Death of Sediba
This section focuses on the life and death of two members of the early hominin species, Australopithecus sediba, who roamed the Earth some 1.98 Million Years Ago.
Sediba was distantly related to modern humans, and has so far only been found at the site of Malapa, in the Cradle of Humankind.
Sediba was distantly related to modern humans, and has so far only been found at the site of Malapa, in the Cradle of Humankind.
Malapa is the first fossil site to have provided evidence of the manner of death of an australopithecine, other than death caused by predators or natural causes. It is also the earliest site to provide evidence of a BONE TUMOUR in the hominin fossil record.
Who were these hominins?
Karabo (MH1) was a boy who died around 12 years of age; in the last few years of his life he was affected by a tumour which grew into his spine. MH2 was a female who died in adulthood. Using forensic analyses of bone damage to their skeletons we can determine that they died following a fatal fall into the cave.
This is the story of their life and death...
Today the Malapa site is (quite literally) a hole in the ground. Almost 2 Million Years Ago the cave and its landscape were quite different.
Malapa today is the base of a deep cave system within the dolomitic limestone of the Cradle of Humankind. Geology tells us that the cave entrance would originally have been some 20 to 30 metres above the present land surface – over the last 2 million years the landscape has eroded away to leave just the base of the cave system and it is within this base that the bodies of MH1 and MH2 were found. The remains of other animals were also found within the cave, including carnivores, zebra, antelopes and buck, baboon and tortoise.
How did the hominins and other animals get into the cave? And why couldn’t they get out?
To answer this we use the science of FORENSIC TAPHONOMY. This is the study of processes which affect bodies at or around the time of death, and is usually used by FORENSIC ANTHROPOLOGISTS to help identify dead bodies and investigate medico-legal cases such as homicide, suicide or mass fatality. At Malapa these forensic skills have been applied to understand how MH1 and MH2 may have died.
The team of forensic anthropologists from South Africa and the United States studied the pattern and types of breaks (fractures) which occurred across both skeletons.
Who were these hominins?
Karabo (MH1) was a boy who died around 12 years of age; in the last few years of his life he was affected by a tumour which grew into his spine. MH2 was a female who died in adulthood. Using forensic analyses of bone damage to their skeletons we can determine that they died following a fatal fall into the cave.
This is the story of their life and death...
Today the Malapa site is (quite literally) a hole in the ground. Almost 2 Million Years Ago the cave and its landscape were quite different.
Malapa today is the base of a deep cave system within the dolomitic limestone of the Cradle of Humankind. Geology tells us that the cave entrance would originally have been some 20 to 30 metres above the present land surface – over the last 2 million years the landscape has eroded away to leave just the base of the cave system and it is within this base that the bodies of MH1 and MH2 were found. The remains of other animals were also found within the cave, including carnivores, zebra, antelopes and buck, baboon and tortoise.
How did the hominins and other animals get into the cave? And why couldn’t they get out?
To answer this we use the science of FORENSIC TAPHONOMY. This is the study of processes which affect bodies at or around the time of death, and is usually used by FORENSIC ANTHROPOLOGISTS to help identify dead bodies and investigate medico-legal cases such as homicide, suicide or mass fatality. At Malapa these forensic skills have been applied to understand how MH1 and MH2 may have died.
The team of forensic anthropologists from South Africa and the United States studied the pattern and types of breaks (fractures) which occurred across both skeletons.
Most of these breaks happened after MH1 and MH2 were dead (we call this post-mortem – after death), but some of the breaks occurred peri-mortem (around the time of death). Peri-mortem fractures can be used to reconstruct a series of physical actions which happened around the time of death of the hominins.
MH1 (Karabo) received a significant blow to the face, which fractured part of his mandible (lower jaw) and broke his teeth in his lower and upper jaws.
MH1 (Karabo) received a significant blow to the face, which fractured part of his mandible (lower jaw) and broke his teeth in his lower and upper jaws.
MH2 has more damage. She displays fractures of the right arm, with a break running through the elbow joint and the wrist, and the first and second ribs.
The pattern of injuries in both hominins is consistent with damage resulting from a fall from a height, with similar patterns seen in modern forensic cases.
