(HOST) When commentator Dan Rockmore thinks about summer hikes, he thinks about dogs. But being a mathematician, he also thinks about genetics and probability.
(ROCKMORE) Recently, I received a phone call from my old friend, Tim, a former colleague of mine here in the math department at Dartmouth, now teaching at the University of Florida.
Tim called me with the most extraordinary story – his dear old dog, a beautiful golden retriever named Charlie, had just turned up at the local humane society – after having been missing for 7 years!
Charlie and Tim were reunited by way of a tiny piece of information: a microchip that had been inserted just below the skin in the back of Charlie’s neck, many years ago.
Charlie was wandering along the side of a road when he was picked up by the Florida humane society. He was partially blind and deaf, and no longer of interest to the people who had stolen him. When the society scanned Charlie’s neck, they found this microscopic piece of identification and with it, were able to trace Charlie back to Tim.
Now, this is a great story, but to be honest, it’s a little bittersweet for me. You see, Charlie’s brother, Digger, was my dear old dog. They were both born in the shadow of Mt. Ascutney 14 years ago this summer, and then raised in Hanover, where they came to be known as "the boys" and they lounged around the departments of mathematics and computer science at Dartmouth College.
Digger died almost 4 years ago of cancer of the liver. We had taken a summer hike to the top of the tallest peak in the Santa Fe National Forest – Digger and Dan on another of their many mountain adventures, unaware that it would be their last. Digger faltered on the way down and I carried him off the trail and rushed him to the vet. Surgery revealed that Digger was shot through with cancer, and there was nothing to done.
Now, Charlie and Digger had the same parents, and thus, almost entirely the same genome, a long molecule neatly summarized as a sequence of letters of A’s, C’s, G’s, and T’s. Embedded in this genetic code are the instructions by which an organism comes into being – a recipe for cooking up a creature — cell by cell .
Because they were twins, Digger and Charlie’s genomes probably only differed by the smallest bit of information – surely less than one tenth of one percent. But in that tiny difference lay the roots of a difference in development – one that presumably made Digger more susceptible to the scourge of cancer, but one that also made him the puppy that I had to have that glorious morning in Ascutney fourteen years ago, as well as the beautiful, sweet dog that barely left my side for ten years. And as Tim’s call reminded me, sometimes just a little information can make all the difference.