Macroevolution, differentiation trees, and the growth of coding systems

An open process of evolution of multicellular organisms is based on the rearrangement and growth of the program of differentiation that underlies biological morphogenesis. The maintenance of the final (adult) stable nonequilibrium state (stasis) of a developmental system determines the direction of the evolutionary process. This state is achieved via the sequence of differentiation events representable as differentiation trees. A special type of morphogenetic code, acting as a metacode governing gene expression, may include electromechanical signals appearing as differentiation waves. The excessive energy due to the incorporation of mitochondria in eukaryotic cells resulted not only in more active metabolism but also in establishing the differentiation code for interconnecting cells and forming tissues, which fueled the evolutionary process. The invention of continuing differentiation distinguishes multicellular eukaryotes from other organisms. The Janus-faced control, involving both top-down control by differentiation waves and bottom-up control via the mechanical consequences of cell differentiations, underlies the process of morphogenesis and results in the achievement of functional stable final states. Duplications of branches of the differentiation tree may be the basis for continuing differentiation and macroevolution, analogous to gene duplication permitting divergence of genes. Metamorphoses, if they are proven to be fusions of disparate species, may be classified according to the topology of fusions of two differentiation trees. In the process of unfolding of morphogenetic structures, microevolution can be defined as changes of the differentiation tree that preserve topology of the tree, while macroevolution represents any change that alters the topology of the differentiation tree.

Automated summary

The open process of evolution in multicellular organisms is driven by the rearrangement and growth of the differentiation program. The final stable state of a developmental system determines the direction of evolution and is achieved through a series of differentiation events represented as differentiation trees. Electromechanical signals, acting as a morphogenetic code, play a role in gene expression and contribute to the evolutionary process. The incorporation of mitochondria in eukaryotic cells led to active metabolism and the establishment of a differentiation code, fueling evolution. The invention of continuing differentiation distinguishes multicellular eukaryotes from other organisms. Control mechanisms involving differentiation waves and mechanical consequences of cell differentiations are instrumental in morphogenesis and the achievement of functional stable states. Duplications of differentiation tree branches serve as the basis for continuing differentiation and macroevolution.