When we combine the results of forensic analyses with the study of the geology and cave sediments, we think that the hominins and other animals most likely fell into a cave opening some 5 to 10 metres below the ancient ground surface; in falling MH1 and MH2 broke bones and were unable to climb back out (as were other animals). The fall may not have killed them, but we know that there is no sign of healing of the breaks, indicating they died either in, or shortly after the fall.
When we combine the results of forensic analyses with the study of the geology and cave sediments, we think that the hominins and other animals most likely fell into a cave opening some 5 to 10 metres below the ancient ground surface; in falling MH1 and MH2 broke bones and were unable to climb back out (as were other animals). The fall may not have killed them, but we know that there is no sign of healing of the breaks, indicating they died either in, or shortly after the fall.
After death, their bodies may have been naturally mummified. Eventually their bodies were carried deeper down into the cave system by a flow of mud and water, before finally coming to rest. There they fossilised, and were eventually exposed some 1.98 Million Years after their deaths.
How do we know that the breakage of MH1 and MH2’s bones occurred this way? And how do we know they happened around the time of death? To answer those questions, we apply FORENSIC TRAUMA ANALYSIS – this is usually used to understand violent death in forensic cases such as gunshot wounds, beatings, stabbings and explosions.
FORENSIC TRAUMA ANALYSIS uses the principles of BONE BIOMECHANICS to understand what happens when bone breaks – we call this FAILURE.
How do we know that the breakage of MH1 and MH2’s bones occurred this way? And how do we know they happened around the time of death? To answer those questions, we apply FORENSIC TRAUMA ANALYSIS – this is usually used to understand violent death in forensic cases such as gunshot wounds, beatings, stabbings and explosions.
FORENSIC TRAUMA ANALYSIS uses the principles of BONE BIOMECHANICS to understand what happens when bone breaks – we call this FAILURE.
How do bones break?
Bone fails (breaks) when the amount of energy (force) being applied to the bone is greater than the bones ability to resist. Forces which operate on bone include COMPRESSION, TENSION, BENDING, TORSION AND SHEARING forces. Bone is very good at resisting (not breaking) under compression, but less effective at resisting other types of force. When energy is applied to a long bone (such as in a fall) the bone may be subject to bending. The bone is bent along its long axis, causing compression on one side and tension to build up on the opposing side. If this bending force is slight (a short fall), then the bone returns to its normal shape when the force is removed. |
What is Bone? |
However, if the amount of force is greater than the bone can withstand (reaches its FAILURE POINT) then where tension has built up, the structure of the bone is literally pulled apart. This causes a fracture to form, which propagates out from the point of failure into the bone.
Only bone which is ‘green’ – either alive or still wet following death – reacts this way, and this allows us to tell whether a fracture occurred around the time of death or afterwards when the bone has begun to decompose and dry out.
Peri versus post-mortem
After death bone begins to decompose along with other parts of a body, though this takes longer than other structures such as skin, organs or blood. When bone decomposes the collagen within the bone degrades, changing the biomechanical properties of the bone.
Bone which is green (fresh) fractures very differently to bone which is dry as a result of the relative difference between the inorganic and organic components –bone becomes progressively more brittle as it decomposes (loses collagen) and dries out.
As a result, dry bone fractures tend to be across the axis of the bone or occur in blocks (DISPLAY), whereas green fractures produce oblique or curved breaks which reflect the basic mechanical competency of living bone.
We have used these principles to determine whether the trauma suffered by MH1 and MH2 occurred around or sometime after death. The type of fractures, their pattern and location, are consistent with those seen in fatal falls in recent forensic cases.
Forensic taphonomy has allowed us to determine that MH1 and MH2 sustained significant injuries to their skeletons, most likely as a result of falling through an opening leading into the Malapa Cave system – such openings are often referred to as DEATH TRAPS.
We also now know that Karabo (MH1) was unwell at the time of his death – in fact his skeleton preserves the earliest evidence for neoplastic disease (a BONE TUMOUR or NEW GROWTH) – so far found in the hominin fossil record.
There is some evidence that tumours are ancient, with the earliest case dating from a fossil fish from 300 million years ago. Tumours (benign) and cancers (malignant) have also been found in Jurassic dinosaurs and European mammoths dating from 24,000 years ago.
Until recently the earliest clear evidence in the human lineage dated to 120,000 years ago, with a case of FIBROUS DYSPLASIA in a rib from one of the Krapina Neanderthals. In the modern world tumours and cancers are all-too common, and cancer is now one of the most common causes of death in Western societies.
