Long time ago there was a nuclear war in India. In the Hindu Holy book there’s mention of a a firey weapon form the sky that consumes everything on the ground. Secondly there’s certain type of crystals (trinitite) only formed when sand is molten at extremely high temperatures.
This types of crystals are also found in some regions of the Sahara ️. In India it’s very common for cows to give birth to 2 headed calves or children born with 25 fingers or toes among other deformities.
It’s because of the class system. Basically everyone has to marry from their bloodline. For those with good lines, the results are excellent. They can also improve their genes by picking the occasional good looking beauty.
For the lower class, they’re stack with accumulation of dangerous recessive genes with no wag to escape