The innovation triad: an EvoDevo agenda

Area of Science:

• Evolutionary biology
• Developmental biology (EvoDevo)

Background:

• Evolutionary innovation and morphological novelty are increasingly important research areas.
• Distinguishing these from standard evolutionary concepts like variation and adaptation is crucial.

Purpose of the Study:

• To propose a conceptual framework, the "innovation triad" (origination, innovation, novelty), for studying morphological evolution.
• To delineate a research agenda for the innovation triad, separating initiating conditions from mechanistic realization.
• To discuss theoretical challenges in treating innovation distinctly from variation.

Main Methods:

• Categorization of empirical approaches into four research strands: morphology and systematics, gene regulation, epigenetics, and theoretical biology.
• Analysis of theoretical problems arising from separating innovation from variation.
• Review of contributions within the special issue to exemplify research programs.

Main Results:

• The innovation triad provides a distinct conceptual complex for addressing evolutionary innovation and morphological novelty.
• Four major research programs empirically investigate the innovation triad.
• The innovation triad is a defining topic in EvoDevo research.

Conclusions:

• The innovation triad offers a significant contribution to evolutionary theory by focusing on internal developmental dynamics.
• Incorporating developmental systems properties shifts emphasis from natural selection to internal system dynamics.
• This approach complements adaptation with emergence and contingency with inherency.