Never underestimate a mole.
It’s easy to have low expectations for these creatures. My own experience with moles is limited to the sight of their carcasses at my doorstep, laid there by our triumphant and generous cat. Stretched out on the cold bluestone, they look like little more than eyeless pouches of fur.
The New York Times, February 4, 2013
In 1855, Charles Darwin took up a new hobby. He started raising pigeons.
In the garden of his country estate, Darwin built a dovecote. He filled it with birds he bought in London from pigeon breeders. He favored the fanciest breeds — pouters, carriers, barbs, fantails, short-faced tumblers and many more.
“The diversity of the breeds is something astonishing,” he wrote a few years later in “On the Origin of Species” — a work greatly informed by his experiments with the birds.
In tomorrow’s New York Times, I write about what pigeons taught Darwin about evolution, and what they can teach us over 150 years later. The spur for the story is a new paper in which scientists analyze the genomes of forty different pigeon breeds to understand the molecular secrets behind their remarkable diversity. My story is accompanied by some wonderful photos as well as a podcast in which I talk to my editor, David Corcoran, about the research.
Discover, January 30, 2013
Ten thousand years ago, there were just 5 million people on Earth, fewer than live in Singapore today. The population has since soared to 7 billion. This rapid growth has left a mark on the human genome, researchers are finding, drastically increasing the number of very rare mutations in our DNA. That realization casts doubt on the long-standing view that just a few genetic mutations underlie many hereditary diseases. In reality, those diseases are probably caused by a wide variety of extremely rare mutations that vary from one person to the next, complicating efforts to understand and treat them at the genetic level.
We’re made of parts. Our skull is distinct from our spine. Our liver does not grade subtly into our intestines. Of course, the parts have to be connected for us to work as a whole: a skull completely separated from a spine is not much good to anyone. But those connections between the parts are relatively few. Our liver is linked to the intestines, but only by a few ducts. That’s a far cry from the intimate bonds between all the cells that make up the liver itself, not to mention the membrane that wraps around it like an astronaut’s suit. The distinctness of the parts of our bodies is reflected in what they do. In the liver, all sorts of biochemical reactions take place that occur nowhere else. Our skull protects our brain and chews our food–jobs carried out by no other part of our body.
Biologists like to call these parts modules, and they call the “partness” of our bodies modularity. It turns out that we are deeply modular. Our brain, for example, is made up of 86 billion neurons linked together by perhaps 100 trillion connections. But they’re not linked randomly. A neuron is typically part of a dense network of neighboring neurons. Some of the neurons in this module extend links to other modules, creating bigger modules. The brain can link its modules together in different networks to carry out different kinds of thought.
