As I write this I am looking out over the South China Sea from the Malaysian port town of Kota Kinabalu. The tide is going out and small groups of people slog across the exposed seabed to collect shellfish. Just 50 kilometers to the east lies the peak of Mount Kinabalu, at 4,095 meters the highest mountain between the Himalayas and New Guinea. It towers over its surroundings with such grandeur that it led American pilots flying over Sabah during the Second World War to report: "Say, that God-dammed thing cannot be 13,000. Why that's nothing. It must be near as high as Mount Everest."[1]

It's hard to imagine a starker contrast with the flat world around me. Nevertheless, in a few days I will trade the beaches and hillsides of the city for the montane forests of Borneo. I am joining a team of 40 scientists of the Naturalis Biodiversity Center and the Malaysian nature conservation organisation Sabah Parks on an expedition to the Heart of Borneo, where they intend to unravel the origins of the mountain's mysterious biodiversity.

Because of its height, Mount Kinabalu is something of an ecological island. Most species well adapted to the cold and wet conditions at the top are stuck there. They can't compete with species that thrive at the higher temperatures of the lowlands, and there are no mountains anywhere near they can cross to—the closest peak approaching 3,000 meters is 900 kilometers away, in the Philippines. That's a bridge too far. As a result, Mount Kinabalu gave rise to a spectacular community of organisms that occur only there and nowhere else on earth. We call these species endemic species, or endemics.

Mount Kinabalu is home to thousands of endemic species—from orchids, land snails, and frogs, to fungi, jumping spiders, and shrews. Their origins are a mystery. Are they young species, recent evolutionary offshoots from the species that live in the lowlands? Or perhaps relicts from a time when Borneo was much cooler? In other words: is the mountain a hotbed or rather a storehouse of evolution? That is the question the expedition team is setting out to answer.

To understand the origins of the life on Mount Kinabalu we must look back in time to when the mountain formed. Luckily, evolution leaves traces of its path hidden in the DNA. By comparing DNA of the 'stuck' endemics to that of related, more widespread species, we can unravel this path. Unfortunately, traces fade with time and so does the record of evolution captured in DNA. In this we find another reason why Mount Kinabalu is such a special place to study evolution. It's not only the highest mountain in the region, but also the youngest—the traces of evolution haven't faded.

So over the next two weeks, the expedition team will sample the life on Mount Kinabalu and then travel down to the surrounding Crocker Range to collect related, more widespread species. And finally, to crack the mountain's mystery, the DNA lab of the Naturalis Biodiversity Center back home will analyze the samples they collect.

Tomorrow, we leave Kota Kinabalu and head for the mountain. Stay tuned!

[1] Tom Harrison (1959), World Within.

Image credit: Lithograph by Thomas Picken. Reproduced from: St. John, S. (1863) Life in the forests of the Far East, Vol 1. Smith, Elder and Co., London.