Meet your maker: Homing in on the ancestor of all life

 作者:密涅獒     |      日期:2019-03-30 05:20:16
By Michael Le Page Video: How life on Earth began What was the last shared ancestor of all life like? How did it make its living? A radical new answer could explain some of the most mysterious features of life IN 1859, when Charles Darwin published On The Origin of Species, he dedicated an entire chapter to the problem of missing “intermediate links” – transitional forms that bridged the evolutionary gaps between closely related species. If his theory was correct, the fossil record should be full of them. Where were they? At the time it was a real problem, as few such fossils had been found. Then came the spectacular discovery, in 1861, of Archaeopteryx, with the wings and feathers of a bird and the teeth and tail of a dinosaur. Since then we have discovered a multitude of intermediate links: fish that could crawl, lizards with mammal-like jaws, whales with legs, giraffes with short necks and many others. But there’s one we are unlikely ever to find: the link between the earliest proto-life and life as we know it, also known as the last universal common ancestor, or LUCA. LUCA lived around 4 billion years ago – a tiny, fragile life form that is the direct ancestor of every single living thing, from aardvarks to zebras. It wasn’t the very first life: thousands, if not millions, of years of evolutionary experimentation preceded it. But understanding LUCA would give us our best view yet of the origin of life. What was brewing in the primordial soup? (Image: