New Scientist - USA (2022-06-04)

8 | New Scientist | 4 June 2022

MOUNT Vesuvius in southern

Italy erupted in AD 79 to

devastating effect, destroying

several Roman settlements,

including Herculaneum to the

west of the volcano and Pompeii

to the south-east. Analysis of

human remains found buried

under the ash and pumice that

blanketed these ancient towns

is revealing new details about the

people who died in the eruption.

The eruption killed many of

Pompeii’s inhabitants, but it

didn’t destroy their DNA. The first

complete genome from Pompeii

has now been sequenced and it

reveals genetic markers that

haven’t been seen before in

ancient Roman DNA.

The volcanic ash and debris

that covered Pompeii is estimated

to have been at least 250°C – hot

enough to kill people instantly

and, presumably, cause significant

damage to their internal tissues

as well as their DNA.

“There was the expectation

that the high temperatures

would make our effort in DNA

sequencing in Pompeii fruitless,”

says Gabriele Scorrano at the

University of Copenhagen,

Denmark. “Cremated bodies,

for example, show no sign of

DNA preservation, according

to multiple studies.”

But Scorrano and his colleagues

decided to look for ancient DNA

anyway. They focused on the

skeletal remains of two people

discovered in a building called the

Casa del Fabbro, or House of the

Craftsman. The pair – a man in his

30s and a woman who was at least

50 years old – seem to have been

lying on a low couch in what may

have been a dining room at the

moment they died (pictured).

The researchers managed to

obtain genetic material from both

skeletons, although only the man’s

bones yielded enough DNA to

piece together a full genome.

Scorrano and his colleagues

then compared the man’s genome

with those from 1030 ancient

people who lived during the past

5000 years or so and 471 present-

day people from western Eurasia.

This revealed that the man who

died in Pompeii had comparable

DNA to that recovered from the

skeletons of people living in Italy

at the height of the Roman Empire.

However, the team did find

differences. In particular,

groups of genes on the man’s

Y chromosome and in his

mitochondrial DNA were unlike

those seen in earlier studies of

ancient Romans. Instead, they

were similar to sequences carried

by some people living today on

the Italian island of Sardinia.

Hints of bacterial DNA in the

bone sample collected from the

man in Pompeii are consistent

with existing evidence from

his skeleton that he had spinal

tuberculosis (Scientific Reports,

doi.org/hwkz).

“This pathology causes

severe pain, such as lumbago

and sciatica,” says Scorrano.

This might explain why he didn’t

flee when the eruption began,

as many Pompeiians did.

It is only because of

improvements in analytical

techniques that we can now

extract DNA from the skeletons

preserved at Pompeii, says Pier

Paolo Petrone at the University of

Naples Federico II in Italy. He says

the work shows there are “always

new discoveries” to be made even

at world-famous sites.

Petrone and his colleagues

have also studied human bones

recovered from Pompeii, as well

as Herculaneum, where ash is

thought to have been particularly

hot. Estimates suggest it baked

the town at temperatures of

500°C and killed some residents

instantly, before vaporising

their flesh.

He and his team extracted

small samples of bone from seven

human skeletons recovered from

Pompeii and five recovered from

Herculaneum. They found that

they could isolate traces of ancient

protein from all of the samples.

“This is the first work aimed

at the detection of [proteins]

in people exposed to high

temperatures,” says Petrone.

Surprisingly, he says, bones

from Herculaneum contained

a greater diversity of proteins

than those from Pompeii, even

though they experienced higher

temperatures (Scientific Reports,

doi.org/hwpv).

This may be because the bones

at the two sites have encountered

different environmental

conditions since the disaster.

The volcanic ash at Herculaneum

is thought to have remained

waterlogged for most of the

past 2000 years, which might

have limited the breakdown of

proteins in the bones by microbes.

Fluctuations in the local water

table mean the ash at Pompeii

periodically dried out, says

Petrone, probably allowing

for more microbial-driven

decomposition.

The fact that the proteins in

human bone can survive high

temperatures could inspire

further investigation, the team

says. For instance, it may lead to

research exploring which of the

1000 or so proteins generally

found in human bone degrade at

particular temperatures. Forensic

investigators could use this to

estimate a fire’s temperature

based on human remains. ❚

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First genome of Pompeii resident

Human remains from towns destroyed by the eruption of Mount Vesuvius reveal the

genetics of ancient Romans and the resilience of bone proteins, reports Colin Barras

The two individuals

found in the Casa del

Fabbro in Pompeii

News

250 ̊C

Estimated temperature of volcanic

ash that buried Pompeii

500 ̊C

Estimated temperature of volcanic

ash that buried Herculaneum