Theoretical origin of life; another take (Introduction)

by David Turell , Monday, April 27, 2015, 20:36 (3498 days ago) @ David Turell

This time a book that proposes deep sea vents, hot and acidy, with a proton pump at the beginning. Amino acids don't work in that climate, and thre are many other problems the book discusses:-http://www.newscientist.com/article/mg22630180.600-the-vital-question-finding-answers-about-the-origin-of-life.html#.VT6S8GB0y1u-"Lane has been developing a grand vision of where and how life began, and why it evolved in the way it did. What's more, he thinks the "gene-jocks" will never answer these questions by studying genomes and the like. Instead, we need to focus on what drives life: energy.-"Living cells are powered by a totally unexpected process. The energy from food is used to pump protons across a membrane to build up an electrochemical gradient. This gradient drives the machinery of life, like water from a dam driving a turbine.-"And Lane argues that life has been powered by proton gradients from the very beginning. Forget all those primordial soups or "warm ponds": only the natural proton gradients found in undersea alkaline hydrothermal vents could have provided the continuous flux of carbon and energy that life requires. These vents may be common on rocky planets so, if this reasoning is correct, simple cells should be too.-"It's the next step that is tricky. To become more complex, cells need more membrane to provide more energy. But the larger the area of membrane, the harder it is to keep control of the proton gradient - and losing control means death. So cells stayed simple. "There is no innate or universal trajectory towards complex life," Lane writes.-"Not, at least, until something extraordinary happened: one kind of simple cell somehow started living inside another. Eventually, the first cell turned into the self-contained energy-producing structures we call mitochondria. This Russian-doll arrangement meant cells could get more energy simply by making more mitochondria, allowing them to become much larger and more complex."-Turning into a mitochondrion is not an easy trick. Where did the DNA come from in the organelle? It is all fun and games.