The endosymbiosis that resulted in the harnessing of mitochondrial energy production appears to have only happened once (see work by Nick Lane) and resulted in a ~20 fold increase in available energy to the cell was followed very closely by the Cambrian explosion. We could still all still be bacteria today without it.
pdl410|1 year ago
https://nick-lane.net/wp-content/uploads/2017/05/Lane-J-Theo...
baq|1 year ago
pdl410|1 year ago