Designer dog noses excel at scent identification, according to Nature Science Update 7 April 2003. Researchers at Tufts University, Massachusetts USA, have built a replica of the internal structure of a dog’s nose, basing their design on scans of a real dog’s nose and lining it with electronic sensors connected to a computer. The computer was able to identify smells more accurately if the air passed through the artificial nose rather than over a single sensor, as in already existing chemical sensing devices – but why?

Dog noses (and other mammal’s) contain a maze of air passages lined with cells sensitive to chemicals in the air. Most smells are combinations of differing chemicals so each smell is detected by a mix of cells in different places along the passages. Chemical sensor cells send electrical signals to the brain, which interprets the varying patterns of signals as different smells. Sending air through twisting maze-like passages helps produce a distinctive signal pattern for each smell, making it easier for the brain to identify the source of the smell.

Editorial Comment: When their experiment to copy dog nose structure by intelligent planning and use of clever technology worked, these researchers were using a creationist thought framework rather than an evolutionary one. The concept that the maze like internal structure of a dog’s nose helps the dog identify scents, comes from a creationist mindset that says biological structures have plan and purpose. (Ref. nose, dog, design)