THE EUKARYOTE ENDOSYMBIOTIC ORIGIN: A CONSTRUCTAL THEORY-BASED EXPLANATION

Abstract

The origin of eukaryotes is regarded as one of the most significant issues in the history of life. Various perspectives aim to provide a comprehensive understanding of eukaryote origins, drawing on paleontological evidence, energetics, the unique characteristics of eukaryotes, and the relationships between different eukaryotic groups. Several versions of the endosymbiotic theory have been proposed to explain the emergence of eukaryotes and their mitochondria. Only recently have energy and energetic constraints been integrated into this theory, recognizing that the prokaryotic cell structure played a crucial role in the development of eukaryotic complexity. Specifically, cells with mitochondria possess the bioenergetic capabilities necessary for this complexity, which explains the absence of transitional forms between prokaryotes and eukaryotes. This study explores eukaryotes' origins through the lens of constructal theory, which posits that “for a flow system to persist over time (to survive), it must evolve to facilitate easier and more efficient flow.” In this context, the theory suggests that the evolution of systems is driven by a need for optimal architecture and flow organization, reducing resistance to internal flows (exergy losses) that sustain the system. This framework is proposed as the underlying principle behind the origin of eukaryotes, mitochondria, chloroplasts, and the eukaryotic nucleus.