Posted on Jan 21, 2018 in Astrobiology, Astronomy, Biology, Science
There’s a black hole in the middle of the history of life: how did we go from tiny bags of chemicals to the vast menagerie of creatures we see around us? RadioLab explores one of the most underrated mysteries of all time, and present one possible answer that takes us from an unexpected house guest to a tiny bolt of lightning to every critter you hold dear. It’s the story of one cosmic oops moment that changed the game of life forever.
Shortly after Earth’s formation, the planet was barren of life. Then, proteins combined in just the right way, and life appeared. For billions of years, it was simple and uninteresting, oceans full of simple, single-celled organisms floating for millennia after millennia.
Suddenly, life got a lot more interesting. Organisms became more complex, with more than one cell. And they got much bigger — 10,000 times bigger by volume, Nick Lane, professor of evolutionary chemistry at University College London, wrote in his 2015 book The Vital Question.
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The importance of this step — of this sudden increase in size and complexity — cannot be overstated. Without it, complex life (like humans, for example) would not exist.
How exactly this step happened is one of the big questions in evolutionary biology. There are a number of theories about how, exactly, life got so much more complicated. One of the prevailing theories, from Lane himself, focuses on energy. Here’s the thinking: Cells need more energy to build more complex structures. To do that, according to Lane’s theory, single-celled organisms merged with bacteria we now know as mitochondria, which have an electrical charge and bring power to the cell. It’s possible, though unlikely, for the two bacteria to fit together, and even less probably that the two were able to survive and live symbiotically. This occurrence that made possible all other forms of complex life is rare, to be sure.
But in Lane’s opinion, it only happened once.
“It comes down to one merger between two cells that made one cell, then everything comes from that. You, me, the redwood tree or the hummingbird, a fungus, a piece of algae growing in a pond, every form of life we can see with our naked eyes and many that we can’t come from that single cell,” Nick said in an episode of the science podcast Radiolab on his work.
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The Daily Galaxy via Futurism, and RadioLab and Nautil.us