This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Opportunities to directly observe how life colonizes newly formed land and how ecosystems subsequently develop are exceedingly rare. In a study published in the Journal of Plant Research, researchers at University of Tsukuba used genetic analyses to investigate the origin of Eleusine indica, a grass species found on Nishinoshima, an active volcanic island in the northwestern Pacific south of mainland Japan.
Having newly emerged, the island offers a unique natural laboratory for understanding the earliest stages of biological colonization and ecosystem development. Since new land emerged during volcanic activity in 1973, Nishinoshima has been continuously expanding, yet only a small number of plant species have been recorded. During a survey in 2019, three plant species, including E. indica, were found surviving within a small, 0.5-hectare (1.2-acre) remnant of the original island surface.
Because human access to Nishinoshima is strictly restricted, it was unknown how these plants established populations on such a remote oceanic island without human assistance. The research team analyzed DNA samples of E. indica collected from Nishinoshima, mainland Japan, the Ogasawara Islands, the Ryukyu Islands, Indonesia and other locations using advanced genetic techniques. The results indicated that the Nishinoshima population is most closely related to populations from the Ogasawara Islands, Okinawa and Indonesia, suggesting dispersal from tropical regions through Okinawa and the Ogasawara Islands.
Additionally, the analyses revealed extremely low genetic diversity within the Nishinoshima population, suggesting that it likely originated from a single seed or only a few seeds. Seabirds, including the brown booby (Sula leucogaster), commonly breed on and around Nishinoshima. Thus, the researchers propose that seeds were transported over long distances by birds and subsequently established on the island.
This study provides rare genetic evidence of how plants colonize newly formed volcanic islands and offers important insights into the earliest stages of ecosystem establishment in isolated oceanic environments. The findings also highlight the potential importance of seabirds in connecting distant island ecosystems via long-distance seed dispersal. Koutaro Maeda et al, Origin of the Eleusine indica population on the active volcanic Nishinoshima Island, Japan, Journal of Plant Research (2026).
DOI: 10.1007/s10265-026-01738-9 Swati Mestri holds a bachelor's degree in Electronics Engineering and has worked as a content editor since 2019. She has experience editing research documents across technology, health care, and materials science, and has a particular interest in technology and space. Full profile → Bachelor's in mathematical biology, Master's in creative writing.
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