Women See This One Color Differently

She sees crimson, burgundy, and tomato. He sees red. Just plain ol' red. Why?

It turns out there's a perfectly good reason why men can't see what is so obvious to women: the many variations--some subtle, some bold--of the color red.

Reuters reports that researchers from Arizona State University in Tempe have determined there is a gene that allows us to see the color red, and that gene comes in a high number of variations. Because the gene sits on the X chromosome--and women have two X chromosomes and so two copies of this gene, compared with only one for men--the gene aids women's ability to perceive the red-orange color spectrum.

The Arizona researchers, led by Dr. Brian C. Verrelli and Dr. Sarah Tishkoff, analyzed the DNA of 236 men around the world and learned that the gene OPN1LW, which allows us to see the color red, has at least 85 variations--three times the number of variations you would expect to find in any other gene randomly selected from the human genome.

It turns out that these variations, which have been preserved throughout evolution, are beneficial. The researchers speculate that it all began in our cavewoman days when sharp color perception was useful to women when they gathered and foraged for food. The crimson berries may have been poisonous, while the burgundy berries were just fine.

Here's an interesting tidbit: The "red" gene routinely swaps bits of genetic material with the neighboring "green" gene that also sits on the X chromosome. Reuters notes that sometimes this exchange goes wrong and results in a defect that causes colorblindness. An estimated 8 percent of men are colorblind. Very few women suffer from this since they have two copies of the red and green color genes, and at least one of them tends to work correctly.

The study findings were reported in the American Journal of Human Genetics.

News, Photo and Web Search