The Wallace Line
Alfred is very notable in the world of geography as well, but both his biology and geographic experience came together when he spoke about the Malay Archipelago. This had to do with a clear separation between Asia and Australia as a result of a line that animals and fauna picked themselves seemingly. Today, we call this the Wallace Line. Alfred discovered that the Indonesian Archipelago was able to be separated into two different parts.
A Western Portion is easily more Asian as it shows proof of creatures that connect to Asia. An Eastern Portion, however, shows fauna that connects to the Australian region. Why is this so compelling? Because it proved to us that, like humans, animals and plants also pick the conditions that are best for their survival. If the two worlds met between the West and East, they’d naturally take each other out. The separation, however, allows us to keep them apart and both can survive as a result.