Colonising Mars

Today is the installation day for a new exhibition in the Anatomical Museum at Edinburgh University looking at Colonising Mars. Our team looked at anatomical changes.

Here is our piece – Life on Mars with David.

Let me start by acknowledging that David was carved as a white man and we are meant to be decolonising everything but we went with David – despite the known issues about proportions and it being carved so that it looked correct when viewed from below – because it was easier to show a colour change and we had a pop culture reference to address.

Also acknowledging the words of the evolutionary anatomist we consulted that ‘trying to predict evolution changes is an exercise in futility’ – view the piece as a conversation starter.

Also – selection pressure isn’t really a thing anymore as we do not allow the weakest in society to die (quite rightly). It is no longer an evolutionary advantage to have certain physical traits.

All that been said – What did we change?

Height – The gravity on Mars is 38% of that on Earth. It is the resistance to gravity that gives our bones their strength. Bones lose up to 5% of their mineral density per month of space flight. The reduced gravity would lead to more fragile bones and hence increase the likelihood of fractures. We thought we would address this by developing a stockier frame to protect against fractures.

Head size – as bone fractures are more likely we thought that birth would be more likely to proceed by C section. There is a debate that it is the passing through the birth canal that limits the size of the human head. With this restriction gone, head size could increase. (Mitteroecker, P. et al (2016) cliff edge model of obstetric selection in humans  PNAS,113(51))

Eye size – the light on Mars is the equivalent to a cloudy day on Earth. The adaptions that the eyes might make would probably all be internal but that doesn’t work on a model, so we made the eyes bigger.

Skin – the annual exposure to radiation is greater on Mars – 30 millisieverts as opposed to 3. For some reason all of the people discussing colonising mars have increased the pigmentation in the skin with carotenoids rather than melanin. We couldn’t find out why but increased the orange colour to fit in with the prediction that skin pigmentation would increase.

Spleen – we developed a bulge on the left to indicate a larger spleen. We based this on research on the Bajau people who spend a lot of their time free diving. These people have larger spleens. Upon exposure to an oxygen restricted environment- part of the divers response, the spleen pushes a large volume of red blood cells into the circulation so that the breath can be held for longer. We thought there would inevitably be some sort of breach of the containment on Mars and so the ability to hold the breath for a longer time might be helpful and might actually be a genuine evolutionary selection criteria. (Trenkman,M. (2018) A breath holding adaptation. Nature Review Genetics 19.)

Limb circumference – some of our body shape is due to the distribution of fluids within our tissues. This is affected by gravity and so a reduced gravity would redistribute our fluids. According to NASA the circumference of the leg can reduce by 30% during space flight ( We wanted to reflect this effect and so reduced limb circumference and removed the chiseled abs.

We hope it starts a conversation and maybe makes people aware of what parts of their bodies’ do and why they are like they are.

Thoughts on Post Mortem Live

This is a long post with only the one picture for reasons that will become apparent

This weekend I attended the Post-Mortem live event.  It was a hard decision, but it is talked about a lot in my research and some people who have never seen it have views about it.  In the same stretched logic that led me to read the infamous 50 shades of grey before voicing an opinion, I thought I should go and see it.

(It should be noted that I was not neutral about the event before seeing it.  I am an anatomist.  I did my training in the dissection rooms of UK medical schools.  I am not a pathologist.  I have never attended a post-mortem and my experience in that area is confined to Dame Prof Sue Black’s books, Carla Valentine documentaries and TV.  I am not an entomologist, I have not studied forensics and I have not conducted mass spec or gas chromatography.  I very much doubt any one person has.)

The event was 4 hours long, although the doors did not open until it was meant to start, and it had a 35 minute break so it was closer to 3 hours.

I help run the anatomy night events where we run dissections which are usually just over an hour.  In that time the anatomists cover one organ.  We are currently submitting a manuscript on the educational value of those events. 

