Problem adding List<> objects to another List<>

Hey all,

Currently I've got a two lists for vector3's and quaternions and I'm adding them to a list of these lists so I can keep record of object positions each time the function is called. Everything seems to work largely as intended, except it seems that if I replace a list with a new set of data (after passing it into the list of lists), the original data that got added into the list of lists is also changed.

Is there a way of just adding the data from a list to another array type variable without having all the values reset?

     <Vector3> pos = new List<Vector3>();
     List<Quaternion> rot = new List<Quaternion>();
     List<List<Vector3>> posArray = new List<List<Vector3>>();
     List<List<Quaternion>> rotArray = new List<List<Quaternion>>();

  void updateVariables()
     {
         pos.Clear();
         rot.Clear();
         for (int i = 0; i < boxes.Length; i++)
         {
             pos.Add(boxes[i].transform.position);
             rot.Add(boxes[i].transform.rotation);
         }
 
         posArray.Add(pos);
         rotArray.Add(rot);
     }