Rory McLeod

At the large site of Ushdida 1, where we have this single dramatic catastrophic mass death event, you see quite a lot of shared graves in particular.

Yes.

So what was kind of extraordinary was that we found that really plague seems to have been the cause of death for everybody here.

And the reason why we didn't expect this result at all is because this flies against the expectations in our understanding of disease epidemiology for really devastating impacts of disease outbreaks upon communities.

Yes.

So we are well aware of plague strains having occurred in late Neolithic Europe until around about 5,200, 5,300 years ago, or the oldest examples from Europe.

There's one individual that states between 5,300 and 5,000 years ago.

But this is the first instance that we have of really prehistoric plague from outside of Europe, and it's also by far the oldest.

And what's kind of really exciting about these outbreaks are that they show definitively that these plague strains were deadly.

Yeah, so marmots have kind of long been guessed to be potentially the natural reservoir of plague.

And marmots are the kind of primary risk animal for plague today.

If you're in Central Asia, you see lots of news reports, unfortunately, of horse herders, for instance, eating a marmot that's undercooked, for instance, and unfortunately, then becoming infected and dying of plague.

And would it just be repeated infection, or do you think that this was human-to-human transmission?

So we think that the evidence that we have is more consistent with human-to-human transmission.

We see multiple instances of the same strains of plague turning up at contemporaneous cemetery sites quite far apart.

So the first outbreak really concentrates on these two cemetery sites of Ustida and Shumalicha.

And those are 37 kilometres apart along the River Angora.

But we see some distant biological relationships on the level of cousins or slightly more than cousins between the individuals there.

But given that they're at such different cemetery sites, we interpret archaeologically that these are different groups of people, but people that would very, very likely have come in contact at different times.

Yes, this is really, really different.