In my new podcast I take a look at Darwinian agriculture–how farmers can improve their crops by taking advantage of evolutionary history. I talk to Ford Denison of the University of Minnesota, who has done fascinating work plants such as soybeans and the bacteria that live in their roots and supply them with essential nitrogen. It’s a complicated relationship, full of cooperation, conflict, cheating, and punishment. Check it out.
Originally published May 19, 2010. Copyright 2010 Carl Zimmer.
Less than two percent of the human genome is made up of protein-coding genes. Fifty years ago, scientists launched an expedition of the other 98 percent. It has been a slow march for much of that time, but in recent years the pace has picked up, thanks to advances such as new ways to sequence DNA.
My newest column for Discover is about that strangest of the senses, smell. An odor can be an overwhelming experience, and yet it’s often impossible to put that experience into words. In fact, we’re terrible at naming smells, despite being exquisitely sensitive to the differences between them. I take a look at some recent research that may bring us closer to resolving this paradox, with the invention of the first yardstick for the nose–a simple measurement of odor molecules that reveals a lot about how pleasant or vile we find them. Not only might it help us understand our own noses, but it may even let us build electronic noses to sniff for things we don’t want to stick our own noses in. Check it out.
Originally published May 18, 2010. Copyright 2010 Carl Zimmer.
Elizabeth Kolbert writes this morning about the Anthropocene, a new geological epoch marked by the dominance of our species. It may be hard to precisely mark its beginning, but here’s why I think it will be easy for geologists 10 million years in the future to pinpoint layers of Anthropocene rocks.
Originally published May 17, 2010. Copyright 2010 Carl Zimmer.
Discover, May 17, 2010
Your nose is a paradox. In some ways the human sense of smell is astonishingly precise. For example, natural gas companies add a smelly molecule called n-butyl mercaptan to natural gas, which is odorless by itself, so that people can sniff gas leaks. All it takes is one n-butyl mercaptan molecule for every 10 billion molecules of methane to do the trick. To put this precision in perspective, imagine you are standing in front of two Olympic-size swimming pools. One of them contains a grand total of three drops of n-butyl mercaptan, and the other has none. Your nose could tell the difference.