June 5, 2024 • 11 mins
When you think of fossils, you probably imagine dinosaurs. But did you know that soft body parts, like the brain, can become fossils too?
In this episode, forensic anthropologist Alexandra Morton-Hayward explores the science of brain fossilisation. Skeletons have been found in wells, Incan temples, salt mines and many other unusual locations, often with no other organs, hair or skin preserved. With only a brain nested in the skull, we are asking … how can this happen?
Listen now to find out and discover how this research is unravelling ancient human history!
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
>> Emily Elias (00:06):
If you show me a picture of a fossil,
I think I know what I'm looking at
and how it's made. But cards on the table, I have no idea,
let alone how something soft and squishy
like a brain would turn into one. But we're gonna
get the answers on this episode of the Oxford
Sparks big Questions podcast. We're asking,
(00:26):
how do you fossilise a brain?
Hello, I'm Emily Elias, and this is the
show where we seek out the brightest minds at the University of Oxford,
and we ask them the big questions.
And for this one, we have found a
researcher who is really good at finding
fossilised brains and taking very good care of
(00:48):
them.
>> Ally Morton Haywood (00:48):
My name is Ally Morton Haywood, and, I'm a forensic
anthropologist at the University of Oxford.
>> Emily Elias (00:53):
Okay, so, forensic anthropologists, so you
know how fossils are made, because
as much as I want to say, like, I'm smart and I know this,
I don't really know this, absolutely.
>> Ally Morton Haywood (01:05):
It's not a straightforward question. how does a fossil
get made? When we think of fossils, first and
foremost, we're thinking of the preserved remains of
the fossil organisms, so the ancient deceased
plants or animals themselves that are preserved in the rock.
And this is what we call a body fossil. But, of course,
there are other types of fossils, too, like
(01:25):
moulds and cars. So, for example, the victims of the
Vesuvius eruption who are trapped in ash.
And then there are also trace fossils as well, the remains
of footprints and burrows and other traces of
ancient life. But the most common method of
fossilisation that we tend to think of is this way in
which we make body fossils, and that's called
permineralization.
>> Emily Elias (01:45):
So what's that like? Is like, a mommy fossil and a
daddy fossil love each other very much, and they decide they're gonna
make a baby fossil.
>> Ally Morton Haywood (01:55):
You could think of it that way. the way I would explain it is
when an organism is buried in sediments like
sand or mud, the spaces within the remains which
are left behind by decayed soft tissue, for
example, they become filled with these mineral
rich fluids that move through porous sediments.
And eventually these minerals can entirely replace the
organic material, and their remains are literally turned
(02:17):
into stone or petrified. Petra is the
latin word for rock, or stone. And, this process
can occur in really small spaces, even
within a cell wall. And so this can produce these
incredibly detailed, beautiful fossils
that are made from the mommy and the daddy.
>> Emily Elias (02:34):
So can anything that is, like a soft
tissue turn into a fossil?
Cause I know you specialise in brains. Are
there better soft tissues that
fossilise than others.
>> Ally Morton Haywood (02:48):
Absolutely. So, permineralization that we just
talked about relies on the soft tissue decaying.
But this doesn't always happen. If your body
fossil is not per minimalized, turned into rock, not
compressed, turned into carbon, and it's not a mould
or a cast, then it's possible you have what we would
broadly term organic preservation. And here we're
(03:08):
talking about preservation of the soft tissues, which we'd
otherwise expect to decay quickly. So
organic preservation can take all sorts of different
forms, and it's much more poorly understood than
per mineralization, for example. On the one
hand, you can have the straightforward preservation of whole
organisms in amber, which is simply a matter of
(03:28):
forming this oxygen free environment that
halts decomposition. But what I'm really
interested in is when you have the kind of more m mysterious
preservation of an organism's
constituent biomolecules, like proteins,
lipids and DNA. This can be different
depending on the organ that's involved. As
you mentioned, I study brains, and
(03:50):
brains forensically. We know that this is one of the first
organs to decompose post mortem. It's
super weird to find it preserved in the archaeological and fossil
records, and we don't really understand what is
happening in the brain. for example, if you have a
waterlogged environment with a clay or iron
component in the soil, you are likely to
(04:10):
find a skeleton with no other soft tissue.
