scientists “biogeographical boundary” This invisible barrier, as he calls it, runs the length of the Malay Archipelago, the largest collection of islands in the world with more than 25,000 islands.

On the west side; There are rhinos, elephants, tigers and woodpeckers. Once you cross the western line Living species change suddenly. Marsupials and Komodo Dragons will appear in front of you. So how is such a thing possible and why does it exist?

A man named Wallace discovered both the real and unreal lines and made some very interesting findings.

This line, called the Wallace Line, was first drawn in 1859 by a man named Alfred Russel Wallace. Wallace was also a co-discoverer of natural selection.

During his eight-year tour of the Malay Archipelago, he continually moved from island to island interesting distribution of living species investigated. While he was in bed with malaria during part of this trip, the idea occurred to him that there was a border dividing the region.

Because the changes in the animals were not subtle and gradual, they changed as soon as the limit was crossed. suddenly and clearly It was changing. It seemed like two different worlds. Of course, there were some reasons that made something like this possible.

The geological past shapes the biological present.

The distribution of living species today is in a certain sense ancient geological events However, such a thing was not yet known at the time Wallace made his discoveries. He examined the islands and came to the conclusion that the western islands must once have been connected to each other and to the Asian mainland. The Eastern Islands were the remains of an ancient Australian continent.

Although today they are surrounded by shallow seas, this only happened recently. geologically speaking, this is the result of sea level rise. How else would large animals like tigers and rhinos reach the islands? So they are now separated by large bodies of water that these species cannot pass through.

During this change, deeper waters with strong currents existed between the two regions, at times when sea levels were lower. many species could not move from continent to continent.

The same invisible line exists elsewhere too.

Places where sea levels are higher and the continents are divided into contiguous island groups still prevent the passage of many modern-day species. Even even birds and insects This follows the rule of the invisible line.

Wallace put the pieces of the puzzle together, but there was another important theory.

surface of our planet not static, dynamic. It consists of separate large parts and plates that have moved and collided with each other over very long geological times. This situation, which we can explain within the framework of plate tectonics theory; It was accepted in the 1960s, long after Wallace’s death.

Plate tectonics has had many effects on our planet, including the formation and deformation of continents, the rise of islands and the formation of mountains. The Malay Archipelago is one of the most complex tectonic regions in the world. diversity of living species This makes it clear.

Our other content that may interest you: