Convergent evolution of vascular optimization in kelp (Laminariales)

Area of Science:

• * Comparative biology
• * Evolutionary biology
• * Phycology

Background:

• * Terrestrial plants and mammals exhibit conserved body plans with universal allometric scaling in vascular networks and metabolic traits.
• * This suggests an evolutionarily 'optimal' transport strategy adopted by many species.
• * Examining less-studied vascularized phyla is crucial to assess the universality of vascular optimization.

Purpose of the Study:

• * To evaluate vascular scaling and optimization in brown algae (Phaeophyceae), a distantly related group that convergently evolved plant-like body plans and transport networks.
• * To test an optimized transport anatomy model using measurements from giant kelp (Macrocystis pyrifera).
• * To assess classical allometric relationships in kelp vascular tissues across diverse species.

Main Methods:

• * Development of a model for optimized transport anatomy.
• * Measurement of vascular parameters in Macrocystis pyrifera.
• * Evaluation of allometric relationships in various kelp species (Laminariales).

Main Results:

• * Macrocystis pyrifera demonstrated strong allometric scaling relationships between vascular parameters, aligning with the developed model.
• * Other kelp species within the Laminariales order showed weak or inconsistent vascular allometries.
• * Absence of universal scaling across kelp species contrasts with the optimized anatomy found in M. pyrifera.

Conclusions:

• * The presence of optimized vascular anatomy in Macrocystis pyrifera, despite inconsistent scaling in related species, raises questions about the evolution of optimization.
• * Optimized vascular systems may confer a competitive advantage to multicellular phyla.
• * Further research is needed to understand the evolutionary pathways and benefits of vascular optimization in diverse lineages.