When the skeleton of Karabo was studied, a small lesion (defect or hole) was seen in one of his thoracic vertebrae.
Only bone which is ‘green’ – either alive or still wet following death – reacts this way, and this allows us to tell whether a fracture occurred around the time of death or afterwards when the bone has begun to decompose and dry out.
Peri versus post-mortem
After death bone begins to decompose along with other parts of a body, though this takes longer than other structures such as skin, organs or blood. When bone decomposes the collagen within the bone degrades, changing the biomechanical properties of the bone.
Bone which is green (fresh) fractures very differently to bone which is dry as a result of the relative difference between the inorganic and organic components –bone becomes progressively more brittle as it decomposes (loses collagen) and dries out.
As a result, dry bone fractures tend to be across the axis of the bone or occur in blocks (DISPLAY), whereas green fractures produce oblique or curved breaks which reflect the basic mechanical competency of living bone.
We have used these principles to determine whether the trauma suffered by MH1 and MH2 occurred around or sometime after death. The type of fractures, their pattern and location, are consistent with those seen in fatal falls in recent forensic cases.
Forensic taphonomy has allowed us to determine that MH1 and MH2 sustained significant injuries to their skeletons, most likely as a result of falling through an opening leading into the Malapa Cave system – such openings are often referred to as DEATH TRAPS.
We also now know that Karabo (MH1) was unwell at the time of his death – in fact his skeleton preserves the earliest evidence for neoplastic disease (a BONE TUMOUR or NEW GROWTH) – so far found in the hominin fossil record.
There is some evidence that tumours are ancient, with the earliest case dating from a fossil fish from 300 million years ago. Tumours (benign) and cancers (malignant) have also been found in Jurassic dinosaurs and European mammoths dating from 24,000 years ago.
Until recently the earliest clear evidence in the human lineage dated to 120,000 years ago, with a case of FIBROUS DYSPLASIA in a rib from one of the Krapina Neanderthals. In the modern world tumours and cancers are all-too common, and cancer is now one of the most common causes of death in Western societies.
When the skeleton of Karabo was studied, a small lesion (defect or hole) was seen in one of his thoracic vertebrae.
This was studied using high-energy x-rays using a process called PHASE-CONTRAST X-RAY SYNCHROTRON MICROTOMOGRAPHY.
When we looked inside the lesion we saw that the edges facing towards his back (DORSAL or POSTERIOR) displayed evidence of bone-healing (we use the term SCLEROSIS, a slow-forming bony process) indicating that the disease took a long time to develop. When we look at the front part of the lesion (VENTRAL or ANTERIOR) we see evidence of LYSIS or an active destruction process, where the bone is being eaten away. A rendered negative surface model of the lesion demonstrates this clearly.
In studying the shape of the lesion, how active it was, what part of the body was affected, and Karabo’s age and sex, we can narrow down the diagnosis of the disease. In this case we came up with a diagnosis of BENIGN OSTEOID OSTEOMA.
How did this affect Karabo?
Even though the neoplasm was benign (it would not have been fatal), the position of the tumour may have affected muscle function and movement of both his shoulder blade and his upper back because of the close association between the affected region and overlaying or closely inserting muscles – this may have limited his range of movement, and perhaps reduced his ability to climb.
What is the disease found at Malapa?
Tumors of any kind are rare in archaeological populations and are all but unknown in the hominin record, highlighting the importance of this discovery. The presence at Malapa predates other evidence for neoplasm in hominins by some 1.86 million years; the recognition of this neoplasm may be highly influenced by the taphonomic and geological environment of the site, which allowed such a condition to be preserved.
How did this affect Karabo?
Even though the neoplasm was benign (it would not have been fatal), the position of the tumour may have affected muscle function and movement of both his shoulder blade and his upper back because of the close association between the affected region and overlaying or closely inserting muscles – this may have limited his range of movement, and perhaps reduced his ability to climb.
What is the disease found at Malapa?
Tumors of any kind are rare in archaeological populations and are all but unknown in the hominin record, highlighting the importance of this discovery. The presence at Malapa predates other evidence for neoplasm in hominins by some 1.86 million years; the recognition of this neoplasm may be highly influenced by the taphonomic and geological environment of the site, which allowed such a condition to be preserved.