Researchers examined the plant life in the China's Hengduan Mountains, the Himalaya Mountains, and the Qinghai-Tibet Plateau. Using DNA to build family trees of species, they learned that the ...

Earth's geographical surfaces have been formed over millions of years, and various current theories aim to explain their formation. The most popular theory, called the "plate tectonics theory," states ...

One of the big questions in biology is why certain plants and animals are found in some places and not others. Figuring out how species evolve and spread, and why some places are richer in species ...