Siegelgale conducted months of interviews with leaders, people in the field, and customers -- in this case, the girls and their parents. At the same time, the consultants sifted for images that spoke to the girls: the Disney film Mulan, a movie that told the story of a young girl going to war to protect her family; the Women's National Basketball Association; and the popular TV show Buffy the Vampire Slayer. "All of those images showed girls in control, girls in power, girls center stage and on the court -- not on the sidelines," says Linda Cornelius, managing director of Siegelgale's New York office. "The message was, it was cool to be strong."

That message was already embedded within the Girl Scouts' DNA. "The Girl Scouts have a law," says Cornelius. "It says, 'I will do my best to be honest and fair, friendly and helpful, considerate and caring' -- all of the things that people generally associate with scouting. But that same line continues with the words, 'courageous and strong.' When we saw those attributes, we said, That's it! That's the part of the Girl Scouts that the girls don't get credit for." Siegelgale had the new mantra of the branding campaign: The Girl Scouts was the place "where girls grow strong."

Find a Look That Fits

Many companies talk about how their people are the best advertisement for their values. At the Girl Scouts, it's true. The new brand had come from the seeds of the organization. Now the new look would come from its members. "We were very keen on getting the word directly from the girls," says Evans. "They are our customers."

What the customers wanted came down to one word: khaki. "No matter what style," Evans says, "the girls told us over and over. They're not wearing it unless it's khaki."

The process of creating the new look was like a time-lapse version of natural selection at work. Staff designers fanned out from Girl Scouts headquarters on Fifth Avenue in New York to the major stores in Manhattan, returning with bags of samples. They scanned the different designs and quickly selected the most popular styles and colors with an eye to what would be most practical for the Scouts. Guided by national director of equipment service Kathleen Duncan, who had spent 20 years as a buyer and fashion director before joining the Girl Scouts, the team created its own patterns: a couple of styles of slacks, shorts, blouses, and skirts.

The final products could have been in the window displays of the finest shops in any mall in America: new A-line skirts that ended well above the knee; parachute-style cargo pants; stretch-fabric navy tops. The entire color scheme underwent a transformation from dark green to khaki with pastel blue for Senior Girl Scouts and khaki with jade green for Junior Girl Scouts. The only feature that identified the wearer as a Girl Scout was a discreet rectangular label -- the kind that comes automatically on any Tommy Hilfiger outfit.

The girls went wild. In city after city, at focus groups convened by Siegelgale to test the designs, scouts raved about the new look. "Girls told me that this was the first uniform they would consider wearing with their friends at school," Evans says.

But true to the laws of natural selection, the new uniforms are a reminder that every adaptation carries the seeds of the next one. In an environment where all outfits are khaki, will the Girl Scouts stand out enough to be distinctive? "It's a balancing act," says Evans. "The uniforms have to look hip without straying too far from the conventional standards. But if they're dorky and the girls don't like them, they won't wear them. Now at least we've got a look that girls feel proud to put on."

Paul C. Judge (pjudge@fastcompany.com) is a Fast Company senior editor.

Sidebar: Lessons of Adaptation

"This preservation of favourable variations and the rejection of injurious variations, I call Natural Selection," wrote Charles Darwin in The Origin of Species. In the world of business, what does adaptive behavior look like?

Successful adapters see the world with fresh eyes. When the environment shifts around them, they are among the first to respond to changes in the complex web of relations that binds together all species. As Darwin pointed out, competition is keenest between closely allied forms in nature. Successful adapters are quick to differentiate themselves from their closest rivals.

Speed matters. Adapters are often quicker to locate and exploit new sources of nutrition. They find ways to coexist where possible and to outrun, outmaneuver, or outfight competitors where necessary. When landscape-altering events sweep across the environment, some species win simply by making do with what's at hand. Efficiency can be the best survival strategy.

Instinct plays a crucial role. All species possess instinct. But successful adapters seem to have a more refined capacity to intuit the dangers and opportunities in their environment and to act decisively. Darwin, who considered instinct to be a powerful, mysterious force, wondered where it comes from. Without presuming to answer the question, he demonstrated how natural selection works to refine instinct in such cases as slave-making ants or hive-making bees. However species come by instinct, they can't last long without it.

Adaptation is never over. Conditions change constantly in large and small ways, demanding and favoring ongoing adaptations from species -- and companies. Natural selection, wrote Darwin, "is a power incessantly ready for action."