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1billionyearold black shale from a quarry in Gabon the earliest evidence of a revolutionary development in the history of life on Earth the ability of organisms to move from one place to another on their own PositiveWASHINGTON Scientists have discovered in 2 http://www.reuters.com/places/africa/article/us-science-mobility/earths-earliest-mobile-organisms-lived-2-1-billion-years-ago-idUSKCN1Q029U2019-02-12