This event covered crime scene analysis – 2 separate potential crime scenes, collection of swabs, kidney dissection, soil analysis, DNA analysis including the explanation of exons, introns and small tandem repeats, soil analysis, entomological study of fly larvae to estimate time of death, viewing the body under UV light to identify sperm samples, craniotomy and removal of the brain, dissection of the larynx, bronchi and lungs, and heart.

To be fair, in the one page programme which the majority of the audience did not appear to have – it cost extra, there were QR codes to all of these techniques and a paragraph that said that the show depicted something that was very far from the normal post mortem process but this had been driven by feedback from2021 where guests said they wanted more grit and forensics and to find out what happened.

The issue with this event is the pretend use of human remains.  In this case a body sitting at the front of the stage that had supposedly been dead for around 16 days.  You might think – who would be fooled by a synthetic model, but the vast majority of the population have not seen a dead body – they have no comparator and when the remains are there with pig intestines added to the abdomen you could see some people thinking this was real.

In the queue outside, the person behind me talked about the fact that he was a registered body donor. ‘This could be me in a few year’s time – still it’s the learning that is important.’  He said he was surprised the event wasn’t taking place in a hospital or a university. He did approach the presenter during one of the activates and I did overhear them say that it was not a real body as that would be illegal, but no room wide announcement was given. The potential donor standing a few feet from the model had to be told it wasn’t real. I can’t see anything in the programme that explains the origins of the body.

There were a number of people in the room who were there for the same reason as me.  There were several students who were there because this was their only access to dissection.  There were some people there who were thinking of going into forensics (this misrepresentation of the role of a single forensics person feeds the forensics frenzy), some thinking of going into medicine and a bunch who were just interested. The audience covered a wide age range but was probably more towards the 20-30 year age group.  There were a total of 112 people with tickets costing around £50-£80.

The presenter had spent 5 years studying anatomy and had worked at the Royal College of Surgeons. (I had previously tried to find out the qualifications of the staff at these events and was told by the company that it could not be disclosed because of data protection). Their anatomy was only challenged by the limits of the show.  They cut the cranium off with a scalpel, they mentioned a bone saw but obviously didn’t use it.  They removed the cranium and the model brain literally fell out – it wasn’t connected to anything.  When it came to the digestive tract – which was stained blue due to an attempted poisoning, they had to explain the lack of an appendix – why on earth they didn’t just say the victim had had an appendectomy I don’t know – I guess saying the same thing twice a day for several months was wearing a bit thin, but they suggested that the appendix often just falls off or explodes.

Except for the two points above, there didn’t appear to be anything wrong with the anatomy.  I can’t comment on the fly larvae each group had to go up and collect from the corpse to work out the timeline and sticking a pH metre into the soil sample to differentiate between the two crime scenes was a time filler.  Even having qualifications in medical microbiology and anatomy I found the speed at which they went from ‘this is a kidney’ to loops of henle, to mass spectrometry to DNA profiles startling and some of the slides of the power point were flashed up so quickly it was impossible to read then.  The room was dimly lit with spot lights at the front facing the audience which made it hard to see although they had no issues with people crowding around their pretend human remains and taking pictures. They had a camera operator who zoomed in on certain thing that were projected on to two big screens.

Each table had a bucket and a tray and got to dissect a kidney, identify fake larvae, open by a larynx, trachea and lungs and a heart as well as take the pH of a soil sample.  Several swabs were taken and sent off to a lab with results coming back during the event. Dissection instructions were given verbally, and we were provided with scissors. The one presenter toured the room to check that people were getting on OK.  The trachea had had a black substance (possibly charcoal solution) placed in it to suggest particulate matter that had been breathed in.

If the event has been called who killed Miss Piggy then I would not have any problems with it.  It would have been quite entertaining although maybe not as marketable. The event could even have run without the pretend rotting corpse at the front of the room.  I would have liked a big sign up telling everyone that they were dissecting pigs remains.  Some of the audience even commented on the amount of pig remains that were being used and speculated that they were probably been thrown away afterwards – maybe they were going back to dog food – I don’t know.

