It must have been evening when the woman with pearly white fingernails shimmied past some of the older people in the front row and settled down to hear the end of the service. I remember falling a little bit in love with her and her tailored blazer, ivory blouse, black pants, pointed kitten heals in green snakeskin. Mostly I remember her nails, folding her program, reaching into her bag, flipping her hair out of her face. I was sitting two rows behind her, and I do not remember whether my own nails had anything on them, but if they did, it was certainly not fresh or becoming. It was probably weeks-old polish chipping off in flakes of some insistently adolescent color. These would rest below the chairs for weeks, impervious to vacuums.

Natural ornamentation is a staple of evolutionary theory. In 1871, Darwin published The Descent of Man, in which he explained that though people often think that sensitivity to beauty is peculiar to man, it is not. “When we behold male birds elaborately displaying their plumes and splendid colours before the females, whilst other birds not thus decorated make no such display, it is impossible to doubt that the females admire the beauty of their male partners.” As might be expected, Darwin believed that ornamentation had evolved for the purpose of natural selection—that is, for the purpose of sexual attraction to biologically worthy members of the opposite sex.

Anthropologists believe that deliberate ornamentation, self-conscious beautifying with non-bodily objects, is unique to the genus Homo, although it precedes Homo sapiens. The earliest known jewelry is from the Paleolithic Era, when our ancestors stood upright, used tools, and lived together in communities, but had skulls that were still distinctly non-human. Once those rounded out into the half-spheres we know today, and civilization began in earnest, many relics of decoration were lost to be found again by modern archeologists. Jewelry of all kinds has been excavated that once belonged to the earliest human communities. Maquillage left behind fewer artifacts, but archaeologists have unearthed evidence of that more impermanent variety of purposeful adornment from communities across Europe, the Middle East, and Asia. They speculate that it was just as ubiquitous a form of purposeful adornment.

Darwin believed that human evolution continues to follow the principle of natural selection. Those who continue to subscribe to his view say that deliberate human ornamentation simply took that principle to a more self-conscious, culturally informed level—what some older anthropologists call “runaway sexual selection.” According to these anthropologists, culturally specific ornamentations that at first appear several steps removed from “natural” sexual desirability—lip plugging, neck elongation, foot binding, for example—are just more complex and idiosyncratic markers of the worth of potential mates.

Others disagree. The farther from evolutionary biology and the deeper into the modern anthropological field one gets, the more insistent certain scholars become that there is something unique about human ornamentation. The culturally specific aspects of ornamentation differ markedly among societies, indicating that there is a communal element to the impulse to beautify that reaches beyond Darwin’s ever-individualistic principle of survival of the fittest. As Camilla Power explains in an essay called “Cosmetics, Identity and Consciousness,”one wearing cosmetics in a particular cultural context asks not only “‘Who am I? and ‘How do I look to the others?’, but also asserts: ‘This is where I belong in the cosmos’ in relation to those others.” In fact, Power points out, cosmetics and cosmos are easily discernable linguistic descendants of the same Greek root, kosmos, meaning adornment or arrangement. “The decorated body,” she writes, “becomes both art object and organizing subject in kinship-based, self-organizing societies.”

Human hands (like the ones that held the program, glittering) have been a platform for ornamentation for thousands of years. Nail coloring in particular was widespread in the ancient world. Egyptians, for example, used henna dye to stain their nails various shades of orange. In Turkey, women boiled rose petals to create a pink tint for the nails, and in Rome people painted their nails using a mixture of blood and sheep’s fat. In China, during the second millennium BCE, both men and women in the upper class grew their nails to impractical lengths, sometimes to ten inches. Some would protect these talons in gold sheathes inlaid with jewels. Others would paint them with a black dye made of egg whites, beeswax, vegetable dyes, and Arabic gum. Later, during the Zhou dynasty, nobles wore artificial nail strips made with gold and silver dust.

