Ten thousand years ago, isthmuses or land bridges supposedly existed, letting primitive inhabitants wander and navigate from one region to another. The Philippines believed to be part of mainland Asia through exposed Sundaland, and that there was an isthmus between Borneo and Palawan, which then the gateway to Luzon. By all reports, the Philippines was not connected to China.
Theoretically, the Philippines’ major islands, Luzon, Visayas and Mindanao, were interconnected with each other 10,000 years ago during the latter part of the Ice Age.
In the visual representation, Taiwan was then attached to mainland China. In the same way, Brunei, Malaysia, Indonesia, Singapore, Thailand, Laos, and Vietnam formed one Asian landmass through the exposed Sundaland during the Paleolithic, precisely the old stone age period, when humans, the evolving dominant land animal, lived in caves.
The reason for the emergence of these land bridges was the extreme cold global temperature, approximately between 8 and 3-degree Celsius, in which sea level fell about 120 meters at the latter part of the Paleolithic or the Old Stone Age.
Unbelievably, Land Bridges did exist.