tumor evolution. Here, we discuss the models and drivers of tumor evolution, focusing on how cancer cells adapt and evolve under multidimensional selective pressure, including the intracellular, extracellular, and exogenous levels. We further summarize key signaling pathways and molecular mechanisms involved in genomic instability, epigenetic regulation, metabolic reprogramming, tumor microenvironment remodeling, immune escape and therapy-induced selection. In addition, emerging therapeutic strategies guided by tumor evolution are also discussed, emphasizing that the identification of key genetic and epigenetic targets, together with dynamic monitoring of clonal changes, is crucial for overcoming treatment resistance and improving patient outcomes. By systematically summarizing the signaling pathways and molecular mechanisms underlying tumor evolution, this review aims to provide new targets and conceptual frameworks for promoting precision treatment strategies in oncology in the future.</p>