Well actually in Kathkalli it is not just a mere dance..... but Dance is a Medium to depict the Story of Brave King(s)....
Kathkalli is not only popular in India or Sri Lanka but also in Singapore, malaysia, Indonesia, Combodia...there costume and Make - Up get change.... but use of EYEs and gestures remains the Same.....
Regarding Bio- Diversity different cultures in India.... at avery 100 Kms difference the Taste of Water and Local dialect get change..
In Himachal Pradesh.... it is visible to the extent that.... on 1 mountain If People are speaking 1 language then on otherMountain... some times in front one which is only divided by a river or stream even... we can found completly Different language....
And this is the reason even in Indian Armed Forces u can find completly different people......
For Indian ....... u can not say tht He looks like"Indian".... until and otherwise He tells u Proudly that " Hindi Hai Hum"... " Watan hai Hindustan Hamara"