Home – Home – Jornals – Contemporary Problems of Ecology 2004 number 5

Emergence of novel morphotypes of plants and animals and their relationships with evolution of ecosystems is an important problem of general biology. In the paper, the organization and evolution of gene networks of animal embryogenesis and higher plant development are considered. Similar features of these gene networks, including block-wise organization, hierarchy, and overlapping of subsystems, enable to suppose common mechanisms of rapid evolution of morphogenesis by reorganization of relations of gene networks due to mutations of not many genes being the central regulators. Contours with negative feedback are able to make the effect of such mutations "neutral", thus slowing down the evolution of morphogenesis. Disruption of such contours occurring due to changing direction of the vector of selection causes the penetration of the whole spectrum of previously "neutralized" mutations, hence, it stimulates an explosion-like emergence of novel morphotypes, which provokes the crisis of an ecosystem. In the paper, the correspondence of this scenario to paleoecological data is discussed.