Given this whirlwind of ancient chemistry from such different locations, we might think to ask, why nails? Nails’ hard, visible surfaces are intuitive contenders for cosmetic enhancement, especially in light of the fact that for the anthropomorphic impulse to cosmeticize, the bar is not very high. If there is a way to adorn it, humans will. There is even more of an impulse to cosmeticize when that ornamentation can be culturally specific but only selectively available. In other words, if humans can find a way to differentiate between classes, they probably will. It was only the Chinese nobility that could afford to be incapacitated by those long nails. In ancient Babylon, there was an analogous class implication of the color a man could afford to paint his nails. A more speculative reason given for why a whole variety of cultures cared to cosmeticize their fingertips is that certain cultures believed that nails continue to grow after death. The dehydration of a corpse causes the skin around the nails to retract, creating the eerie illusion that the fingernails of the deceased body are extending. Given this symbolic association with nails, anthropologists hypothesize that healthy, accented nails in life may once have been considered a symbol of immortality.

Whatever the reason for the focus on nails, there seems to have been a plateau in polish development for several thousand years. The thread in beauty encyclopedias picks up in the 1800s in the United States, where clean, unstained hands were linked with good hygiene and moral purity, and women apparently used lemon juice or vinegar to whiten nail tips. The purer the nails, the less work a woman had done, maintaining the class distinctions that were signaled by some ancient cosmetics.

The commercial business of nail polish started in earnest in the 1920s. The technology that was used to manufacture car paint was adapted to fingernail polish. Original colors were created to complement shades of lipstick: pinks, reds, corals, peaches. In the thirties, nail lacquer became opaque, and the innovator, Charles Revson, started Revlon, Inc., still prominent today. The recipe has been tweaked, but since the early twentieth century, the constituent elements—and with them, the concept of the modern manicure—have remained largely constant.

With that consistency has come democratization. Nail polish is now widely available at every possible degree of extravagance. Though there are certainly distinctions in the style and quality of various brands, almost anyone can afford a bottle of nail polish. (With my first ever allowance of pocket money, $4, I bought a can of Fresca and a bottle of drugstore polish.) In the United States and other developed countries, the nail polish market is by no means the largest cosmetic industry, but in 2015 (the year with the most recent available data), the market size of bottled nail polish alone was $930 million. According to the industry statistics given by Nails magazine, Americans spent $8.51 billion on nail services that year, beyond that.

Nail colors, available in every hue in the spectrum, circle in and out of style like other accessories. Harper’s Bazaar calls for pastel green, powder blue, vibrant grape for spring 2019. Next to a bottle of swirling, lustrous lavender, they assure the reader that “holographic nails aren’t going anywhere—and we’re here for it.” Fashion magazines recommend the next season’s colors and quote celebrities on their favorites. When I was in seventh grade, black was “in,” and, like all the other girls, I came home from a manicure birthday party with inky black nails. My Dad had me promptly remove it, and I smoldered over the smell of acetone on my bathroom floor. There also seems to be an unspoken rule among fashionable brands that the colors must be named preposterously. Essie, one popular brand of nail polish in the United States, gives colors names like “wire-less is more,” “cause and reflect,” and “salt water happy” (lower-case names are a part of the branding, apparently). O.P.I, another popular brand, calls colors names like “Butterfly Me to the Moon,” “Ecstatic Prismatic,” “Metamorphically Speaking.” Although salt water happy is a shade of light blue, which half works, the rather questionable wordplay is often unrelated to the actual color of the polish.

Only occasionally will you see a clever name, but that is part of the point. Cosmetics today in America are insulated from analysis. Time and research surely go into choosing products, but cosmetics are used, a means to an end, clearly not seen as the modern iteration of a human tradition from prehistoric times. The point that anthropologists make is that human self-ornamentation is directly related to the building of societies, but rarely do we consider that the way we decorate ourselves today is built into the societies we live in simply by virtue of our heritage as members of our species. The underlying reasons that we cosmeticize ourselves are generally relegated to that one time you almost listened to your mom when she said that you looked beautiful without makeup, too.

There is, of course, no sin in forgoing personal interaction with the intellectual history of maquillage. Doing so might actually take away the fun in choosing a nail color because it is called “good knight” and you found that clever enough to smirk at. But I puzzle at why I remember that woman and the pearls at the tips of her fingers so well. I guess I somehow felt it: the symbolic, organizing power of relative presentation. Her nails – those pearly white nodes of grace – were telling me something.