Over on Facebook, David Hillis, an evolutionary biologist at the University of Texas, took up my question as to whether anyone can define life in three words. His short answer was no, but his long answer, which I’ve stitched together here from a series of comments he wrote, was very interesting (links are mine):
Continue reading “Life with a capital L? (Like Zimmer with a capital Z?)”
I’ll be on National Public Radio’s Science Friday this week to talk about Science Ink. Host Ira Flatow and I will be chatting during the 3 pm EST hour. In the meantime, the folks at Science Friday have set up a slide show preview.
Originally published January 11, 2012. Copyright 2012 Carl Zimmer.
Today , a company called Ion Torrent announced they were going to start selling a DNA-sequencing machine that can sequence an entire human genome for $1,000. It’s just the latest milestone in the long-term crash in the cost of gene-reading. There are lots of benefits that will flow from this ongoing transformation. For one thing, as I wrote in 2010 in the New York Times, it’s getting easier to identify new viruses that could turn to be the next HIV or SARS.
This is a story of about how the parts of a puzzle locked into place 800 million years ago. The puzzle is an ion pump that you can find in any mushroom, mold, or yeast. I’ve reproduced a picture of it here.
Fungus cells, like our own cells, have lots of little pouches inside of them for carrying out special kinds of chemical reactions. In order for those reactions to work, there have to be a lot of positively-charged protons inside the pouches. To get those protons into the pouches, ion pumps like this one force them through membranes.
Continue reading “Resurrecting Evolution to Solve an 800-Million-Year-Old Puzzle”
Txchnologist, January 10, 2012
In November 2011, NASA launched its biggest, most ambitious mission to Mars. The $2.5 billion Mars Science Lab spacecraft will arrive in orbit around the Red Planet this August, releasing a lander that will use rockets to control a slow descent into the atmosphere. Equipped with a “sky crane” (NASA’s official, and very cool, term), the lander will gently lower the one-ton Curosity rover on the surface of Mars. Curiosity, which weighs five times more than any previous Martian rover, will perform an unprecedented battery of tests for three months as it scoops up soil from the floor of the 96-mile-wide Gale Crater. Its mission, NASA says, will be to “assess whether Mars ever was, or is still today, an environment able to support microbial life.”