Uncovering the Billion-Year-Old Lost World of Ancient Microbes.

Fossilised ‘protosteroid’ molecules discovered in 1.6 billion year old rocks could be signs of a hidden world of ancient organisms belonging to the earliest forms of complex life. The finding suggests that short-lived precursors in modern steroid biosynthesis were once functional end products in their own right, solving a decades-old mystery surrounding the early evolution of eukaryotes. The discovery offers a plausible explanation for the absence of sterols beyond 800 million years ago and illustrates that most life that ever existed is now extinct and therefore often overlooked.