As Fashion Week winds down in New York, scientists continue their own search for the very latest in ancient fashion—latest meaning oldest. They're asking one seemingly simple question: Who invented clothes anyway?

As straightforward as it sounds, it isn't easy to answer. We may be used to artistic depictions of prehistoric Homo sapiens and Neanderthals wrapped in furry hides, but, in truth, the story of how clothing became such a prominent mark of humanity is only just starting to be unraveled.

Clothing doesn't readily fossilize. Much like the soft tissues that wrap our bones, fabrics and other body coverings decay rapidly. Yet, despite this, archaeologists and anthropologists are starting to figure out the elements of prehistoric style through an array of indirect evidence that includes everything from dyed plant fibers to lice.

The Dawn of Fashion

According to Université Bordeaux archaeologist Rebecca Wragg Sykes, the oldest garments archaeologists have found are all relatively young. There are 8,000-year-old bark sandals from Oregon, a shirt and beaded dress made about 5,000 years ago in Egypt, and the clothing of Otzi—the 5,000-year-old "Ice Man"—who wore leather and woven grass shoes, a fur jacket, leather leggings, and even leather underwear.

But Wragg Sykes says that "if you accept that clothes are pretty delicate things and will be preserved intact extremely rarely, then you can look for other evidence of their presence during more ancient times."

She says that ancient burials, for instance—like a 28,000-year-old Homo sapiens grave in Sungir, Russia—"record the ghosts of garments" in the form of beads and teeth that must have been part of clothing.

But burial wear wasn't the day-to-day coverings of these people. The record on prehistoric daily wardrobes is sketchy, but Wragg Sykes has pointed to a suite of indirect evidence that people were creating clothing tens of thousands of years ago.

Dyed plant fibers—pink, black, and blue—from a 30,000-year-old cave site in the country of Georgia hint at early fabric-making. Delicate, 20,000-year-old bone needles were likely used to create clothing and jewelry.

Contrary to artists' depictions showing prehistoric people in rough furs only, Wragg Sykes says the archaeological record is clear that people were making much more complex clothes by 25,000 years ago.

Both stone tools and lice, respectively, take the possibility of clothes back even further.

"Toolkits dominated by stone scrapers become more commonplace in Europe and southern Africa beginning around 300,000 years ago," says Australian National University's Ian Gilligan, who has published studies of prehistoric clothing. Overall, he says, "the relative frequencies of these hide-working tools [is] correlating strongly with colder climatic fluctuations."

Then there's the lice. A 2011 study found that lice that live on clothing have a genetic trail going back to between 83,000 and 170,000 years ago.

Neanderthal Style

Prehistoric Homo sapiens wasn't the only species of human to wear clothing, though. Our close Neanderthal relatives undoubtedly did, too.

In art and even anthropology, Neanderthals have often been derided as cruder versions of ourselves. A famous 1909 illustration of a Neanderthal depicted a naked, hairy, exceptionally ape-like human, and even more modern restorations sometimes show these people with tattered, haphazardly created animal skins dangling off their bodies in what our modern eyes perceive as the barest attempt to be modest.

But there are some clues that Neanderthals were doing far more than throwing on smelly skins. From microscopic wear patterns left on their tools, Wragg Sykes says, there's a good indication that Neanderthals took care to prepare clothing.

"There is one tantalizing indication that they were tanning leather about 100,000 years ago," Wragg Sykes says: "organic scraps—left on a stone tool from Neumark Nord in Germany—that contain high levels of tannin from an oak that was present during this warm phase."

There are also biological reasons to think that Neanderthals covered up.

In a 2012 study, University of Connecticut anthropology graduate student Nathan Wales attempted to reverse-engineer what sort of clothing Neanderthals would have worn.

After surveying the clothing of 245 non-prehistoric hunter-gatherer cultures and the environmental conditions in which they lived, Wade hypothesized that Neanderthals inhabiting especially cold Ice Age regions would have covered up to 80 percent of their body surface with "non-tailored clothing."

Modern humans, by contrast, were expected to be less cold-tolerant and to bundle up against winter chills with more carefully crafted clothing.

This supposed difference in clothing culture has even played into the persistent—and still unresolved—question of why Homo sapiens survived and Neanderthals (in their anatomy and culture, since many of us carry Neanderthal genes) died out.

In a 2007 review, anthropologist Gilligan suggested that Neanderthals were biologically better able to withstand the cold and therefore had less reason to develop sophisticated garments to stay warm. "Their superior physical cold tolerance, however, meant less need for behavioral cold adaptations," Gilligan says.

Clothes Make the Man?

The need of our species to shield ourselves from the chill, Gilligan hypothesizes, led us to develop the technologies and artistic culture to produce comfier clothing. Thus our species was technologically flexible enough to cope with painfully cold temperature spikes of the Ice Age, the idea suggests, whereas the Neanderthals were not so prepared.

But Wragg Sykes doesn't find the argument especially convincing.

"I think the distinctions drawn between Middle and Upper Paleolithic clothing in terms of insulation are overstated, as they're based on very little actual evidence," Wragg Sykes says, referring to the Middle Paleolithic culture of the Neanderthals and the Upper Paleolithic culture of our species.

"I can't see that Neanderthal clothing would have specifically hindered them more than contemporary H. sapiens in regard to a fluctuating climate," she says.

Wales agrees, noting that "Neanderthals lived in a range of habitats, including relatively temperate environments where minimal clothing would be required."

Wales continues, "In these environments, differences in clothing would probably have little to no effect on the survival of the species."

We still don't know what Neanderthals—or even modern humans of the time—wore, and because Neanderthals became anatomically extinct, we have a tendency to look back at them as if they were inferior.