New research challenges the simple narrative of eukaryotic cell evolution, revealing that the first complex cells acquired genes through multiple waves of bacterial gene transfers rather than a single fusion event between bacteria and archaea. While the endosymbiotic origin of mitochondria remains valid, the study shows that gene transfers from various bacterial sources were more extensive than previously thought. This finding provides a more nuanced understanding of early eukaryotic evolution and the complex genetic mosaic that makes up modern complex cells.
Background
The prevailing theory of eukaryotic cell origin, known as endosymbiotic theory, proposes that complex cells evolved from a single fusion event between an archaeal host cell and an alphaproteobacterium that became the mitochondrion. This theory has been widely accepted but continues to be refined with new genomic evidence.
- Source
- Ars Technica
- Published
- Jun 11, 2026 at 08:44 PM
- Score
- 7.0 / 10