Evolution: East versus West: a floral history of China

The east and west of China are home to species of flowering plant with distinct evolutionary histories, according to a study published in Nature. The paper suggests that the east of the country represents a floristic ‘museum’ owing to the presence of many species with ancient origins and the west can be considered an evolutionary ‘cradle’ for recently diverged species.

China is home to nearly ten per cent of worldwide angiosperm (flowering plant) species and is considered to be both a refuge for species with ancient origins and a cradle for the rapid emergence of recent ones. However, no detailed study has addressed when and how the major components of the Chinese angiosperm flora assembled to form the present-day vegetation.

Zhi-Duan Chen and colleagues investigated the spatial and temporal divergence patterns of 92% of angiosperm flora in China. The authors found that 66% of angiosperm genera in China did not originate until early in the Miocene epoch (approximately 23 million years ago). The authors also found that eastern China, including areas from central to southern China, tends to be home to older lineages of species in comparison to the west of the country. By contrast, western China, including the arid northwestern portion of the country and the Qinghai–Tibetan Plateau, contains more recently diverged flowering plant species.