Most people get problems with their spine, particularly as they get older, some from wear and tear and other people for many other reasons, but have you ever considered why? Well, people with lower back problems are more inclined to have a spine similar in shape to the chimpanzee, our closest ape relatives.
And there is a lesion which develops in the disc within the bones of the spine that is the reason for its differing shape, and it would have caused the vertebrae to change as humans evolved from using four legs to two legs, and now researchers say that their findings could assist doctors to predict who may be at risk of back problems.
The vertebrae of chimpanzees, orangutans and ancient human skeletons were examined to investigate the connection between the shapes of the bones of the vertebrae, perpendicular movement and the health of the human spine, and evidently, they provide helpful insights into our ancestor’s health and lifestyles.
The skeletons further provided data about how humans evolved to move on two “rear” legs, and the findings revealed that the vertebrae of humans with disc problems were familiar in appearance to those of our closest ape relatives, the chimpanzee, than are the vertebrae of humans without disc problems.
The study picked up that these individuals have a lesion described as a Schmorl’s node, a small hernia which can happen in the disc between the vertebrae, and even though there’s not one explanation for the node, it’s believed to be associated to stress and strain on the lower back.
Evolution is not perfect, so over several thousands of years humans have not all adapted in the same way, and it suggests that the pathological vertebrae of some people may be less well adapted for walking upright.
But human and chimp genes may have divided 13 million years ago, more than twice as long ago as had been generally believed, and it has further been found that male chimps pass on far more genetic mutations to their offspring than male humans do, showing earlier unknown evolutionary differentiation between the species.
Chimpanzees are the nearest living relations to humans, so studying chimps could assist scientists to learn more about human development.
The amount of genetic differentiation between two species shows how closely related the species are, and by calculating the rate at which those variations happen, researchers can then determine when the ancestors of species such as humans and chimpanzees may have diverged.
Chimpanzees usually have one more thoracic, one less lumbar vertebra, and one less caudal vertebra than do humans. Both usually have seven cervical vertebrae and usually, the combined thoracic, lumbar, and sacral regions consist of 22 vertebrae, and chimpanzees lack the acute curves of the human column, and the angle between the lumbar and sacral area is more acute.
But the actual enigma for the evolutionist is not to explain the species of organism that have actually ever existed, the actual problem is for the evolutionist is how is it that most classes of potential and apparently reasonable organisms have never existed.
The dilemma is to explain the location of the void spaces in the clustered assembly of occupied points. It’s easy to describe organisms that have never existed. There are snakes that live in grass, but there is no grass eating snakes. Birds rest on trees, yet, apart from a few exceptions, they don’t all eat the greenery around them, but rather consume a vast abundance of energy hunting for food.
But if you suffer from lower back pain, your vertebrae might closely resemble that of our nearest ape relative, the chimpanzee.
Our vertebrae have discs of cartilage between the vertebrae, which allow our spines a measure of pliancy, and further, play a significant role as shock absorbers when we move around and do anything that’s high impact. But sometimes these discs can shift, or become herniated. This means a small lesion opens up in the fibrous outer layer of the disc, and the inner viscous hub is able to move out of place, either moving horizontally or vertically, into the bone.
These lesions, further known as Schmorl’s nodes, can result in some pretty severe back pain, but how and why they occur isn’t very well understood, and it’s been suggested that the shape of someone’s vertebrae could be directly linked to their probability of developing Schmorl’s nodes.
And because humans exhibit considerably more degenerative and traumatic spinal pain than non-human primates, many research groups have hypothesised that the cause of this usually debilitating damage might be associated to the way we move around, on two feet.
And with this hypothesis in mind researchers have led a cross-species study of spine shapes, looking at medieval period human skeletons, matching them with the bones of chimpanzees and orangutans.
The aim was to examine the relationship between the shapes of the bones making up the spines of each species and their means of movement, in order to understand that disc lesions are more prone to affect people with spine shapes closely resembling those of our ape ancestors.
As humans evolved, our vertebrae slowly morphed into shapes that can better handle the pressure of walking erect, but, as researchers pointed out, our vertebral shape is almost certainly determined by multiple genes. This suggests that within the human species, some individuals can be expected to have vertebrae that are closer in appearance to those of our common ancestor than others.
It further suggests that those people are less adapted for bipedalism (using two legs for walking), and after analysing the skeletons, researchers discovered that healthy vertebrae were distinct in each species, but unhealthy vertebrae in humans, those afflicted with Schmorl’s nodes, were statistically indistinguishable from those of chimpanzees.
This suggests they more closely resembled the chimp vertebrae than the healthy human spines, and the conclusions showed that the vertebrae of humans with disc problems were closer in appearance to those of our closest ape relative, the chimpanzee, than are the vertebrae of humans without disc problems, and that the pathological vertebrae of some people are well less adapted for walking upright.
I honestly couldn’t envision us all walking about on all fours, but then I did say that it was a truly bad thing us coming out of the trees!