近日，中国科学院西双版纳热带植物园朱华研究员在最新研究中，提出了对海南岛动植物群起源与演化的新认识。2024年12月3日出版的《中国科学：地球科学》杂志发表了这项成果。

据悉，海南岛生物群的起源一直是一个基本的科学问题。此前研究人员对生物群、地质构造和古地磁对比研究显示，始新世时期，海南岛连接越南和广西，后向东南移动，到达现今位置。

本文主要从分子系统发育学和古植物学两方面论述其生物群起源。研究人员通过对海南岛生物类群的基因组、系统发育和分子生物地理学研究，确定了海南岛生物类群的形成与演化。研究显示，在始新世—渐新世期间，海南岛与越南、广西之间的陆地连接可以解释其进化早期（即中新世之前）出现和分化的属和种。根据东南亚构造理论，在中新世中期（约1500万年前），海南岛已经移动到现在的位置。分化时间较晚（15Ma以后）的物种的种群和遗传分化，可以合理地解释为海南岛与雷州半岛的接近（或陆地连接），使海南岛与大陆的遗传多样性交流成为可能，但也有例外。古植物学研究表明，始新世-渐新世时期，中国西南部和海南岛属亚热带植被区系。

然而，始新世晚期，中国东南部（茂名，今海南岛附近）的化石群则表现为热带雨林植被和植物区系。这表明，海南岛在古近纪可能位于广西和越南北部的西南边界附近或之上，而不是现在的位置。海南岛植物区系划分基本呈东北-西南倾斜分布格局。这种模式可以用古地磁研究提出的，海南岛在东南移动过程中的逆时针旋转来解释。分子系统发育、古植物学研究和海南植物多样性分布格局的证据，进一步支持了海南岛地质构造和生物区系比较研究提出的海南岛起源。本文还提出了其生物群演化的时间节点（中新世），从而为深入探索海南岛生物群的起源与演化提供了依据。

附：英文原文

Title: New insight into the origin and evolution of the flora and fauna of Hainan Island, China

Author: Hua ZHU

Issue&Volume: 2024/12/03

Abstract: The origin of the biota of Hainan Island, China, remains a fundamental scientific problem. Comparative studies on the biota, geological tectonics, and paleomagnetism proposed that during the Eocene, Hainan Island connected Vietnam and Guangxi, and then moved to the southeast to reach its present location. This review mainly discusses its biota origin from molecular phylogeny and palaeobotanical research. The formation and evolution of the biological groups of Hainan Island were identified via research on their genomes, phylogeny, and molecular biogeography. This research showed that the genera and species that appeared and diverged early in their evolution (i.e., before the Miocene) can be explained by the land connection between Hainan Island, Vietnam, and Guangxi during the Eocene-Oligocene. According to Southeast Asian tectonic theory, in the Middle Miocene (at about 15 million years ago), Hainan Island had moved to its present position. The population and genetic divergence of species with late divergence times (after 15 Ma) can be reasonably explained by the close proximity (or land connection) between Hainan Island and the Leizhou Peninsula, enabling genetic communication between Hainan Island and the Chinese mainland, but have exceptional cases. Conclusions have been obtained through palaeobotanical studies, showing that in the Eocene-Oligocene period, southwest China and Hainan Island had subtropical vegetation and flora. However, the fossil group in southeast China (in Maoming, near present-day Hainan Island) in the Late Eocene indicated a tropical rainforest vegetation and flora. This suggests that in the Paleogene, Hainan Island may have been located near or on the southwest border of Guangxi and northern Vietnam, rather than in its present location. The floristic division of the flora of Hainan Island basically presents a northeast-southwest inclined distribution pattern. This pattern can be explained by the counterclockwise rotation of Hainan Island during its movement to the southeast as proposed by paleomagnetism research. The origin of Hainan Island as proposed by its geological tectonics and comparative research on its biota is further supported by evidence from molecular phylogeny, paleobotanical studies, and the distribution pattern of plant diversity in Hainan. In this paper, the time node (in the Miocene) of the evolution of its biota is also proposed, thereby providing a basis for the in-depth exploration of the origin and evolution of the biota of Hainan Island.

DOI: 10.1007/s11430-024-1440-3

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-024-1440-3