I'm compiling a list of primary sources on jeets proving they're neither human nor compatible with humans, and to show that their species has remained unchanged and is incapable of changing. This is a work in progress so feel free to contribute.

Megasthenes (active c. 302–288 BC) — Indica (now lost; preserved in Strabo, Arrian, Diodorus)
>The Indians in general are of excessive cowardice and are unfit for war. They lack manly spirit

Strabo (c. 64 BC – 24 AD) — Geography, Book 15
>The Indians are naturally disposed to lying and boastfulness
>They are servile and effeminate… lacking in courage and ambition
>They are all impostors and quacks

Curtius Rufus (active c. 40–50 AD) — Histories of Alexander the Great, Book 9
>Indians are most effeminate of all nations… they adorn themselves like women and fear death above all things

Alexander Romance / Pseudo-Callisthenes (earliest version c. 3rd century AD)
>Indian kings like Porus are depicted as arrogant and foolish, easily humiliated by Alexander. (Date context: Original Greek text composed 3rd century AD, drawing on oral and legendary materials from c. 300–100 BC.)

Arrian (c. 86–160 AD) — Anabasis of Alexander, Book 6
>Indians go about naked all the time... Their food is raw vegetables, and they eat the bark of trees… they are more like wild animals than men