गारो, खासी और जयंतिया जनजातियाँ मुख्य रूप से किस राज्य में निवास करने वाली मूल निवासी समुदाय हैं?

In traditional anthropological classification of human races, which racial group was characterized as 'yellow-skinned'?

What is the approximate estimated proportion of ecumene (habitable) and non-ecumene (uninhabitable/sparsely inhabited) areas on the Earth's surface?