I left fairly unimpressed.  Unimpressed with human kind in general that we find the idea of paying to look at dead bodies acceptable, and unimpressed that there are business people out there prepared to exploit it.  The programme claims that the company supplies over 40 UK universities and a dozen NHS trusts although this applies to the ITAE event management and production company, maybe not the post mortem section of the company. Disappointed that there are body donors out there who think this is what might happen to their bodies and also slightly worried that it didn’t actually seem to concern them.

Next month I am booked into the Living Autopsy.  An event being run by Dr Suzy Lishman CBE as part of the 60th anniversary of the Royal College of Pathologists.  It will be interesting to see the difference.

Depictions of Anatomy

You can’t get around depictions of Anatomy – as soon as you draw anything you have depicted anatomy and unless you are adopt a painting style that is some what abstract, you open yourself up to claims that your depiction isn’t accurate.

A recent literature review uncovered several publications where modern anatomists were pointing out the errors of famous artists – a future blog post maybe.

Last week I was out for dinner at the Edinburgh restaurant 21212. It had been on our list of restaurants to visit for some time. The food was fantastic, and the presentation was outstanding.

Each table had a small figure on it. The table beside ours had this little model of a dragon.

I had spent some of the previous week finishing an article for the British Fantasy Society about winged mythical beasts and the problems they present for anatomy.

You can see that this dragon has wings and shoulders which poses questions as to how either limb works without effecting the other. There is always something around to make start a conversation on anatomy – this is a good one as most people don’t fully understand the relationship between their arm and their shoulder blade and when you add breathing in to that equation they rarely appreciate the fact that they are all connected.

Upstairs, in the private dining room, there is an amazing picture

This is a small part of the painting by Caravaggio called the 7 acts of mercy. The seven acts are actually all depicted in the lower part of the painting and this section just shows two angels looking down on a scene that we can no longer see.

What we can see though are pairs of wings coming out of the back of the angels. How would that work? An excellent backdrop for a science talk about anatomy of flight – somehow I can’t see the science fair budget running to a private dining experience.

Still more to discover

In 2016 I wrote a book on William Burke, the provider of bodies for medical teaching in 1828. I am based in Edinburgh where tales of Burke and Hare are everywhere and tourists have easy access to various versions of the truth.

That was the main driver to get the research done and get as close to the real story out there for people to read.

Since 2016 I have been speaking at various events, turning up on TV screens and been in receipt of various documents that continue the story of Burke and Hare.

Late in 2021 I discovered that the cell that held Burke after his conviction was still in existence. Its not open to the public but it is preserved under the courts in Edinburgh.

I was lucky enough to go down there – it is tiny. We know that Burke complained that he couldn’t see the sky from his cell because of the height of the buildings behind the court. The window is 75 inches from the floor, so quite high up anyway and if the sky couldn’t be seen then there wouldn’t be a lot of light getting in there. The door is solid metal with a tiny peep hole. The cell would have been in almost complete darkness. The room itself is 63 inches by 61 inches. We know from the skeleton that Burke was 5 foot four so it would have been impossible for him to lay down in the cell apart from on the diagonal and you have to assume there would have been some sort of furniture in there if even just a cot and some straw. Obviously prisoner comfort was not a priority in those days but I’d like you to take a moment to compare it with the cells other people were held in – pictured below and now full of cabinets.

Burke’s Cell
Other cells

When I asked why there was such a difference, my guide suggested that they just didn’t like what Burke had been up to and they were just being mean. He lived in that cell for 1 month.

The court where the case was heard is also still around, now a library for advocates. The second picture shows the windows of the court room from the cowgate. Not quite sure how a crowd gathered under these windows to hear the court case – I may need to go back and look at plans to understand if there were more windows.

The court where the trial took place

‘Tis the Season

It’s that time of year again. The time when things that should not fly take to the air. Obviously in this context it is reindeer that we are talking about but it fits in quite nicely with an article I am working on for the British Fantasy Society about other things where it is hard to explain flight.

