Seagrass is the world’s oldest known living organism
Mediterranean seagrass Posidonia oceanica ranks amongst the slowest-growing and longest-lived plants in existence, according to Carlos Duarte of the University of Western Australia in Perth. Duarte estimates the minimum age to be between 80,000 and 200,000 years, projecting the origin of the clones well into the late Pleistocene, and making it the oldest known living organism on the planet.
Seagrasses reproduce by cloning and can form extensive meadows considered to be one organism.
Despite its longevity, Posidonia oceanica may well be challenged by the unprecedented rate of environmental change imposed by current global climate change. Seagrasses are the basis of essential coastal ecosystems but are waning worldwide, and P. oceanica meadows are declining at an estimated rate of about 5% per year. The results reported in the February 1st edition of PLoS ONE suggest that clones of that species have adapted to a broad range of environmental conditions, but the unprecedented rate of global climate change, together with the steep decline in seagrasses already observed for the past 20 years, are raising serious concerns about the continued survival of this long-lived species.
