Drift-barrier hypothesis

[1] It suggests that the perfection of the performance of a trait, in a specific environment, by natural selection will hit a hypothetical barrier.

Through natural selection and random genetic drift, the traits with a negative effect on population fitness disappear from the gene pool.

[8] In 2016, they measured transcriptional error rates in Escherichia coli as well as two endosymbiotic prokaryotes, Buchnera aphidicola and Carsonella ruddii.

Traverse and Ochman’s results showed that the transcriptional error rates between E. coli and the two endosymbionts were nearly equal even though their population sizes were very different.

Their initial prediction was that the endosymbionts would have higher transcription error rates as they were subject to a large amount of genetic drift.