Latest research falsified the age-old belief that the human sense of smell just isn't at par with our canine companions'. How exactly did the human sense of smell evolve?
Age-Old Myth Debunked
As far as many people know, the human sense of smell isn't really exceptional. However, latest study has shown that in some ways, the human sense of smell is just as good as dogs'. Apart from comparing human cell receptors from other creatures, author of the study John P. McGann also traced back the origin of the belief regarding humans having a substandard sense of smell.
What McGann found and shared in his study is that the assumption simply based the quality of the human sense of smell merely on the number of smell receptors compared to other animals such as rats and dogs. Simply put, McGann's study explained that regardless of the differences in the number of smell receptors, humans are more sensitive to certain scents while other mammals are more sensitive to others.
How Did The Human Sense Of Smell Evolve?
Though humans came late into earth's history, our ancient ancestors did a whole lot of evolving before we became the human race as we are today. That means that the human body, including our sense of smell, also changed to adapt to the surrounding conditions.
A study about ancient human sense of smell sheds light into how the human sense of smell evolve and how our ancestors would have used their own sense of smell.
A specific smell receptor called OR7D4 allows humans to smell a specific scent called androstenone, a scent produced by pigs and can be found in boar meat. Though all humans have the receptor to detect this smell, people actually respond to it differently with some people finding it foul, others finding it sweet, while some cannot smell it at all.
What's interesting is that the variations in the way people smell androstenone are based on their DNA codes. For example, people in Africa tend to be able to smell androstenone, while those from the northern regions likely can't.
One possible explanation for this sense of smell discrepancy relates to extinct human cousins, the Neanderthals and the Denisovans. An analysis of Neanderthal DNA showed that they, too, could detect the scent. On the other hand, though the Denisovan DNA showed that they can also smell androstenone, their DNA also showed a unique mutation that changed the structure of their OR7D4 receptor.
Though close human relatives could all smell the unique scent, the research shows that studying our DNA can possibly give some insight as to how modern human tastes in food may have been influenced by our differences in ability to smell.
As shown by the differences in the ability to detect the smell of androstenone between people in Africa and people in the Northern regions, perhaps our ancient ancestors' dispersion from Africa also caused various changes in our sense of smell.