According to the new research by scholars at the University of Southampton and Queens University, Belfast, nutritional and security considerations seemed to have been the main criteria, the BBC reported.
A survey of 25 major British and north-west French sites dating from 500,000 to 200,000 years ago has revealed that early humans - members of the now long-extinct species Homo heidelbergensis - predominantly chose to live on islands that were located in major rivers' flood plains.
The flood plain allowed them to develop a virtually perfect 'Palaeolithic diet' in which protein consumption was balanced by carbohydrate and fat intake. This was because, more than any other ecological zone, river flood plains produced unusually rich grass which attracted larger numbers of big herbivores (especially wild horses).
It also attracted substantial numbers of other animals - including deer, rhino and beavers, as well as large flocks of water birds. What's more, the flood plain generated vast numbers of water plants with nutritional edible roots.
Flood plains also provided raw material for making tools and lighting fires. River gravels were rich in flint nodules which could be transformed into axes, cutting tools and scrapers.
Although flood plains were economically attractive to early humans, they were also very dangerous because, just as the zone's rich fat and protein resources attracted humans, they also attracted big cats like lion and hyaena.
To avoid these predators, Homo heidelbergensis only favoured particular parts of flood plains - namely the islands formed by a river's intersecting channels.
The research has been published in PLOS ONE.
--ANI (Posted on 11-12-2013)