Assorted Links

1. How Many People Have Ever Lived on Earth?  (via @blqueiroz)
   
   
2. Openly available datasets about Amazon
   
   
3. The 25 Least Visited Countries in the World (via Drunkeynesian)
   
   
4. The Flynn effect vs. population aging (via MR)
   
   
5. 3D Mapping in R
   
   
6. An advice for young researchers
   
   
7. Human Development Index of Mexico municipalities
   
   
8. An excellent discussion on the The Challenge of Ageing (and a related essay competition)
   
   
9. Length of the average dissertation (via Flowing Data)
   
   
10. What if we replaced the moon with Jupiter or Saturn?
    
    
11. Population density in select cities around the world