Google Analytics shows real time visitors but reflects 0 visitors historically

To get the same, Google has launched new Real Time API. With this API you can easily retrieve real time online visitors as well as several Google Analytics with following dimensions and metrics. https://developers.google.com/analytics/devguides/reporting/realtime/dimsmets/

This is quite similar to Google Analytics API. To start development on this, https://developers.google.com/analytics/devguides/reporting/realtime/v3/devguide

The following is specific to the structure you've provided, it could be made more generic fairly easily. I'm sure the addChild function can be simplified. Hopefully the comments are helpful.

function toHeirarchy(obj) {

  // Get the organisms array
  var orgName, orgNames = obj.organisms;

  // Make root object
  var root = {name:'ROOT', children:[]};

  // For each organism, get the name parts
  for (var i=0, iLen=orgNames.length; i<iLen; i++) {
    orgName = orgNames[i].name.split('.');

    // Start from root.children
    children = root.children;

    // For each part of name, get child if already have it
    // or add new object and child if not
    for (var j=0, jLen=orgName.length; j<jLen; j++) {
      children = addChild(children, orgName[j]);      
    }
  }
  return root;

  // Helper function, iterates over children looking for 
  // name. If found, returns its child array, otherwise adds a new
  // child object and child array and returns it.
  function addChild(children, name) {

    // Look for name in children
    for (var i=0, iLen=children.length; i<iLen; i++) {

      // If find name, return its child array
      if (children[i].name == name) {
        return children[i].children;        
      }
    }
    // If didn't find name, add a new object and 
    // return its child array
    children.push({'name': name, 'children':[]});
    return children[children.length - 1].children;
  }
}