Stage 15 Xenopus embryo
  • Generic Explanation: A causal explanation that appeals to mechanical forces due to the geometrical arrangements of mesoscale materials, abstract properties of network organization, symmetry breaking, or irreversibility. The explanation is generic because it can apply to living and non-living phenomena.

  • Genetic Explanation: A causal explanation that appeals to changes in the frequency, distribution, or expression of genes and interactions among their RNA and protein products. The explanation is specific to living phenomena, which exhibit genetic properties.

  • Explanatory Integration: Combining or synthesizing different types of causal explanations or different kinds of causal factors into a more unified formulation, which yields an increased understanding of complex phenomena that result from a plurality of causes; often interdisciplinary in nature.

  • Development: The variety of interacting processes that generate the heterogeneous shapes, size, and structural features of an organism as it develops from embryo to adult, or more generally throughout its life cycle. Synonym: ontogeny.

  • Evolutionary Novelty: The origin of qualitatively new functional and structural variation at distinct phylogenetic junctures at different levels of hierarchical organization; ‘qualitative’ refers to a departure from the normal range of variation available in the ancestral ontogeny.

  • Evolvability: The capacity of an organismal lineage to generate selectable phenotypic variation by a variety of intrinsic and extrinsic mechanisms, such as genetic and developmental architecture or population structure.