The Indus date has been pushed back to 7500 BC, so says a recent research (given below). For those reading through the Ithihasas and Puranas of India, this is not a news at all, for we are able to decipher the history of the world running into tens of thousands of years from these texts. When we read them in conjunction with Tamil sangam inputs, we get a better picture of the past.
For example, the rise of human civilisation in the past one lakh years started in the southern seas in the Indian ocean – a fact which most of genetic researchers agree with. It had gone to the Northern hemisphere about 60,000 years ago after the Toba-effect subsided. Then when the North was covered with ice, a shift happened from North to South – not through India but through China to Sundaland (present day Indonesia). From Mahabharata narration (Anusasana parva – chapter 93) it is known that a migration following the sun's movement happened from north to south. This is cleverly explained in this chapter using the etymological meanings of names of the seven rishis and others.
From a region that was supplying Sibi (Typha angustifolia) in the northern latitudes, people had moved to the South where lotuses were growing. These two planets signify availability of food as these plants were completely edible with each part of them being eaten by people. Sibhi grows well in regions 40 degrees North, thereby locating the region at or near Altai mountains. (green circle in the picture below)
The interesting information from archaeology is that this region had Denisovan population which had become extinct around 40,000 years ago.
http://archaeology.about.com/od/dathroughdeterms/qt/denisova_cave.htm
The interesting part of the find is that the DNA deduced from this find is related to the DNA found in Pacific islands near Australia.
http://www.nature.com/news/2010/101222/full/4681012a.html
This goes to show that the Denisovan population once had its ancestry in the Southern hemisphere. So from south to north, some migration had happened which stayed put near Altai mountains or Siberia. When the climate became unbearable, the surviving population had migrated to the south which is what is being indicated in the Mahabharata (http://ancientvoice.wikidot.com/src-mbh-13:section-93 )
The description of finding of the Lotus in a pond signifies a new era of growth of human population in the south which happened around 30,000 years ago when Sunda land was a brimming landscape. The rationale behind locating this region for new growth of humans is because Yatudhani, the demoness who was involved in that description was said to be hiding in that lotus pond. Yatudhanaus were the Danava asuras who shared the Patala, Hiranyapura (of Hiranya kasipu) with Daityas. Even today many people in China and Vietnam use all parts of lotus for food like how Sibi was / is being used in Altai regions.
A decipherable history can be started from Sundaland which got that name from Sunda – Upsunda episode in which Tilotthama was a small (like tila, the sesame seed in her name) trigger in the mantle which grew up and blew off the twin volcanoes called Sunda and Upasunda. Shiva turning his head all around to see Tiloththama can only be explained as a matter of samhara (destruction) by fire spewed on all sides of the volcanoes. The volcanoes stripped off the land on which they stood leaving what is now called as the Sunda straits.
An underwater exploration might reveal a blast off in the past.
The entire region of Sundaland was home to Daityas and Danavas until 7000 years ago. Until Mahabharat times, Danavas such as Kalakanjas and Nivata kavachas were there in this land who were defeated by Arjuna. The route taken by Arjuna to reach to these danavas and also the route described by Narada to Matali concur with each other and point out to Sundaland only. The details are being written in my Tamil series first and then translated later to be posted here. For the moment, I am saying these to show that history of 20,000 + years ago at Sundaland had all the trappings of the puranic narrations of daityas and danava asuras. Somewhere closely the early Pandyans rose in deep south around 12,000 years ago that was when the first sangam was established as per Nakkeeranar's account in Irayanaar Kalaviyal.
To tell it in a nutshell, take a look at the picture below.