Once you start digging into flight you realise that there are some pretty grey areas. We can explain lift in terms of a fixed wing but when we start looking at the constantly moving wings of flying creatures its gets more complicated. If we then take in the modifications that bats can make to their wing membrane it gets even more complicated. In an adaptation that was portrayed in the batman movies, but probably missed by most, bats can vary the rigidity of their wing membranes by contracting and relaxing little fibres that cover the wing surface. This can provide a rigid wing for the down stroke but a pliable membrane that can be folded for the upstroke to reduce drag.

However, let’s concentrate on something a little more festive – bird flight.

Bird’s have made a number of modifications that allow them to fly that may have escaped your notice until you start thinking about how other creatures might be able to take to the air.

Have you ever noticed how birds do not have big muscles on their backs? Muscles can only move things by contracting – they pull their two ends together. Your biceps cause your arm to bend up bringing your hand towards your shoulder but the muscles that move the bone in the opposite direction are on the opposite side of your arm. When this muscle, the tricep, contracts it straightens the arm.

Have you ever noticed that birds do not have big muscles on their backs? If you look at the shoulders of a bat they have bulky shoulders. They look a bit like a mouse who has been to the gym, but not birds.

Why don’t birds have big muscles on their backs to pull the wings back up? They have developed two very clever adaptations.

The first one is this – a wishbone or furcula. You can imagine this to be two fused collar bones. As the arms of wings come down the two ends of the bone are pulled apart. As soon as the tension is removed the bone springs back into place and pulls the wings back up. This reduces the requirement to have large muscles to pull the wings back up but doesn’t remove it completely.

Birds do have a muscle that pulls the wings back up – its called the supracoracoideus and if you have ever prepared a bird in the kitchen you have probably seen it and not appreciated what is does.

As you prepare a chicken breast you will have noticed the small fillet of meat that lies under the larger breast. This isn’t usual in anatomy. As humans we have a large pectoralis muscle and a smaller one under it and both work to bring the upper limb forwards, but that is not the case in birds

As you can see in the image. The smaller muscles found under the pectoralis major in birds is actually the supracoracoideus muscle and it actually pulls the wings back up even though it is situated on the front on the chest. It does this via a clever little looping system at the shoulder joint where it wraps around the top of the coracoid bone.

This allows birds to move their wings up and down with no big bulky muscles on the back of the bird to impinge the range of motion of the wing. It’s clever.

It does, however, mess things up if you wants a mythical creature to fly and not have a very muscular chest or to have functioning arms as well as wings.

Still, for now we can just let the angels descend to the shephards and not worry too much about how they did it.

Merry Christmas

Education or Entertainment?

With the return to campus, it is now possible to have conversations with colleagues who you bump into during the course of the day.

I had one such interaction last week. I was greeted with the exclamation,

‘Oh, I have a question for you!  Which Anatomy Act brought in the ability to donate your body?’

Bit of a strange opener but I confirmed it was the first act in 1832.  

You had actually always been able to donate your body if you wanted to but after the Anatomy Act came in in 1832, Jeremy Bentham famously left his body to anatomists and an auto icon was created which is still on display in London.

Second question, how long is a body left embalming before it is dissected?

 At this point I thought this was a bit strange.  I was fairly sure this person knew the answer to this so I took a punt.

‘Did you watch silent witness this week?’

What followed was a 20 minute conversation about all the things that we didn’t thing had been portrayed quite accurately in the television series. This included the rather alarming fact that a donor body had been dissected when the family had objected.

Which brings me back to the title.  Are these programs to educate or entertain?

I know a couple of people who have had short careers in forensics.  They went into the role not realising that there is a lot of sticking to the rules, ensuring everything is done the same, every single time.  They maybe thought they were going to undertake post mortems, do all the lab analysis, interview witnesses and even track down killers, all the things we see a single character doing in many tv series.  That is what makes the program entertaining.

Is there an onus to make sure our entertainment is educational or at least not factually incorrect?

I have been watching the Dexter box sets. The picture on the right here was described as a clean cut between the tarsal bones.

