Can you tell the difference between similar ethnic groups throughout the world?

I was recently talking to a friend that lives in Europe (Latvia) and he was telling me how Europeans look different in different countries. Now I for one can’t tell the difference between Latvian and Swedish or German and Dutch. Do people in different countries in Europe look that different? What about the Asian countries. Can you tell the difference between someone from Mongolia and someone from Malaysia? What about South America, Is there a difference between Argentineans and Brazilians? Can you tell the difference between different ethnicities of the world?? What are the differences between countries that live close together?

P.S Please don’t comment saying “It does not matter what race you are” This discussion is for telling apart different races, Thank You


[edit on 18-2-2010 by Maddogkull]