No skin, no hair, no liver, no
pancreas, no lungs, nothing else, but just the
brain rattling around in the skull. And that
suggests that there is a mechanism of
preservation that is unique to the brain and doesn't
occur in other organs. And so the purpose
of my research is to try and figure out what that
(04:32):
mechanism is.
>> Emily Elias (04:33):
okay, so, ally, like, where are these, like, brains actually found? Are
they like, hanging out in somebody's fridge in like, a jar?
Or are they like, a palaeontologist is digging and
then they come upon it in, like,
in the field?
>> Ally Morton Haywood (04:47):
Yeah, absolutely. Great question. So I think I may be the
only person in the world that has them in a jar.
I study them day in and day out, and there are
hundreds in my fridge here in Oxford. These brains are
found in all sorts of different burial environments.
So they could be at the bottom of a well.
We, have 80 something prisoners from, like, 18th century
(05:07):
France that were found at the bottom of a well. We also
find a lot in churchyards and other kind
of conventional cemetery burial sites.
We find them on the top of volcanoes, like
incan sacrifice. They're ancient
mummies that conventionally, the ancient Egyptians
practised acceribration, which is the removal of the
brain. In some situations, they didn't do a great job.
(05:30):
And now we have them in our fridge. So there are all sorts of
different places, but they're always found
where the individual was buried. So it's not like
someone has dug them up and then preserved them
or it was removed prior to burial, for
example, these are all spontaneously preserved
in the ground, and they really, truly can be
(05:50):
super ancient. So palaeontologists have found
the preserved nervous systems of critters
like ammonites and trilobites, which is those
things that are swimming about in the sea, if you think of an
ancient sea. So these things are half a billion
years old. So all over the world,
as part of the research that I'm doing, I've been
reaching out to individuals in museums
(06:13):
and research institutions who have been
excavating these brains, and I'm collecting
them together here at Oxford so that we can begin to answer
these questions about how they're preserving when all
other organs are perishing.
>> Emily Elias (06:26):
Wait, okay, so, like, you have, how many brains do
you have in Oxford?
>> Ally Morton Haywood (06:31):
So we have, more than 570.
No. Excuse me? We have more than 600. I
collected 30 last week from Belgium.
So we now have more than 600 here in the fridges at
Oxford. They are in all sorts of
ranges of preservation, so some are absolutely
gorgeous. They look like a kind of a shrunken
walnut in the palm of your hand. They're all shrunken
(06:53):
to around a fifth of their natural
size in life. And so they actually fit quite
neatly in the fridges, in all sorts of different
containers. Some sites have just
dozens and dozens of brains coming out of the ground, and
they don't know exactly how to store them or where to put them. So
they've been using things like chinese takeaway
containers or jam jars. And so they're
(07:16):
just crammed into our fridges, ready for
study.
>> Emily Elias (07:19):
Oh, my God. So you have, like, a brain library of
fossils?
>> Ally Morton Haywood (07:23):
Absolutely. And I love. I know it's a bit crazy,
but I used to work as an undertaker, so I'm very
familiar working with the dead. And just as
I did when I was undertaking, I would talk to the deceased
around me, kind of as a coping mechanism for myself, because
it can be a little creepy when you're working around the dead. So
whenever I open the fridges, I. I chat to them and make sure
(07:43):
that they're comfortable and behaving themselves.
>> Emily Elias (07:47):
Do you have any wayward, brains that are acting
up or are they all chill?
>> Ally Morton Haywood (07:51):
I have one that, is my favourite. he
comes on the road with me if I ever go to talks
or, if I go to give a lecture somewhere else, or if
I'm talking to kids about fossilisation. I call
him Rusty because he's this incredible bright
orange red colour. And, so Rusty is like,
he's my go to. He's my dude.
>> Emily Elias (08:11):
Rip rusty. Thank you for your service.
>> Ally Morton Haywood (08:15):
He is like a guide dog for explaining how brains
can preserve. And there's nothing like seeing
that in the palm of someone's hand. You know,
it's really hard to grasp, but these things, they
look exactly like brains. If you think of an
MRI in an episode of House or some other medical
tv show, they look exactly like that, but they're
bright orange or black,
(08:37):
they're speckled with yellow.
so there's a lot of iron in these things. But other than that and
the fact that they're smaller than you'd expect, they look
exactly like brains.
>> Emily Elias (08:47):
So how do you go about then, like, actually analysing them
to do all your research with?
