Evolution of Northern Hemisphere conifers

Researchers report the evolutionary history of Pinus, the largest genus of conifers. Unlike most organisms with a distribution following a latitudinal diversity gradient, conifers in the Northern Hemisphere are found mostly in middle-latitude mountainous terrain. Xiao-Quan Wang and colleagues explored the macroevolution of Pinus to reveal the mechanisms underlying this unique distribution pattern. Using 1,662 genes from transcriptomes, the authors reconstructed the evolutionary history of Pinus, covering nearly all species in this genus. The results revealed that although the origin of Pinus is ancient, approximately 90% of species in the genus originated in the Miocene, suggesting a re-diversification of the genus in the Neogene. The results also showed that the midlatitude species are older than species at other latitudes. An analysis of environmental factors suggested that topography has likely played a key role in pine diversification. The authors also found evidence of development of fire-adaptation syndromes over time, as fire intensity and frequency increased from the early Oligocene to the late Neogene. According to the authors, lineage accumulation over evolutionary time scales in the midlatitude region, rather than diversification rate acceleration, may have given rise to the high species diversity of conifers.

Article #20-22302: “Phylogenomic and ecological analyses reveal the spatiotemporal evolution of global pines,” by Wei-Tao Jin et al.

MEDIA CONTACT: Xiao-Quan Wang, Chinese Academy of Sciences, Beijing, CHINA; tel: 86-10-62836502; email:

[email protected]

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