[geor9e]

devolution (n) - (word sense #2) retrograde evolution, degeneration (https://www.merriam-webster.com/dictionary/devolution)

de-evolution & deevolution aren't words https://www.merriam-webster.com/dictionary/de-evolution

[torstenvl]

https://en.m.wikipedia.org/wiki/Morphological_derivation

https://www.merriam-webster.com/dictionary/de-

[geor9e]

Sure, but it's one of English's specific exceptions to the rule. De-evolution should be spelled with one e, in-flammable actually means flammable, etc