1.   But no one knows why the vomeronasal organ should have two detection systems.

2.   Dulac said the vomeronasal organ might have atrophied in higher primates as they came to rely on sight to tell males and females apart.

3.   One group was allowed to sniff synthesized pheromones that are said to act on the vomeronasal organ in the nose.

4.   Over the years, many people have suggested that this so-called vomeronasal organ detects pheromones, but researchers say there is no solid evidence of that.

5.   Scientists have long wondered whether human behavior, too, is influenced by pheromones, because people possess a vomeronasal organ.

6.   The nose has another sensory structure, called the vomeronasal organ, which is specialized for detecting pheromones.

7.   The story has taken another twist with the discovery that the vomeronasal organ possesses a second set of odor receptors, again with its own family of genes.

8.   There seem to be no neurons in the human vomeronasal organ, and the genes that make its critical parts have mostly decayed by natural mutation into nonworking forms.