Four billion years ago, sometime around Earth's 560 millionth birthday, Luca was born. Luca is your great-to-an-infinite-degree grandmother and grandfather, as it is your dog's and your goldfish's and your ficus'. Every living thing on Earth owes it existence to Luca, whose very name stands for "Last Universal Common Ancestor." It is the origin of life on Earth, from which the rest of us evolved. And now scientists believe they have mapped a genetic picture of the qualities that would have belonged to Luca, giving us a startling look at how life on Earth might have begun: ...By comparing their sequence of DNA letters, genes can be arranged in evolutionary family trees, a property that enabled
Life forms were pretty underwhelming four billion years ago. Primitive microbes dwelled in iron-rich hot springs. They probably didn't look like much or do a whole lot - they lived off hydrogen, carbon dioxide and nitrogen gases bubbling through their warm, watery home. But they're your ancestors - and the last common ancestor of all life today, according to a German genetic study. Researchers at the University of Düsseldorf, wanting to unpick what the last universal common ancestor was like, sorted through 6.1 million genes found in single-celled organisms today. In a study published in Nature Microbiology, they found 355 protein groups that were likely retained from our ancestor microbe, from
Who’s your daddy? An unknown hominin species that bred with early human ancestors when they migrated from Africa to Australasia has been identified through genome mapping of living humans. The genome analysis also questions previous findings that modern humans populated Asia in two waves from their origin in Africa, finding instead a common origin for all populations in the Asia-Pacific region, dating back to a single out-of-Africa migration event. Modern humans first left Africa about 60,000 years ago, with some heading west towards Europe, and others flowing east into the Asia-Pacific region. Previous research looking at the genomes of people living today has revealed that the Asia-Pacific
A few weeks ago, Dear Science featured news that some of you found alarming: You are an ape. That column addressed some common misconceptions about how humans emerged in response to a question about evolution: "Why aren’t apes evolving into humans?" There's a simple answer: Humans did not evolve from chimpanzees or any of the other great apes that live today. We instead share a common ancestor that lived roughly 10 million years ago. Asking why modern chimps don't look more like humans is like asking why the children of your cousins don't look more like you than their parents. They're on an entirely different evolutionary path. But based on many of the emails we received (and the number of new queries
Want to find some ancient fossils? Scratch yourself. Many of the genes in our cells evolved billions of years ago and a few of them can be traced back to the last common ancestor of all life. Now we have the best picture yet of what that ancestor was like and where it lived, thanks to a study that identified 355 genes that it probably possessed. “It was flabbergasting to us that we found as many as we did,” says William Martin of the University of Dusseldorf in Germany, who led the study. The findings support the idea that the last universal common ancestor (LUCA) lurked in hydrothermal vents where hot water rich in hydrogen, carbon dioxide and minerals emerged from the sea floor. “It’s spot
露卡(Luca，The Last Universal Common Ancestor)，即所有物种在分化之前最后的一个共同祖先，也就是地球上生命的起源。
Four billion years ago, sometime around Earth's 560 millionth birthday, Luca was born. Luca is your great-to-an-infinite-degree grandmother and grandfather, as it is your dog's and your goldfish's and your ficus'. Every living thing on earth owes it existence to Luca, whose very name stands for "Last Universal Common Ancestor." It is the origin of life of earth, from which the rest of us evolved. And now scientists believe they have mapped a genetic picture of the qualities that would have belonged to Luca, giving us a startling look at how life on earth might have began: ...By comparing their sequence of DNA letters, genes can be arranged in evolutionary family trees, a property that enabled [Dr. William F.] Martin and his colleagues to assign the six million genes to a much smaller number of gene families. Of these, only 355 met their criteria for having probably originated in Luca, the joint ancestor of bacteria and archaea. Genes are adapted to an organism's environment. So Dr. Martin hoped that by pinpointing the genes likely to have been present in Luca, he would also get a glimpse of where and how Luca lived. "I was flabbergasted at the result, I couldn't believe it," he said. The 355 genes pointed quite precisely to an organism that lived in the conditions found in deep sea vents, the gassy, metal-laden, intensely hot plumes caused by seawater interacting with magma erupting through the ocean floor. [The New York Times ] Chemist John Sutherland, of the University of Cambridge, has a rival theory that life formed in shallow pools, not the ocean. Others say that Dr. Martin's version of Luca is actually the sophisticated descendent of someother original Luca. But regardless of which theory you believe, as James O. McInerney wrote in a commentary about Dr. Martin's research, Luca is "a very intriguing insight into life four billion years ago." Read all about itat The New York Times .▶Full story on theweek.com
