title: General discussion.
mesh_terms: D005075:Biological Evolution; D005057:Eukaryotic Cells / Q000166:cytology* / Q000378:metabolism*; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D015388:Organelles / Q000378:metabolism; D013559:Symbiosis; D013997:Time Factors