I think we all know it is nothing of the sort. If you want more examples you only have to google Dexter anatomical mistakes to be shown a selection of poorly described injuries.

Does it matter – does it detract from the entertainment of the show? I’m not sure it does, but we need to be sure that people are not accepting fictional TV shows as a source of knowledge.

I have not watched any of Gray’s Anatomy but I have been advised never to watch it in the company of anyone medically qualified. A google search for their mistakes produces a long list.

I’m maybe showing my age but I did watch Top Gun with two RAF pilots. I am assured that apparently the missiles fire as soon as they lock on to the target in that model of plane.

I remember them correcting the error in that film decades later. Maybe we should be looking at these errors as opportunities to engage in a bit of SciComm and ensure that people remember the correct information rather than complaining that they should employ more qualified researchers, although if Hollywood wants an anatomical fact checker, I am open to offers.

Sent from my iPad

Felt it?

I’ve recently been experimenting with the anatomy felts.

Having produced a spinal cord section, I wondered if that could be miniaturised such that it could be produced in a workshop. I appreciate a felting workshop to produce a miniature spinal cord section is a niche market but…why not.

The first thing is colour choice. With 6 ascending tracts and 7 descending tracts there is a lot of wool to sort out. I wanted to keep some sort of colour themes so went with purple for ascending and oranges for descending.

Just over an hour later and 1 have a section of a spinal cord safety encased in a deep frame from ikea and ready to find a home with a friendly neuroanatomist across the pond.

Now all I need to find is a bunch of neuro nerds who might want to join in the fun.

A Helping Hand

There are some great medical illustrators and artists out there who produce some fantastic works of art.

Inspired by some of Sarai Llamas work, I turned to Netter to see if it would be possible to convert some of his epic dissection illustrations into felts.

The making of the neck felt is already covered in this blog on another post.

My second project would be a hand.

I started by drawing around my hand and then felting in a base of core wool to create the bones

At this point I made the first mistake. I had drawn around my own hand and so I was felting a left hand whereas all of the illustrations were of a right hand.

The transition of deep to superficial is important in anatomy. It’s equally important in art. When painting you start with the sky and the background and then work forward. When felting you need to start with any structures that are going to be deep in the final felt.

The first thing to place was the radial artery.

This artery sits in what is called the ‘anatomical snuff box’ and disappears below the dorsal interosseous (between the bones) that lie between the finger and thumb.

Once this was in place the other interosseous muscles had to be placed. Each muscle runs from the length of the metacarpel (bones of the hand) towards the knuckle joint. The fibres of the wool were placed in the same direction to give the impression of the muscle fibres.

The final muscle by the little finger of the hand is the abductor digiti minimi muscle and its fibres run in the opposite direction, down towards the wrist.

At this point someone contacted me via twitter and enquired about purchasing it. I suggested they might want to wait until it was finished – it could all go wrong.

The next stage was to add in all of the tendons that connect the muscles of the forearm to the fingers. These were fine wires that were covered in wool and then felted into place.

Some of these tendons in the hand are connected and so these bridges between them had to felted into place before the tendons were fixed to the hand.

It is these bridges that give the hand some of its quirky properties.

If you place you hand on a table and curl your second finger under the palm, as shown in the picture, then it’s impossible to left your ring finger up from the surface. This is due to the connections that exist between the second and third finger tendons. If the model didn’t have these connections in it then it wouldn’t depict a human hand. Ive never tried the finger trick with any other mammal so I am not sure if it’s a common feature.

Once the tendons were in place it was a case of adding the coverings of the different compartments that group the tendons together as they pass underneath the extensor retinaculum.

The fingers were then covered in white fibres laying across the finger to represent the transverse fibres of the extensor expansions. Towards the finger tip the two lateral bands of the extensor tendon came together towards the insertion point at the base of the distal phalanx – visible in final picture.

The whole outline then had to have a layer of subcutaneous fat added in a pleasing shade of yellow before adding a layer of skin, choosing a tone that resembled my own skin as I had drawn around my hand at the start of the process.

