Experiments on the role of deleterious mutations as stepping stones in adaptive evolution
Abstract
It might seem obvious that deleterious mutations must impede evolution. However, a later mutation may interact with a deleterious predecessor, facilitating otherwise inaccessible adaptations. Although such interactions have been reported before, it is unclear whether they are rare and inconsequential or, alternatively, are important for sustaining adaptation. We studied digital organisms—computer programs that replicate and evolve—to compare adaptation in populations where deleterious mutations were disallowed with unrestricted controls. Control populations achieved higher fitness values because some deleterious mutations acted as stepping stones across otherwise impassable fitness valleys. Deleterious mutations can thus sometimes play a constructive role in adaptive evolution.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- August 2013
- DOI:
- 10.1073/pnas.1313424110
- Bibcode:
- 2013PNAS..110E3171C