Science
Human Evolution and Snoring
Snoring can be seen as an unfortunate by-product of human evolution. Specifically, our airway is a victim of speech and upright posture.
The human throat has too many functions to do any of them perfectly, and instead does everything adequately.
This small section of our body needs to be able to breathe, swallow and generate speech, switching between the three processes seamlessly – all whilst supporting a head with a heavy human brain.
There are bound to be conflicts of interest. Snoring is that conflict making itself known.
Here’s why you can (sort of) blame Darwin for your snoring problem …
Problem #1 – Speech
To breathe at optimal efficiency (and not snore) our airway would need to be a long, straight, rigid tube structure.
Unfortunately, this design is not compatible with generating speech which requires almost the exact opposite qualities. To achieve the diverse range of sounds unique to human speech, a flexible tongue and upper airway are required.
Perfect breathing and sophisticated speech are simply incompatible so a compromise is needed.
To vocalise beyond the grunts of our pre-human ancestors, some different facial characteristics are necessary. First, a longer neck to accommodate more sophisticated sound apparatus is required. This means more soft, muscular tissue unsupported by the harder structures of the skull. Such floppy tissue is snoring waiting to happen.
Our tongue works by shaping the sounds generated lower down the throat in the larynx. To do so, it has to sit further back in the mouth compared to other mammals. It therefore rests precariously close to the back of our upper airway and risks causing obstruction if it relaxes too much.
Problem #2 – Upright posture
By standing on two legs we need a precise center of gravity to keep us from toppling over. Evolution has achieved this with changes to hip structure, thigh angle and spinal curvature.
Additionally, our neck needs to be optimally positioned to support the skull and the heavy brain within. Hence, humans’ throats are more centrally located underneath the skull. This is contrary to other mammals, where the throat sits further forward in a nicely spacious neck.
Overall, there is less space to fit more material. These conditions are perfect for partial airway obstruction – the underlying culprit for snoring.
Problem #3 – Creature comforts
Having anatomy primed for snoring isn’t usually enough to condemn us to a lifetime of nocturnal noise. Instead, an obstruction trigger is needed. As humans have become more advanced, living in more comfort, we have introduced many potential obstructions.
The prime example of this is weight. In the developed world, humans now have ready access to food – sometimes too much of it. Excess weight around the neck and chest is one of the biggest causes of snoring.
Other uniquely human vices such as smoking and alcohol consumption set up snoring perfectly.
Why hasn’t natural selection rid us of snoring?
The concept of evolution and natural selection suggests that advantageous characteristics persist, whereas disadvantages disappear over time. This is known as “selection pressure”. Snoring is surely disadvantageous, so why hasn’t evolution gotten rid of it yet?
These days, being preyed upon isn’t something many humans have to worry about. Therefore, snoring and giving away your location in the vulnerable state of sleep is unlikely to see you snuff it at the hands of a hungry predator.
It is arguable that snoring confers an evolutionary disadvantage as it could be an undesirable quality in a mate – simply, snorers are less likely to find a partner and pass on their “snoring genes”.
Is snoring genetic?
In reality, this notion is clearly flawed. Snoring appears to confer no evolutionary disadvantage whatsoever.
Even if snorers couldn’t find partners, many snorers are late to the party – only snoring in older-age once they have had plenty of opportunity to pass on their “snoring traits”.
Hang on, other mammals snore too
It is true that humans aren’t the only snorers in the animal kingdom. Anything with soft tissue in its airway is prone to snoring – i.e. all mammals.
The internet is awash with cute videos of snoring animals. Further, we often get asked if SnoreLab will detect pets’ snoring.
Snoring amongst wild animals is poorly understood (do you really fancy sneaking up on a pride of lions at night to have a listen?) but it seems that snoring in animals tends to be at least in-part the result of domestication.
The most prevalent non-human snorers are animals where humans have had a hand in their creation – namely dogs bred with features that cause breathing difficulties (e.g. pugs and bulldogs).
Domestic animals also have a higher chance of overeating and don’t face predation like their wild counterparts where snoring could be an evolutionary disadvantage.
Conclusion
So whilst snoring isn’t a uniquely human problem, the features that enable us to speak and walk on two feet have knock-on effects.
Modern humans are not an end-point; we are merely a snapshot in an evolutionary story with much history and an interesting future (which may or may not include snoring). For the time being, snoring seems to be here to stay – that is unless we can help!
