College of LAS « Illinois

Animal Biology

Guppies Show That Variety Is the Spice of Life


Fitting in is overrated; there are perks to being unique. Scientists discovered that male guppies with colorful—and the most rare—patterns are more likely than their more commonly colored counterparts to survive in the wild.

"This study provides very solid support for frequency–dependent survival," says principal investigator Kimberly A. Hughes, an animal biologist in the College of Liberal Arts and Sciences and lead researcher for the six–institution project. "We found that rare color patterns of these guppies had a highly significant survival advantage."

Frequency–dependent survival means that individuals with rare gene variants have a survival advantage relative to common variants, simply as a function of being rare.

This process is important because it leads to the maintenance of many different variants (polymorphism) in the same population, including the maintenance of genetic variants in humans, says Hughes, who is also a member of the Institute for Genomic Biology at Illinois.

It has been hypothesized that genes involved in pathogen resistance are highly polymorphic because pathogens are most successful at attacking individuals with common variants, and individuals with rare variants have higher survival.

Similarly, "it's possible that guppy predators, which are known to hunt visually, may be more focused on common color patterns…and can be less efficient at locating and capturing prey that look different from the norm," Hughes says.

Details of the scientists' research were reported in the June 1 issue of the journal Nature.

Fall/Winter 2006–07