[norton]

If "At this time the ancient continent known as Sundaland – an extension of the Asian landmass as far as Borneo and Java – was flooded to create the present-day archipelago."

And "The present-day coastline is about twice as great as it was 15,000 years ago."

How come sundaland didn't reappear when things cooled down and all those other shorelines expanded?

[gleeaikin]

“How come Sundaland didn’t reappear when things cooled down and all those other shorelines expanded?”

Sundaland didn’t reappear, because things did not cool down. Most people, and unfortunately a lot of them are archeologists and anthropologists and should know better, don’t realize that at the end of the last ice age the oceans were 400 feet lower than they are today. As the water rose, many hills became islands, creating much more shoreline than existed previously.

[aruanan]

How come sundaland didn't reappear when things cooled down and all those other shorelines expanded?

Because there hasn't been another ice age yet to tie up all that ocean water in the form of ice and snow. We're still in the interglacial period, though probably in the last bit of it.