diff --git a/hamazaki1990/individual.py b/hamazaki1990/individual.py
index b1ee698..36d06f6 100644
--- a/hamazaki1990/individual.py
+++ b/hamazaki1990/individual.py
@@ -1,10 +1,12 @@
-from decimal import Decimal
+import random
 
 
 class Individual:
-    def __init__(self, n, f=1.0):
+    def __init__(self, n, f=1.0, mutationrate=0.0):
         self._id = n
         self._fitness = f
+        self._genotype = []
+        self._mutationrate = mutationrate
 
     def get_id(self):
         return self._id
@@ -12,9 +14,20 @@ def get_id(self):
     def get_fitness(self):
         return self._fitness
 
+    def get_genotype(self):
+        return self._genotype
+
+    def acquire_mutation(self):
+        r = random.random()
+        next_genotype = self._genotype
+        if self._mutationrate > r:
+            next_genotype.append(random.random())
+        self._genotype = next_genotype
+
     def __repr__(self):
         return str(self._id)
-        return Decimal(self._fitness)
+        return str(self._fitness)
+        return str(self._genotype)
 
 
 def main():
@@ -22,6 +35,25 @@ def main():
     print(ind.get_id())
     print(ind.get_fitness())
 
+    ind2 = Individual(30, 0.8, 1.0)
+    print(ind2.get_id())
+    print(ind2.get_fitness())
+    ind2.acquire_mutation()
+    print(ind2.get_genotype())
+    ind2.acquire_mutation()
+    print(ind2.get_genotype())
+    print(ind2.get_id())
+    print(ind2.get_fitness())
+
+    ind3 = Individual(0, 1.0, 0.8)
+    ind4 = Individual(1, 1.0, 0.8)
+    pop = [ind3, ind4]
+    print([x.get_genotype() for x in pop])
+    [x.acquire_mutation() for x in pop]
+    print([x.get_genotype() for x in pop])
+    [x.acquire_mutation() for x in pop]
+    print([x.get_genotype() for x in pop])
+
 
 if __name__ == '__main__':
     main()
diff --git a/hamazaki1990/population.py b/hamazaki1990/population.py
index f46fed1..b6bc41d 100644
--- a/hamazaki1990/population.py
+++ b/hamazaki1990/population.py
@@ -10,10 +10,10 @@ def roulettechoice(individuals, cumsum_fitness):
 
 
 class Population:
-    def __init__(self, n, mutantrate=0, s=0):
-        num_mutant = int(n * mutantrate)
-        mutant_inds = [Individual(x, 1 + s) for x in range(num_mutant)]
-        wild_inds = [Individual(x) for x in range(num_mutant, n)]
+    def __init__(self, n, mutant=0, s=0, mutationrate=0.0):
+        num_mutant = int(n * mutant)
+        mutant_inds = [Individual(x, 1 + s, mutationrate) for x in range(num_mutant)]
+        wild_inds = [Individual(x, 1, mutationrate) for x in range(num_mutant, n)]
         self._inds = mutant_inds + wild_inds
 
     def get_ids(self):
@@ -44,6 +44,25 @@ def next_genmo(self):
         i_dying = random.randrange(size)
         self._inds[i_dying] = roulettechoice(self._inds, cumsum_fitness)
 
+    def acquire_mutations(self):
+        [x.acquire_mutation() for x in self._inds]
+        genotypes = [x.get_genotype() for x in self._inds]
+        return genotypes
+
+    def get_mutationlist(self):
+        genotypes = [x.get_genotype() for x in self._inds]
+        mutation_sites = []
+        for x in range(len(genotypes)):
+            mutation_sites.extend(genotypes[x])
+        mutation_sites = sorted(mutation_sites)
+        mutation_list = [[0 for x in range(len(mutation_sites))] for y in range(len(self._inds))]
+        for x in range(len(self._inds)):
+            for y in range(len(genotypes[x])):
+                i = mutation_sites.index(genotypes[x][y])
+                if i != "ValueError":
+                    mutation_list[x][i] += 1
+        print(mutation_list)
+
     def is_not_fixed(self):
         for x in range(1, len(self._inds)):
             if self._inds[0] != self._inds[x]:
@@ -106,6 +125,13 @@ def main():
         print(p2_2.get_ids())
     print(p2_2.get_fitnesses())
 
+    p3_1 = Population(10, 0, 0, 0.8)
+    p3_1.get_mutationlist()
+    print(p3_1.acquire_mutations())
+    p3_1.get_mutationlist()
+    print(p3_1.acquire_mutations())
+    p3_1.get_mutationlist()
+
 
 if __name__ == '__main__':
     main()