Episode Transcript
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(00:14):
Welcome to Base by Base, the paper cast that brings genomics
to you, wherever you are. Today, we're diving deep into
ancient Egypt. You know, one of history's most
well, iconic and enduring civilizations.
Absolutely legendary. But we're not just looking at
the pyramids or trying to decipher hieroglyphs today.
We're asking something maybe more fundamental.
(00:34):
How connected were these huge ancient civilizations, really?
Right. Did people mostly stay put
within their borders? Or were they moving around,
mixing, shaping history in ways where maybe only just starting
to glimpse through genetics? Exactly.
For thousands of years, ancient Egypt thrived.
We all know the images. Incredible architecture,
Sophisticated culture. And for a long time, the, let's
(00:57):
say, prevailing idea was that its people were largely local,
you know, not much genetic inputfrom outside.
But here's the snack getting ancient DNA out of Egypt.
It's been incredibly difficult. Yeah, the conditions, the heat,
the humidity, they're just terrible for preserving DNA.
So despite all the archaeology, there's been this huge gap in
understanding the genetics of the earliest Egyptians.
(01:19):
A frustrating gap. But what if?
What if just one discovery, one person preserved in a really
unique way could change everything?
A genetic key? Almost, yeah.
What if their DNA revealed connections far beyond what we'd
assumed? Connections that could reshape
how we see one of history's greatest civilizations.
(01:40):
Well, that's pretty much exactlywhat we're talking about today.
A genuinely groundbreaking finding.
Let's get into. It OK, First off, we really need
to give a shout out to the researchers here.
This was a major international effort.
Absolutely. Today we celebrate the fantastic
work of a dedicated team, including lead authors Adeline
Morris Jacobs, Jolie Irish, Ponteskoglund, Linus Goodland,
(02:02):
Flink and their many colleagues.They're from institutions like
Liverpool, John Moore's University, the Francis Crick
Institute, Cardiff University, areally strong collaboration.
And what they've done is truly advance our understanding of
ancient Egyptian population history.
How they managed to sequence thevery first whole genome from an
Old Kingdom Egyptian individual.The first whole genome.
(02:24):
That's huge for this time period.
It really is, just to give everyone a bit of context, the
dynastic period in Egypt, we're talking roughly 3150 to 30 BCE
millennia history. Pyramids, Pharaohs, incredible
stability. Exactly.
And the Old Kingdom, specifically 2686 to 2125 BCE.
(02:46):
That's the era of the First StepPyramid, the Great Pyramid of
Giza. Foundational stuff.
OK. So the traditional view, as you
said, was mostly local origins, pretty isolated genetics.
That was the thinking for a longtime, but you know, archaeology
has been dropping hints for a while.
Like what? Well, evidence of extensive
trade networks across the Fertile Crescent going way back
(03:06):
6th Millennium BCE even. Well, that early.
Yeah, and these weren't just casual contacts.
They brought big innovations to Egypt, domesticated animals,
plants, maybe even writing systems from Mesopotamia, from
the Sumerians and. Things like the pottery wheel
too, right? That wasn't necessarily invented
in Egypt. Precisely so.
Lots of cultural exchange was evident, but the genetics, That
(03:27):
was the missing piece. Because getting DNA was so hard.
Extremely hard previous attempts.
They sometimes got fragments, maybe some mitochondrial DNA or
partial nuclear DNA, but usuallyfrom much, much later periods.
We're talking thousands of yearsafter the Old Kingdom.
So the genetics of those early pyramid builders remained a
mystery. Largely, yes.
(03:49):
And that's the gap this study aimed to fill.
So how did they succeed where others struggled?
What was different this time? It really comes down to the
sample. They focused on an adult male
who is excavated at a site called Newer Rat.
And crucially, radiocarbon dating placed him right between
2855 and 2570 BCE, that slap bang in the transition from the
(04:10):
Early Dynastic to the Old Kingdom period.
Perfect timing, but what about the preservation?
That's the key. This individual wasn't just
buried in the ground. He was placed inside a large
ceramic pot which is then put inside a rock cut tomb.
