In 1913, William Matthews Flinders Petrie was frustrated.

While leading excavations at the cemetery of Tarkhan in Egypt, his curiosity had been piqued by a nearby tomb.

After finally getting the tomb open, Petrie was disappointed to find that it had been completely emptied, except for five calcite jars, two wooden tool handles, a small pot lid, and a pile of dirty linen.

But within this pile was an extraordinary find, one that would not be recognized for over 60 years.

In 1977, museum conservators looking through Petrie’s “dirty laundry” would find an incredibly well-preserved, mostly complete linen dress.

Named the Tarkhan Dress, in 2015 it was dated to nearly 5,500 years old, making it the oldest clothing ever recovered.

Of course, the ancient Egyptians were probably not the first people to ever wear clothing.

But we haven’t found any older than the Tarkhan Dress.

So how can we figure out when we first started wearing clothes?

Well, it turns out that some of our best evidence for clothing in the past comes from a pretty unlikely - and kind of gross - place.

Now, we know that people in the past wore clothing, probably for some of the same reasons why you’re wearing clothing right now.

I hope!

Or not.

You do you.

Clothing protects us from the elements, allows us to “fit in” to societal and cultural norms, lets us cover up parts of us that we’d rather keep private, and allows us to express ourselves and our identities.

So we know it probably existed in the past, too - but where is it?

The problem is that ancient clothing is just too fragile to survive in the archaeological record, and even textiles - pieces of fabric or cloth - can be quite rare to find.

The bits and pieces that do survive are often  preserved because they end  up in extreme environmental conditions - like the dry conditions of the tomb where the Tarkhan Dress was found.

So it takes very specific circumstances for textiles to survive long enough to be discovered by archaeologists.

But we do have some surviving pieces of cloth that are even older than the Tarkhan Dress.

For example, excavations of burials at the 9,000-year-old site of Çatalhöyük in Turkey in 1964 and 2008 recovered fragmented pieces of woven textiles.

While they were originally identified as wool in 1964, later analysis in the 1980’s and 2000’s determined that they were more likely made from plant fibers, specifically flax.

And re-analysis of the fibers in 2017 concluded that they were actually made from bast fibers, which are harvested from tree bark.

This gives us an even earlier date for the use of clothing - approximately 8,500 years ago, about 3,000 years before the Tarkhan Dress.

But that’s as far as we can take evidence for clothing, right?

To small fragments of woven textiles?

Well, not necessarily.

We often think of a piece of clothing as a singular thing that exists – like a shirt on a hanger in a store that we can go try on and buy.

But we can also think of that shirt as the end product of a series of processes, including steps like turning fibers into fabric, and cutting and sewing that fabric together.

And while some of these steps might seem invisible in the archaeological record, they aren’t always.

Within Dzudzuana Cave in the country of Georgia,  archaeologists discovered  hundreds of flax fiber fragments.

Some were spun and at least one has several  knots, suggesting those fibers  were being prepared for use.

Several also seemed to be dyed; black, gray, turquoise, and even one pink fiber was found.

It’s been proposed that these fibers were  part of a local industry that produced  colorful textiles and clothing.

And here’s the kicker - these fibers dated to approximately 30,000 years ago, more than triple the age of the earliest evidence for clothing.

But that isn’t even our oldest evidence.

As we move backwards through time, the probability of surviving fibers and other fragile, organic materials gets more unlikely.

So scientists have had to get creative about what they are looking for.

If you’ve ever made a piece of clothing,  you know that, along with fabric,  it takes specialized tools.

That means finding these kinds of objects can be considered indirect evidence for clothing.

After all, what’s the point of a needle without it?

And deep in the Sibudu Cave in  South Africa, archaeologists  have uncovered an assemblage of various types of bone tools.

Among them was a fragmented needle with a point so thin that archaeologists interpret it as being used to delicately pierce through animal hide.

If this is correct, then the Sibudu Cave needle is perhaps one of the oldest pieces of evidence for clothing use at approximately 61,000 years old.

And that’s about as far back as the idea of clothing as the endpoint of a process can take us, from completed garment to textiles to fibers to tools.

But it’s not our earliest evidence, because the point of making clothing is wearing it.

And once we put a garment on, we’ve created  a new ecosystem for the things  that live on our bodies.

And it’s an unwelcome resident of that ecosystem that tells us that Homo sapiens were wearing clothing of some kind before 61,000 years ago.

Because our earliest evidence of clothing for Homo sapiens may in fact be from, lice.

See, there’s two subspecies of human lice: the human head louse and the human body louse.

And as you might be able to tell, each subspecies exists in and feeds on a different part of the body: the head louse, of course, survives and feeds on the human scalp, while the body louse feeds on the body.

But the body louse doesn’t actually live on the body, it lives on human clothing.

And scientists can trace back when these two subspecies diverged from one another.

They determined that this split would likely have happened when clothing was being used more frequently by ancient humans, because it created an ecological niche for the body louse.

So, by sequencing segments of DNA from both head and body lice, we may have gotten an answer to when that started to happen.

It seems like body lice originated at least  by 83,000 years ago and maybe  as much as 170,000 years ago!

So, is that it?

Is that the earliest date for clothing?

Well, probably not.

Remember, the body lice research only really  gives us an answer for the  origin of body lice themselves.

It’s possible that it took time after the  adoption of clothing before  lice moved into that niche.

Also, this evidence only gives us an idea about when Homo sapiens began wearing clothing - what about our close  relatives, the Neanderthals?

We know they lived in Europe during the most recent ice age – which means that they had to deal with winter temperatures somehow.

And whether or not Neanderthals wore clothes has been debated, with one of the hypotheses for their eventual demise being that they  ultimately didn’t adapt to  clothing like Homo sapiens.

But there is some evidence that suggests this isn’t entirely the case - or at the very least, that Neanderthals did wear some clothing.

For example, stone scrapers have often been  proposed as evidence for  early Neanderthal clothing.

These stone scrapers were likely used to scrape soft tissues off animal hide, which was then used as a sort of clothing - likely something draped, similar to a cape.

And a recent survey of animal bones found at Neanderthal sites has even suggested which species would be used to make clothing: wolves, foxes, and hares - all animals that would've been useful in making warm clothing.

Similar species were found at early human sites as well, suggesting that both Homo sapiens and Neanderthals used these mammals to create clothing for colder weather.

But these animals were found more frequently at Homo sapiens sites, which may point to a difference in how often clothing was created and used between both groups.

It may be that these mammals were used more often by early humans than by Neanderthals to add fur lining to clothing, giving them an extra advantage in cold weather.

There’s obviously still a lot we don’t know about Neanderthal clothing and just how old clothing actually is, but it’s possible that the evidence exists, and is just waiting to be rediscovered in a museum collection.

And researchers are always coming up with  new ways to extract data  from old finds and old sites.

And hey, if we’re able to learn about ancient clothing from body lice, who knows where our next line of evidence will come from?