>> Ally Morton Haywood (08:52):
We have this huge archive that's currently
untapped of ancient human brains. More than
4400 excavated since the
mid 16 hundreds, but less than 1% have
been investigated at the molecular level. So there is
huge scope for exploration. One of the
first things that I did in exploring these tissues is I
(09:12):
tried to image them using, MRI. So
magnetic resonance imaging. And again, if you
think about a medical show where they're looking into the brain, they're
probably using mris. It's this incredible way
to really zoom into a tissue and, look at
the white matter pathways that tell us about
whether someone is left or right handed or what their
(09:32):
childhood was. Like. This incredibly
detailed information that you can get from an
MRI, but not
if you've essentially soaked a brain in iron for the
last 300 years, because
it's a magnet. Right? So I just
essentially put a really rusty brain. And it was
rusty, actually. And I felt so small when the
(09:54):
technician said to me, you've just handed me a magnet to
put inside a giant magnet. It was a
complete disaster. We got no information. But fortunately,
we've really thought through the approach that we're using
since, so we're studying the iron itself and doing
other kind of imaging techniques as well. But, yeah, MRI
was not the best idea.
>> Emily Elias (10:13):
In retrospect, what do you hope? What is the big
thing mystery that you want to unlock as you do
all this different brain analysis?
>> Ally Morton Haywood (10:21):
So the main question for me is how
does the brain preserve on geological time
scales, when forensically we know that it's one of
the first organs to decompose? In fact, I mentioned
that I used to be an undertaker. My experience undertaking is the
brain just liquefies super quickly. But
clearly this huge archive we've published
(10:42):
about shows that the brain actually, it preserves
relatively frequently in a range of different environments,
and said, why? Is the question
that I really want to answer. And I think once we've
answered that, we can begin to do some of the really
cool research and figure out what ancient brains
can tell us about ancient life. So that's the super
(11:02):
exciting next step.
>> Emily Elias (11:12):
This podcast was brought to you by Oxford Sparks from the
University of Oxford, with music by John Lyons and
a special thanks to ally Morton Hayward. Tell us what you think about
this podcast. We are on the Internet at oxfordsparks.
Or you can go to our website, oxfordsparks
ox aC UK.
I'm Emily Elias. Bye for now.
If you show me a picture of a fossil,
I think I know what I'm looking at
and how it's made. But cards on the table, I have no idea,
let alone how something soft and squishy
like a brain would turn into one. But we're gonna
get the answers on this episode of the Oxford
Sparks big Questions podcast. We're asking,
(00:26):
how do you fossilise a brain?
Hello, I'm Emily Elias, and this is the
show where we seek out the brightest minds at the University of Oxford,
and we ask them the big questions.
And for this one, we have found a
researcher who is really good at finding
fossilised brains and taking very good care of
(00:48):
them.
>> Ally Morton Haywood (00:48):
My name is Ally Morton Haywood, and, I'm a forensic
anthropologist at the University of Oxford.
>> Emily Elias (00:53):
Okay, so, forensic anthropologists, so you
know how fossils are made, because
as much as I want to say, like, I'm smart and I know this,
I don't really know this, absolutely.
>> Ally Morton Haywood (01:05):
It's not a straightforward question. how does a fossil
get made? When we think of fossils, first and
foremost, we're thinking of the preserved remains of
the fossil organisms, so the ancient deceased
plants or animals themselves that are preserved in the rock.
And this is what we call a body fossil. But, of course,
there are other types of fossils, too, like
(01:25):
moulds and cars. So, for example, the victims of the
Vesuvius eruption who are trapped in ash.
And then there are also trace fossils as well, the remains
of footprints and burrows and other traces of
ancient life. But the most common method of
fossilisation that we tend to think of is this way in
which we make body fossils, and that's called
permineralization.
>> Emily Elias (01:45):
So what's that like? Is like, a mommy fossil and a
daddy fossil love each other very much, and they decide they're gonna
make a baby fossil.
>> Ally Morton Haywood (01:55):
You could think of it that way. the way I would explain it is
when an organism is buried in sediments like
sand or mud, the spaces within the remains which
are left behind by decayed soft tissue, for
example, they become filled with these mineral
rich fluids that move through porous sediments.