Inside a pot like sealed. Seems like it created a kind of
microenvironment, protected the remains and crucially the DNA
from the worst of the degradation.
(04:32):
Like a little time capsule. Incredible.
So that unique burial was the breakthrough.
It seems very likely it allowed them to do something
unprecedented for this period, sequence a whole genome.
Not just fragments, the whole thing.
AT2X coverage, which means they read each position about twice,
giving decent confidence. A first for Old Kingdom Egypt.
How did they actually get the DNA out and sequence it?
(04:55):
They used some clever lab techniques, extracting DNA from
the cementum of teeth. That's a layer that often
preserves DNA better than bone. And they prepared special single
stranded DNA libraries which canbe better for damaged DNA than
sequenced using standard aluminatechnology.
But how do they know it's genuinely ancient DNA, not
(05:15):
modern contamination? That's always a risk, right?
It's absolutely critical question.
They performed rigorous authentication checks.
Like what? Looking for characteristic
damage patterns? Ancient DNA has specific
chemical changes, like cytosine bases turning into thymine,
especially at the ends of fragments.
They found those patterns, plus they estimated contamination
levels for modern humans, both in the nuclear and mitochondrial
(05:38):
DNA, and found them to be very low.
So they're confident this is thereal deal.
OK, so the DNA was good, but they looked at more than just
the genetics, didn't they? Oh yeah, it was a really
holistic approach. We mentioned the radiocarbon
dating, then osteology, studyingthe bones.
What did the bones tell them? He was male, about 157 to 160cm
tall, so not particularly tall for the time.
(06:00):
He lived to a pretty good age, maybe 44 to 64 years old.
That's quite old for that period.
It is, and interestingly, despite the burial suggesting
some status, his skeleton showedsigns of hard physical work.
Osteoarthritis, things like that.
So maybe a Craftsman, a Potter perhaps, given the pot burial.
It's possible it paints a picture doesn't it?
(06:21):
They also did isotope analysis on his teeth.
What does that show? It gives clues about diet and
where someone grew up. His isotopes indicated he grew
up right there in the Nile Valley's hot, dry climate.
OK. So he was local in that sense.
In terms of where he spent his childhood, yes.
And his diet was pretty typical Egyptian fare.
Omnivorous wheat, barley, some animal protein, maybe even Nile
(06:45):
fish. Fascinating detail.
OK, so back to the main event, the genetics.
What tools did they use to analyze his ancestry?
They used a standard toolkit forpopulation genetics, things like
principal component analysis or PCA, which helps visualize
genetic relationships between populations.
Also, admixture analysis, which models an individual's genome as
(07:07):
a mix of different ancestral components, and QP Adam, another
method for testing and quantifying ancestry proportions
from different source populations.
So standard tools, but applied to this unique ancient Egyptian
genome. What did they find?
What's the big reveal about his ancestry?
This is where it gets really interesting.
The analysis showed his ancestrywasn't simple at all.
It was a mix. A mix.
(07:28):
OK, the majority about 77.6% clusters closest to North
African Neolithic populations. Specifically, it looks quite
similar to genomes they've recovered from a Middle
Neolithic site in Morocco. OK.
So that fits with the idea of local North African roots
continuing from earlier periods.Exactly.
It suggests significant continuity within North Africa
(07:49):
into Egypt. That part wasn't totally
unexpected, maybe, but. There's a but isn't there?
There's a big but the remaining 22.4% roughly couldn't be
explained by North African ancestry alone.
So where did it come from? The models point strongly
towards the Eastern Fertile Crescent.
We're talking Mesopotamia, the Levant, Anatolia region.
Wow. Over a fifth of his ancestry
(08:12):
from that Far East during the Old Kingdom.
Yes, genetically similar to ancestry found in places like
Anatolia and the Levant during the Neolithic and Bronze Age.
And crucially, no single source population could explain his
genome. It was definitively a mix.
