By: Prof. Dr. Mohammad Tariqur Rahman
Whether in forests or in captivity, animals are not free from diseases. However, generally speaking forest animals are least vulnerable to genetic disorders.
A pragmatic response to that generalization could be, “we don’t know if forest animals have fewer or more genetic disorders than humans because we don’t have enough scientific evidence to support that notion, or not many studies were aimed to investigate genetic disorders in animals.”
However, this response may not sustain as a valid argument if genetic disorders in animals of domestic breeds are put under microscope.
Genetic disorders in domestic animals are prevalent in domestic breeds raised for unique physical and functional traits. These disorders include but not limited to skin diseases with dry, itchy and inflamed skin, tumour growth and inherited anxiety in dogs; neurological abnormalities in Jaguar carpet pythons; abnormal growth and formation of bones (also known as osteodystrophy) in satin guinea pigs; and “fainting” goats.
For more information see the Canine Inherited Disorders Database – a joint initiative of the Sir James Dunn Animal Welfare Centre at the Atlantic Veterinary College, University of Prince Edward Island, and the Canadian Veterinary Medical Association.
Simply put, those genetic disorders are not prevalent in their natural counterparts having natural, i.e., unaltered genetic composition. Hence genetic breeds showing higher prevalence of genetic defects could be deeply rooted in selective and targeted genetic modification that is designed for a desired physical or functional trait.
Compared to natural animals, humans seem to be vulnerable to many genetic defects. Humans suffer from an array of genetic disorders causing unusual physical traits such as abnormal arrangement of teeth or even fatal diseases such as cancer.
For humans, there is no selective breeding with any targeted physical or functional traits. Hence, we can’t blame any possible “targeted” genetic modification that could be blamed for the genetic disorders they suffer from. At the same time, it is well established that one or another form of genetic alteration, i.e., mutation is responsible for genetic disorders in humans.
Apparently, there is nothing special about this preceding discussion to conform genetic mutation or targeted genetic modification as a cause of genetic disorders in humans and domestic animal breeds. It may on the other hand sound ridiculous, to relate human genetic disorders in relation to domestic animal breeds.
This however, may not sound ridiculous if we start digging into the absence or rare occurrence of genetic disorders in forest animals.
In their natural habitat, animals maintain their natural way of life. They eat what they are supposed to eat. They do what they are supposed to do. They seem not to stress themselves unless they face hitherto unseen challenges. In other words, animals maintain a consistent “animal lifestyle” – be it either for their natural instinct or lack of intelligence.
Contrary to animals, humans as intelligent beings change their lifestyle in as many ways as possible. Our explorative instincts make (read: force) us in a never ending dynamic and challenging episodes in life.
Needless to say, we have changed our lifestyle in many ways compared to how our earlier generations had their lifestyle. By discarding natural foods, we become heavily dependent on processed foods with preservatives, we are imposed with an imbalance of work-related stress, we live a life with least possible physical labour and highest possible exposure to radiation, we live in pigeon holes – an inevitable adobe in urban livings – devoid of natural touch during our day to day living; and last but not least we ignore natural familial bonding.
All in all, our sedentary lifestyle makes us vulnerable to many forms of physiological changes that are not natural. In one or another way, these changes inevitably impacting the hormonal balance and eventually circadian rhythms and psychological stress.
Along with the unnatural eating and drinking habits, altered circadian rhythm, and stress are known to cause epigenetic changes. Briefly, epigenetic changes refer to those changes that affect the way your genes work, in other words, how our body reads a DNA sequence.
Unlike the common form of genetic changes or mutation, epigenetic changes are reversible and do not originate from a permanent alteration in DNA sequence. Nevertheless, a lasting epigenetic change in one’s cell can cause permanent damage to a gene expression and could be passed down to the next generation.
In summary, because of our lifestyle we are vulnerable to induce genetic “mutation” of one or another type that might appear as a genetic disorder in our next generations. This could be one of the reasons that we find hereditary links to lifestyle related genetic disorders.
And here it may not sound ridiculous if we want to take a lesson from animals. As forest animals follow their natural animal lifestyle and remain healthy, we also need to live our natural human lifestyle to remain healthy. The further we are away from our natural human lifestyle, the more we are vulnerable for epigenetic changes and eventually more genetic disorders.
Does it mean that we have to go back to the lifestyle of our earlier generations? The answer could be yes and no. While we ought to continue and embrace technological advancements, we also should not compromise what is needed for us to live a healthy life by keeping a natural lifestyle.
Hence, it is important to ask, how much of those dynamic challenges that we invite for (read: impose on) ourselves in the name of technological advancement that are out of necessity, and how much of those that are out of our ignorant indulgence.
If the progress in civilization means vulnerability to more and more genetic disorders, then what shall we live for?
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The author is the Associate Dean (Continuing Education), Faculty of Dentistry, and Associate Member, UM LEAD, Universiti Malaya. He may be reached at tarique@um.edu.my
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