Body architecture versus Earth's history and extinction

The text analyzes mass extinctions not as a simple impoverishment of the biosphere, but as key evolutionary operators that drastically change the hierarchy of biological opportunities. The author discusses the transition from qualitative catastrophism to quantitative paleobiology, citing the works of Newell, Sepkoski, and Raup. Particular attention is paid to the concept of the 'Big Five'—the five strongest extinction peaks in the Phanerozoic, including the Cretaceous-Paleogene boundary. The analysis points to the lack of a single universal cause for these crises; ranging from glaciations and oceanic anoxia to the influence of land plants and volcanism. Mass extinctions act selectively, promoting previously secondary traits, which leads to a complete restructuring of ecosystems and the emergence of new dominant groups of organisms.