In the last post we have seen anomalies to Dravidian b-v isogloss due to Magadhi Prakrit adstratum. I believe these words entered between 500BCE-0, or the fifth phase where guilds entered from the eastern regions. But there could be IE borrows into Dravidian languages that show typical sound changes comparable to to core Dravidian vocabulary. And these IE migrations could be part of Dravidian expansion in South India from Central or West India.
One of the earliest IE migrations to South India was that of herders. Known in north India as Yadava; their old identity in South was Ideya(Yes, herders in South India have appreciable frequency of Y-Haplogroup R1a1). Ravi Mundkur has clearly shown that Ideya is in fact derived from Yadava. I have already mentioned that herders might have migrated south around 1000BCE. Perhaps Dravidian expansion to south started between 1500BCE-1000BCE. Let's examine a word related to herding.
The term for cattle (pazu in Sanskrit) has entered Dravidian languages. In Kannada, cow is called hasu.(Please note there is also a Dravidian word hasu(Le) in Kannada which means child. Similar words for child, boy, calf ..payal, pay, peyy etc... is found in other Dravidian languages but different from present word which is borrow from IA languages). In Kasaragod variant of Malayalam it is called pay. The s->y change between Kannada and Malayalam can be observed here. Incidentally, standard dialect of Malayalam employs the Sanskrit word.
1. Origins of Indians version-9.2
2. Iddya to Yedapadavu