Genes are just buffs, regardless of how little sense it makes.
Genes that change a part of the body don't actually change a part of that body. (new body parts should be added or existing body parts changed from genes)
Buffs tied to a body part don't go away when you loose that part of the body. (got your hand shot off? the long-fingers buff was tied to that new/changed body part, so now you lose half of the bonus)
The implementation is just shoddy.
Genes that change a part of the body don't actually change a part of that body. (new body parts should be added or existing body parts changed from genes)
Buffs tied to a body part don't go away when you loose that part of the body. (got your hand shot off? the long-fingers buff was tied to that new/changed body part, so now you lose half of the bonus)
The implementation is just shoddy.