Origin of the Eukaryotic Cell

Nick Lane Molecular Frontiers Journal Mol. Front. J., 01, 108 (2017)

All complex life on Earth is composed of ‘eukaryotic’ cells. Eukaryotes arose just once in 4 billion years, via an endosymbiosis — bacteria entered a simple host cell, evolving into mitochondria, the ‘powerhouses’ of complex cells. Mitochondria lost most of their genes, retaining only those needed for respiration, giving eukaryotes ‘multi-bacterial’ power without the costs of maintaining thousands of complete bacterial genomes. These energy savings supported a substantial expansion in nuclear genome size, and far more protein synthesis from each gene.

Keywords : Eukaryotes; Mitochondria; Bacteria; Energy per Gene; Complexity.