UK (BBN)-Nowadays Arabia is a fierce desert, but it was once densely vegetated, and could have been a home to the first humans that left Africa.
When most of us think of Arabia, we think of rolling sand dunes, scorching sun, and precious little water, reports BBC.
But in the quite recent past it was a place of rolling grasslands and shady woods, watered by torrential monsoon rains.
The finding could help settle how and when modern humans first left Africa, where our species evolved.
If Arabia was once lush and fertile, it would have been an ideal place to migrate to.
"There were more windows of opportunity for humans to leave Africa than previously thought," says lead author Ash Parton of the University of Oxford in the UK.
Our hunter-gatherer ancestors "wouldn't have been able to exist in many areas of Arabia as it is today," says Parton.
"At present the Indian Ocean Monsoon just clips the very southern edge of the peninsula," so the rest of Arabia is desert.
His team's findings suggest that the monsoon pushes further into Arabia every 23,000 years, allowing plants and animals to flourish.
BBN/SK/AD-24Feb15-1:30pm (BST)