And eventually these minerals can entirely replace the
organic material, and their remains are literally turned
(02:17):
into stone or petrified. Petra is the
latin word for rock, or stone. And, this process
can occur in really small spaces, even
within a cell wall. And so this can produce these
incredibly detailed, beautiful fossils
that are made from the mommy and the daddy.
>> Emily Elias (02:34):
So can anything that is, like a soft
tissue turn into a fossil?
Cause I know you specialise in brains. Are
there better soft tissues that
fossilise than others.
>> Ally Morton Haywood (02:48):
Absolutely. So, permineralization that we just
talked about relies on the soft tissue decaying.
But this doesn't always happen. If your body
fossil is not per minimalized, turned into rock, not
compressed, turned into carbon, and it's not a mould
or a cast, then it's possible you have what we would
broadly term organic preservation. And here we're
(03:08):
talking about preservation of the soft tissues, which we'd
otherwise expect to decay quickly. So
organic preservation can take all sorts of different
forms, and it's much more poorly understood than
per mineralization, for example. On the one
hand, you can have the straightforward preservation of whole
organisms in amber, which is simply a matter of
(03:28):
forming this oxygen free environment that
halts decomposition. But what I'm really
interested in is when you have the kind of more m mysterious
preservation of an organism's
constituent biomolecules, like proteins,
lipids and DNA. This can be different
depending on the organ that's involved. As
you mentioned, I study brains, and
(03:50):
brains forensically. We know that this is one of the first
organs to decompose post mortem. It's
super weird to find it preserved in the archaeological and fossil
records, and we don't really understand what is
happening in the brain. for example, if you have a
waterlogged environment with a clay or iron
component in the soil, you are likely to
(04:10):
find a skeleton with no other soft tissue.
No skin, no hair, no liver, no
pancreas, no lungs, nothing else, but just the
brain rattling around in the skull. And that
suggests that there is a mechanism of
preservation that is unique to the brain and doesn't
occur in other organs. And so the purpose
of my research is to try and figure out what that
(04:32):
mechanism is.
>> Emily Elias (04:33):
okay, so, ally, like, where are these, like, brains actually found? Are
they like, hanging out in somebody's fridge in like, a jar?
Or are they like, a palaeontologist is digging and
then they come upon it in, like,
in the field?
>> Ally Morton Haywood (04:47):
Yeah, absolutely. Great question. So I think I may be the
only person in the world that has them in a jar.
I study them day in and day out, and there are
hundreds in my fridge here in Oxford. These brains are
found in all sorts of different burial environments.
So they could be at the bottom of a well.
We, have 80 something prisoners from, like, 18th century
(05:07):
France that were found at the bottom of a well. We also
find a lot in churchyards and other kind
of conventional cemetery burial sites.
We find them on the top of volcanoes, like
incan sacrifice. They're ancient
mummies that conventionally, the ancient Egyptians
practised acceribration, which is the removal of the
brain. In some situations, they didn't do a great job.
(05:30):
And now we have them in our fridge. So there are all sorts of
different places, but they're always found
where the individual was buried. So it's not like
someone has dug them up and then preserved them
or it was removed prior to burial, for
example, these are all spontaneously preserved
in the ground, and they really, truly can be
(05:50):
super ancient. So palaeontologists have found
the preserved nervous systems of critters
like ammonites and trilobites, which is those
things that are swimming about in the sea, if you think of an
ancient sea. So these things are half a billion
years old. So all over the world,
as part of the research that I'm doing, I've been
reaching out to individuals in museums
(06:13):
and research institutions who have been
excavating these brains, and I'm collecting
them together here at Oxford so that we can begin to answer
these questions about how they're preserving when all
other organs are perishing.
>> Emily Elias (06:26):
Wait, okay, so, like, you have, how many brains do
you have in Oxford?
>> Ally Morton Haywood (06:31):
So we have, more than 570.
No. Excuse me? We have more than 600. I
collected 30 last week from Belgium.
So we now have more than 600 here in the fridges at
Oxford. They are in all sorts of
ranges of preservation, so some are absolutely
gorgeous. They look like a kind of a shrunken
walnut in the palm of your hand. They're all shrunken
(06:53):
to around a fifth of their natural
size in life. And so they actually fit quite
neatly in the fridges, in all sorts of different
containers. Some sites have just
dozens and dozens of brains coming out of the ground, and
they don't know exactly how to store them or where to put them. So
they've been using things like chinese takeaway
containers or jam jars. And so they're
(07:16):
just crammed into our fridges, ready for
study.
