What is Humboldt’s enigma and what does it mean for India? | Explained Premium

Explorers and scientists have long wondered why some areas are more biodiverse than others, with mountains being a key exception to the expected decrease in diversity away from the tropics, known as Humboldt's enigma. The Shola Sky Islands are a good example in India, and need more research and support.

Where is biodiversity concentrated?

Explorers and naturalists have been asking this question for centuries. Many have also been curious why some areas are more biodiverse than others.

One of them was Alexander von Humboldt (1769-1859) – a polymath who recorded observations on various natural phenomena across the fields known today as geography, geology, meteorology, and biology.

Once, when exploring South America, he recorded the distribution of plants on a mountain. He also noted how climates were similar across various mountains in different parts of the world – but where specific features occurred on a mountain varied with elevation.

From his various studies, Humboldt suggested there was a relationship between temperature, altitude, and humidity on one hand and the occurrence patterns of species – or their biodiversity – on the other. His example of choice was the Chimborazo mountain in Ecuador, which has today become an important illustration of mountain diversity.

Two centuries later, a group of biogeographers – scientists who explore the relationship of diversity with geography – used modern tools to take another look at the drivers of biodiversity.

Based on their findings, they proposed their own version of the link between biodiversity and mountains and called it Humboldt’s enigma.