An evolutionary perspective on the systems of adaptive immunity

Area of Science:

• Evolutionary biology
• Immunology
• Systems biology

Background:

• Adaptive immunity varies across life's domains.
• Existing classifications lack an evolutionary perspective.
• Understanding immune system evolution is crucial for complexity.

Purpose of the Study:

• Propose a function-based classification for diverse immune systems.
• Characterize adaptive immunity through an evolutionary lens.
• Investigate the origin and significance of Darwinian immunity.

Main Methods:

• Comparative analysis of immune system information acquisition.
• Evolutionary framework integrating Darwinian, Lamarckian, and shotgun models.
• Hypothesizing evolutionary transitions and genomic events.

Main Results:

• Introduced a novel classification: Darwinian, Lamarckian, and shotgun immunity.
• Darwinian immunity represents a major evolutionary transition, enhancing individuality and complexity.
• Proposed a 'Big Bang' origin for vertebrate Darwinian immunity driven by regulatory circuitry and genomic duplications.

Conclusions:

• Darwinian immunity is a radical innovation, re-inventing natural selection and enabling vast information storage.
• Its origin signifies a transition in individuality and a new information system, hallmarks of major evolutionary transitions.
• The evolution of vertebrate immunity was likely a rare event, dependent on specific regulatory innovations.