>> Emily Elias (07:19):
Oh, my God. So you have, like, a brain library of
fossils?
>> Ally Morton Haywood (07:23):
Absolutely. And I love. I know it's a bit crazy,
but I used to work as an undertaker, so I'm very
familiar working with the dead. And just as
I did when I was undertaking, I would talk to the deceased
around me, kind of as a coping mechanism for myself, because
it can be a little creepy when you're working around the dead. So
whenever I open the fridges, I. I chat to them and make sure
(07:43):
that they're comfortable and behaving themselves.
>> Emily Elias (07:47):
Do you have any wayward, brains that are acting
up or are they all chill?
>> Ally Morton Haywood (07:51):
I have one that, is my favourite. he
comes on the road with me if I ever go to talks
or, if I go to give a lecture somewhere else, or if
I'm talking to kids about fossilisation. I call
him Rusty because he's this incredible bright
orange red colour. And, so Rusty is like,
he's my go to. He's my dude.
>> Emily Elias (08:11):
Rip rusty. Thank you for your service.
>> Ally Morton Haywood (08:15):
He is like a guide dog for explaining how brains
can preserve. And there's nothing like seeing
that in the palm of someone's hand. You know,
it's really hard to grasp, but these things, they
look exactly like brains. If you think of an
MRI in an episode of House or some other medical
tv show, they look exactly like that, but they're
bright orange or black,
(08:37):
they're speckled with yellow.
so there's a lot of iron in these things. But other than that and
the fact that they're smaller than you'd expect, they look
exactly like brains.
>> Emily Elias (08:47):
So how do you go about then, like, actually analysing them
to do all your research with?
>> Ally Morton Haywood (08:52):
We have this huge archive that's currently
untapped of ancient human brains. More than
4400 excavated since the
mid 16 hundreds, but less than 1% have
been investigated at the molecular level. So there is
huge scope for exploration. One of the
first things that I did in exploring these tissues is I
(09:12):
tried to image them using, MRI. So
magnetic resonance imaging. And again, if you
think about a medical show where they're looking into the brain, they're
probably using mris. It's this incredible way
to really zoom into a tissue and, look at
the white matter pathways that tell us about
whether someone is left or right handed or what their
(09:32):
childhood was. Like. This incredibly
detailed information that you can get from an
MRI, but not
if you've essentially soaked a brain in iron for the
last 300 years, because
it's a magnet. Right? So I just
essentially put a really rusty brain. And it was
rusty, actually. And I felt so small when the
(09:54):
technician said to me, you've just handed me a magnet to
put inside a giant magnet. It was a
complete disaster. We got no information. But fortunately,
we've really thought through the approach that we're using
since, so we're studying the iron itself and doing
other kind of imaging techniques as well. But, yeah, MRI
was not the best idea.
>> Emily Elias (10:13):
In retrospect, what do you hope? What is the big
thing mystery that you want to unlock as you do
all this different brain analysis?
>> Ally Morton Haywood (10:21):
So the main question for me is how
does the brain preserve on geological time
scales, when forensically we know that it's one of
the first organs to decompose? In fact, I mentioned
that I used to be an undertaker. My experience undertaking is the
brain just liquefies super quickly. But
clearly this huge archive we've published
(10:42):
about shows that the brain actually, it preserves
relatively frequently in a range of different environments,
and said, why? Is the question
that I really want to answer. And I think once we've
answered that, we can begin to do some of the really
cool research and figure out what ancient brains
can tell us about ancient life. So that's the super
(11:02):
exciting next step.
>> Emily Elias (11:12):
This podcast was brought to you by Oxford Sparks from the
University of Oxford, with music by John Lyons and
a special thanks to ally Morton Hayward. Tell us what you think about
this podcast. We are on the Internet at oxfordsparks.
Or you can go to our website, oxfordsparks
ox aC UK.
I'm Emily Elias. Bye for now.
Popular Podcasts
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com
24/7 News: The Latest
The latest news in 4 minutes updated every hour, every day.
Therapy Gecko
An unlicensed lizard psychologist travels the universe talking to strangers about absolutely nothing. TO CALL THE GECKO: follow me on https://www.twitch.tv/lyleforever to get a notification for when I am taking calls. I am usually live Mondays, Wednesdays, and Fridays but lately a lot of other times too. I am a gecko.