Decode mystery why tropical forests are more species than temperate

Tropical forests evolve twice as fast as their cousins ​​in temperate regions. This may explain why tropical regions have more species than other regions.

A New Zealand study measured the rate of DNA change over millions of years by 45 pairs of woody plants with close relatives.

" For each pair we use two species that have families close together, one from the tropics and one from the temperate zone, " said study co-author Dr. Len Gillman from Auckland University of Technology.

The study compared species like conifers, kauri pine, acacia trees in tropical regions in Australia, Papua New Guinea and the Amazon region with their relatives in temperate regions in countries like New Zealand and the United States. , and Tasmania island of Australia.

By comparing a particular piece of DNA in each pair and with their common ancestors, the team can calculate the rate of evolutionary change.

" We found double the number of changes in tropical species ," Gillman said. " If you have twice the rate of evolution, that means you have more than twice the chance to generate and accumulate new species ."

The team conjectures the faster rate of evolution in tropical plants due to faster growth and metabolism. Faster metabolism will cause cells to divide more times and increase the chance of mutation.

T. An