Patterning, From Conifers to Consciousness: Turing's Theory and Order From Fluctuations

Area of Science:

• Developmental biology
• Theoretical biology
• Mathematical biology

Background:

• Alan Turing's seminal work proposed a mechanism for biological pattern formation.
• Periodic patterns, particularly 2D arrays of oriented stripes, have been central to understanding these theories.
• The concept of 'order from fluctuations' is fundamental, suggesting pattern arises from amplified random molecular or cellular processes.

Purpose of the Study:

• To review Turing's ideas on biological pattern formation and their acceptance in biology.
• To explore the role of theory in biological investigations.
• To discuss the applicability of Turing's concepts to complex systems like brain development.

Main Methods:

• Analysis of Turing's theoretical framework for pattern generation.
• Comparison of theoretical predictions with biological examples, including Drosophila segmentation, fish skin patterns, and chemical reactions.
• Examination of the timescales of fluctuations and selection processes in different biological systems.

Main Results:

• Turing's theory successfully explains patterns in fish skin and chemical reactions, termed 'elegant' examples.
• Drosophila segmentation, considered 'inelegant,' is better described as a programmatic assembly process occurring over evolutionary time.
• The theory's core concept of 'order from fluctuations' involves selective amplification of spatial components from random disorder.

Conclusions:

• Turing's theory provides a powerful framework for understanding biological pattern formation, particularly when fluctuations and selection occur in real-time.
• Distinguishing between 'elegant' (real-time) and 'inelegant' (evolutionary time) pattern formation is crucial for applying the theory.
• Neuroscience, particularly brain development and consciousness, represents a promising frontier for the extension and application of Turing's groundbreaking ideas.