The resulting hand was framed and packaged off to the scientist who first expressed an interest in it.

I shall return to Netter for more inspiration.


Last weekend saw the first National Undergraduate Neuroanatomy Competition that took place on line.

The NUNC team were absolutely on fire and produced a fantastic competition with a professionally delivered MCQ and spotter.

At the closing remarks I spotted this little felt on their desk.

It is a cross section of a spinal cord showing the ascending and descending paths along with the nerve rootlets leaving the spine and the spinal canal in the centre. I produced it a few months before the competition and had sent it down to Dr Scott Border because he is a neuro guy (and my house is getting a bit full of felts).

There is such a thing as neurophobia; the fear of learning neuroanatomy because it is so complicated. Each of the coloured sections above carries neurons either towards the brain – green, the sensory pathways, or away from the brain – red, the motor pathways. When an injury occurs to the spine someone who understands this can work out where the damage is based on the symptoms that are displayed. It’s mind blowing.

When I learnt my neuroanatomy I studied these cross sections for ages. The information went in well enough to pass the exams.

Having spent a few hours felting the various tracts, their positions and relations to each other, it is now firmly cemented in there.

The act of doing enhances the retention of the information. Maybe learning can be combined with a craft project that helps us destress. Maybe there is more of a role for art in learning. Could be an interesting little research project.

Standing on your own two feet

Art meets Anatomy

I have been experimenting with various felting techniques building towards a bigger project. Last month it was smaller faces and so I made a model of a small girl. Usually when making felt models a wire armature is used. This gives a frame to build around and enables the structure to stand easily when finished.

The other option is to make it anatomically correct.

When humans became bipedal it had an effect on the spine, causing it to become a series of gentle curves. If you image an foetus curled into a ball then all of the spine curves towards the back – this is the shape of the primary curves, described as kyphotic. The curves that can be seen at the back and the neck, where the curve is towards the front of the body are described as secondary curves or lordotic. Between them they document your development.

As a foetus you have just the one kyphotic curve. Once born you spend most of your time lying on your back. Around 3 months you develop the ability to lift your head. The head is a large weight balanced on top of a narrow support structure called the neck. To be able to balance it the neck arches forward so that the mass of the head can be centred over the support. This gives you the first secondary curve at the neck. Imagine how big your neck muscles would have to be if you didn’t have this curve and you relied on the muscles to hold your head up!

At this point you have a child who can sit up with a beautiful straight back. Despite what you might have heard in exercise classes that this is the posture you should be aiming for – it is unobtainable as a bipedal human.

The next stage of development requires you to balance the weight of your body over two small feet. This is not possible unless your body arches forward to recentralise the centre of mass of the torso. This gives you the secondary curve in your lower back. Only with these curves in place can a human body be easily balanced over two feet. Apes lack these curves and so they can only walk a short distance on two feet and it looks ungainly. Despite what people say about the drawings of Di Vinci showing a J shaped spine – they don’t – he drew bipedal people – they would have had the same curves as you and I.

To get a felt model to balance these same curves had to be in place. It’s only when you are trying to shape a small body that you appreciate how pronounced these curves can be. The bottom has to stick out quite a way and you need to make sure the shoulders are pulled back. Placing one foot in front of the other made it easier to ensure the balance was obtained.

The feet and ankle joint also had to be correct. When you look at the ankle from behind it is trapezoid shaped and behind the lower leg. This structure needs to be the same to offer a counter to the balance of the body; an ankle that sits behind the leg and a forefoot that spreads out.

Once you have all these in place, it will stand.

What has this taught me?

To balance not only do I need the curves in my back, I also need my head to be on top of my neck and my shoulders back. No more head forward posture or slouching shoulders because these are postures that are causing muscles all over my body to work more.

I balance best when my feet are flat and my forefoot spread – remember that when you are wearing shoes that alter the shape of your foot.

Only when all of those things are in alignment will I be able to balance without extra muscular effort.

It amazing what you can learn from felt.

p.s. – I managed the small face