Eukaryogenesis as a Process of DNA Packing: Review and Integration

The origin of eukaryotes represents one of the most profound unresolved questions in evolutionary biology. Although more than a dozen competing hypotheses have been put forward, no unified consensus has yet been reached. This paper critically reviews the major endosymbiotic and non-endosymbiotic theories, revealing a critical limitation shared by most existing models: the nearly 2.5-order-of-magnitude difference in genome size between prokaryotes and eukaryotes cannot be sufficiently explained by stochastic endosymbiotic events alone. I propose a new integrative framework in which eukaryogenesis is viewed as a process of subcellular structuralization driven primarily by DNA packing. This framework reconciles contradictions in current theories by clarifying the dynamic coupling between genome expansion induced by rising atmospheric oxygen and the emergence of sophisticated DNA packing mechanisms, which together supported the increase in cellular complexity, genome enlargement, and ordered biochemical processes. This study seeks to resolve long-standing controversies among competing paradigms, establish a robust theoretical framework for reconstructing eukaryogenesis, and provide critical direction for future interdisciplinary investigations.