The process of creating our model of a Neanderthal

As visitors wander among the gallery's fossils, tools, and other artifacts, two standout characters put a human face to the final stage of our epic evolutionary journey.

Looking into the twinkling eyes in the weathered features of the Neanderthal man, one can feel a moment of recognition, of recognising another fellow human (albeit of a different species).

He is based on Homo neanderthalensis remains discovered at Spy in Belgium 40,000 years ago.

Our Belgian Neanderthal stands 155cm tall and is in his twenties.

The other gentleman in the gallery is a model of an early modern human living around 30,000 years ago, known as a Cro-Magnon by some scientists, who was part of Europe's Gravettian prehistoric culture.

He is made up of a male Homo sapiens skeleton from Paviland in Wales (the famous 'Red Lady' who wasn't a lady) and a roughly contemporaneous skull from Pedmost in the Czech Republic.

Identical twins Adrie and Alfons Kennis, who are among the world's leading prehistoric model makers, collaborated with Museum scientists for six months to create the two ancient human replicas. The models, which were specially commissioned, combine scientific and aesthetic interpretation.

'The scientists bring the knowledge, and we make the characters,' Adrie Kennis says. '

Prof Chris Stringer, the Museum's human evolution expert, was delighted to contribute to the creation of the reconstruction.

'The models are based on the best scientific evidence we could find.'

'When they come face to face with the Neanderthal and Cro-Magnon men, people have as close to a real encounter as they can get,' he says, adding that 'their faces are really alive.' '

The models aid in highlighting key distinctions between Neanderthals and an early example of our own species. Both are naked in order to display their physiques.

The early modern human in the Human Evolution gallery at the Museum stands 175cm tall and is in his fifties.

Early modern humans were taller and less stocky than Neanderthals, suggesting that they were better suited to endurance running rather than short bursts of speed.

The body proportions of the Homo sapiens man were similar to those of men living in hot climates today.

The Neanderthal body, on the other hand, was adapted to cold environments. Despite this, he would have worn animal skins to survive in the cold climate of the last glaciation.

People sometimes mistake the modern human for having a cigarette in his mouth, but tobacco and smoking are, as far as we know, a much more recent concept. The item in question is a twig paintbrush.

The man is posed as if he is in the process of decorating his body. His upper legs are covered in large black designs, and his fingers are stained with the manganese dioxide pigment he used to make them.

The markings are genuine early modern human designs, copied from engravings discovered on mammoth bone at Pedmost.

The legs of an early modern human have realistic body art.

His lower legs are ochre-colored. The remains upon which this model is based were discovered in 1823, smeared with this naturally occurring iron oxide pigment and buried with periwinkle shells and ivory rods and rings.

The Neanderthal is also depicted with body decoration, indicating that this artistic behavior was not limited to modern humans. In fact, body painting may have been the first form of art - ochre was used in Africa and Europe at least 200,000 years ago.

Evidence suggests that Neanderthals used pigment to decorate or camouflage their bodies as long as 60,000 years ago.

Manganese dioxide blocks with clear signs of use, including some shaped into crayons, have been discovered in at least 70 Neanderthal sites. They used charcoal similarly and appeared to prefer black to red or yellow.

The Kennis brothers wanted to pose the humans naturally, as if you were going to meet them.

'How a person stands says a lot about him,' says Alfons. 'We show him doing casual things, not in a hunting pose with a spear.' '

'We didn't want to make a clichéd ape-man,' Adrie adds. '

So, what goes into the creation of such models?

'What we do is palaeoart,' Alfons explains. 'We reconstruct extinct mammals, particularly early humans.'

'When human relics are discovered, people want to know what the individual would have looked like, so we use forensic methods to reconstruct them.' '

Before they were painted, the early modern human and Neanderthal model heads sat on a shelf alongside a skull cast in the Kennis brothers' studio.

These methods include layering clay over a skull cast and fleshing out the face with a chart that details known tissue thicknesses at specific points.

'The difference between most forensic cases and ours is that ours are very, very, very old cases,' Alfons adds. '

The brothers must also construct the replica skeleton, straightening out any twisted bones before layering on the artificial muscles.

This is used to create a silicone mold in which to create the models.

The Kennis brothers take a model out of its mold.

'Once you put all the muscles on, it becomes very realistic,' Alfons says. 'But it's not yet a real character.' '

An element of chance

Creating believable characters and imbuing faces with emotion both necessitate artistic ability.

'These aren't portraits,' Alfons clarifies. 'It's a general idea of how someone might have appeared.' '

One of the Kennis brothers combines colors for a model.

Put your hand on your face and see what happens. Can you feel your bone where it is very close to the skin?

When you know the shape of the skull, it's easy to predict how people will look around the part of the face where the flesh is thin, according to Alfons. As an example, consider the bridge of the nose or the area of the forehead known as the frontal bone.

'But what gives a person a lot of character is the fullness of the lips, the shape of the nostrils, the shape of the tip of the nose, the folds of the eyes - and you can't know this,' Alfons clarifies. '

The completed models arrived at the Museum in early 2014 and were displayed in a temporary exhibition about humans in the United Kingdom. They were then incorporated into the Human Evolution gallery at the Museum, which opened in December 2015.

The Kennis brothers recently reconstructed the face of another modern human, Cheddar Man - Britain's oldest nearly complete Homo sapiens skeleton.

This ground-breaking reconstruction was created using cutting-edge sequencing technology by a team of scientists from the Museum and University College London.

The Museum provided 3D scans of Cheddar Man's skull in addition to genetic evidence of his skin tone, eye color, and hair type. These were made with high-tech equipment designed for use on the International Space Station.

The scans allowed the brothers to 3D print Cheddar Man's skull, allowing them to flesh out his facial features and incorporate the results of his genetic profile.

Cheddar Man's facial reconstruction in front of his skeleton Both are on display in the Human Evolution gallery at the Museum.