Fixes genetics gene changes not working (#16035)

code/game/dna/dna2_domutcheck.dm

@@ -3,7 +3,8 @@
 // M: Mob to mess with
 // flags: See below, bitfield.
 /proc/domutcheck(mob/living/M, flags = 0)
-	for(var/datum/mutation/mutation in GLOB.dna_mutations)
+	for(var/mutation_type in GLOB.dna_mutations)
+		var/datum/mutation/mutation = GLOB.dna_mutations[mutation_type]
 		if(!M || !M.dna)
 			return
 		if(!mutation.block)

code/game/dna/mutations/_mutations.dm

@@ -31,6 +31,7 @@
 
 // Called when the gene activates.  Do your magic here.
 /datum/mutation/proc/activate(mob/living/M)
+	SHOULD_CALL_PARENT(TRUE)
 	M.gene_stability -= instability
 	M.active_mutations |= type // |= is probably not required but just in case
 	for(var/thing in traits_to_add)
@@ -43,6 +44,7 @@
 // Called when the gene deactivates.  Undo your magic here.
 // Only called when the block is deactivated.
 /datum/mutation/proc/deactivate(mob/living/M)
+	SHOULD_CALL_PARENT(TRUE)
 	M.gene_stability += instability
 	M.active_mutations -= type
 	for(var/thing in traits_to_add)

code/game/dna/mutations/monkey.dm

@@ -9,6 +9,7 @@
 	return ishuman(M)
 
 /datum/mutation/monkey/activate(mob/living/carbon/human/H)
+	..()
 	if(!istype(H))
 		return
 	if(issmall(H))
@@ -42,6 +43,7 @@
 	return H
 
 /datum/mutation/monkey/deactivate(mob/living/carbon/human/H)
+	..()
 	if(!istype(H))
 		return
 	if(!issmall(H))