* Razib's pinboard at Gene Expression notes the Wikipedia article on the Vedda language. Until it became extinct or moribund in the 1990s it was the language of a hunter-gatherer group of Sri Lanka. It was one of the last South Asian languages that was originally neither part of the Dravidian nor the Indo-Aryan nor the Austro-Asiatic nor the Tibeto-Burman language families of South Asia, although continued exposure to the local Dravidian language over 2,500 to 3,000 years resulted in substantial borrowing of words between the two, with some Vedda words borrowed from early Dravidian dialects that are no longer used in modern Dravidian languages.
The Vedda language is a vivid reminder of that fact that 6,000 years ago, almost nobody in India spoke either the Dravidian languages, which started to rapidly expand with the South Indian Neolithic around then, or the Indo-Aryan languages, which probably appeared in South Asia around 4,000 years ago. Austro-Asiatic languages (i.e. the Munda languages of South Asia) are probably roughly contemporaneous in their arrival from Southeast Asia with these two language families and probably arrived around the same time as rice cultivation began in India. The Tibeto-Burman languages are the most recent arrivals in South Asia and form the most genetically distinct populations of India. Most of the preceding South Asian languages went extinct in prehistory before they were attested. But, it is a mistake to think of the Dravidian languages as the language family of the indigeneous hunter-gatherers of India since times immemorial. If Proto-Dravidian was indigeneous to India at all, it was probably spoken only by one small tribe that happened to be the first to master farming in the region.
* Similar points about the pre-Indo-European linguistic landscape can be made about Europe at a fairly similar time depth (at least relative to the appearance of the Neolithic revolution there).
* I have never really taken seriously the possibility that there could have been Bronze Age maritime trade with West Africa, even though there was martime trade with East Africa at least as far back as the early Iron Age and quite possibly much earlier. But, a new post at Maju's blog notes increasing evidence of Bronze Age maritime colonization of the Azore Islands in the Atlantic Ocean. West Africa would have been no harder to reach. So, the possibility of Bronze Age maritime trade with West Africa while still somewhat doubtful, is no longer something that seems highly unlikely.
* The use of the wheel for practical transportation purposes is about 5,500 years old and probably originated in the Pontic-Caspian Steppe. The existence of a common source word for this in Proto-Indo-European lingustic reconstructions argues for the youth of this language family and its origins on the Steppe, as do borrowings of even very archaic forms of Indo-European words into Uralic languages.
* It is not at all obvious that the root of the Anatolian Indo-European languages (most famously Hittite), is in fact in Anatolia. The earliest attestations and archaeological indications of the earliest cores of the Hittite people and the Indo-Aryans is about 4,000 years ago and both populations introduce metal working techniques that were invented only a little earlier in the Caucasus mountains. Other kinds of historical and archaeological evidence point to both as being intrusive, and the arrival of Indo-European Greek speakers in the Aegean region is a historically attested event and happened within the last 4,500 years.
* Early Iron Age Judaism, as described in the Torah, looked a lot more like modern fundamentalist Islam in practice than it does like the Rabbinic Judaism of the last two thousand years. The last two thousand years also marks a time, when, despite significant modern endogamy preferences among Jews, the genetic evidence indicates that the people of the Jewish diaspora admixed heavily with non-Jewish peoples. By ancestry, Ashkenazi and Sephardi Jews are much less Semitic than, for example, modern Saudi Arabians.