Man's best friend

Dogs, always saving our collective asses.

The biological basis of the astonishing variety of behaviors of man's best friend is a big step closer to comprehension today with the publication of the dog's genome -- its 2.41 billion nucleotides, or DNA "letters."

The dog -- in the form of a female boxer named Tasha -- joins the human, the chimpanzee, the mouse and the rat on the list of mammals whose genetic instruction manual has been transcribed. The genomes of the fruit fly, a microscopic worm, yeast and several bacteria have also been decoded.

But the dog genome is far more than a curiosity. It is already providing insights into evolution and will probably make dogs the chief tool for understanding the genetic diseases of people.

Certain breeds are at much higher risk than others for specific ailments. Samoyeds have a tendency to become diabetic, Rottweilers develop the bone cancer osteosarcoma, springer spaniels are at risk for epilepsy, and Doberman pinschers suffer from narcolepsy much more often than other canines. All these diseases have human counterparts.

"This offers a strategy for tracking down the location of genes involved in medical conditions that in the past we have just not been able to tackle," said Francis S. Collins, director of the National Human Genome Research Institute, which helped pay for the work.

Eric S. Lander, director of the Broad Institute in Cambridge, Mass., where the research was done, said: "The genetic structure of dog breeds is so much clearer than in the human population that it will make genetic analysis much simpler."

I would like to suggest, however, that those who continue to say that evolutionary biology is "just a theory" not be allowed to take advantage of any fruits of this advance.