That's quite something. So it wasn't just pods and ideas
traveling, but people too. Significant numbers of people,
(08:34):
it sounds like. That's what this genetic
evidence directly implies. It suggests that the connections
between Egypt and the eastern Fertile Crescent involved actual
human migration, contributing genetically to the early
Egyptian population. It really turns that isolated
Egypt idea on its head for the Old Kingdom.
It certainly challenges it very directly.
People were moving, bringing their genes along with cultural
(08:55):
innovations. Did the study look beyond this
one individual? Did they compare him to later
Egyptians? Yes, they did.
They compared his genome to previously published data from
later periods in Egypt and also to modern Egyptians.
What does that show? Any shifts over time?
Definitely by the 3rd Intermediate Period, so maybe
705 hundred BCE, there's a noticeable increase in ancestry
(09:20):
related to the Bronze Age Levant.
In some models it goes up to nearly 65%.
A huge jump. What could explain that?
Well, it might be linked to known historical events, things
like the proposed Canaanite expansion during the Bronze Age,
or maybe the period of Hyksos rule in Egypt who came from the
Levant. It suggests more waves of
interaction and migration. So the genetic story of Egypt
(09:40):
wasn't even after the Old Kingdom.
And what about today? How do modern Egyptians fit in?
Modern Egyptian genetics are, asyou might expect, even more
complex, a real mosaic made-up of ancestry related to groups
like the New Era Individual and those Neolithic Moroccans.
That makes up a chunk, maybe 30 to 75%.
Then there's the Bronze Age Levant component, maybe 12 to
(10:01):
57%, but also significant contributions for more recent
migrations. sub-Saharan Africa features prominently.
Ancestry related to East Africans, like the ancient
Ethiopian Moto genome, makes up perhaps 7 to 56%.
Well, that's a huge range. It varies and also W African
related ancestry maybe 5 to 52%.It shows a long history of
(10:22):
connections and movements acrossthe continent and beyond,
shaping the population we see today.
A truly dynamic genetic history.So, stepping back, what are the
big implications of this study? Well, first it proves it can be
done. We can get ancient whole genomes
from early dynastic Egypt. If the preservation conditions
are right. That pot burial might be a clue
for finding more samples. Yet opens the door that seemed
(10:44):
pretty firmly shut. Absolutely.
Second, as we've discussed, it seriously challenges the idea of
early Egypt being genetically isolated.
It provides strong evidence for human migration alongside the
spread of things like farming the Neolithic package.
So people moving brought those changes, at least in part.
It looks that way. The new Iraq genome is a
concrete piece of evidence supporting older ideas based on
(11:05):
skeletal and dental shapes that hinted at links to both North
Africa and West Asia. It connects those dots.
It does, and comparing him to later Egyptians highlights this
continuous interplay between local continuity and new
migrations over millennia. It wasn't one or the other, it
was both. Of course, we have to remember
this is still just one genome, right?
(11:26):
Crucial limitation. Yes, this one individual from
New Iraq might not represent everyone in the Old Kingdom
across all of Egypt. We can't over generalize.
So what's needed next? More genomes, many more from
different places in Egypt, different time periods,
different social contexts. If possible, that's the only way
(11:46):
to build a truly detailed picture.
This. Is a fantastic start, but really
just the beginning of rewriting that genetic history.
Exactly. It's a hugely important
baseline, a proof of concept. So if we had to boil it down,
what's the key take home messagehere?
I'd say it's this. The first whole genome from Old
Kingdom Egypt reveals A surprisingly complex ancestry.
(12:07):
It shows the foundational population wasn't isolated but
was a mixture of local North African heritage and a
significant, previously hidden genetic link to the distant
eastern Fertile Crescent. A hidden connection brought to
light. Precisely.
And that really makes you think,doesn't it?
What does this discovery, the more connected view of the
ancient world, mean for how we understand the spread of
(12:28):
cultures, technologies, maybe even ideas?
How do these ancient groups really interact to build the
civilizations we study? It opens up so many new
questions, a really exciting time for the field.
Definitely something to ponder. This episode was based on an
Open Access article under the CCBY 4 Point O license.
You can find a direct link to the paper and the license in our
(12:48):
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