When it comes to sniffing, humans aren't very good at it. Inhaled air is conditioned poorly in the nasal cavity in comparison to other primates, such as chimpanzees and macaques. Now, scientists have taken a closer look at human nasal passages conditions to learn a bit more about our ancient ancestors.
In this latest study, the researchers looked at nasal air conditioning in nonhuman hominoids based on computational fluid dynamics (CFD).
The human nasal passage actually conditions inhaled air in terms of temperature and humidity in order to match the conditions required in the lung. In fact, insufficient conditioning can damage the tissues in the respiratory system and impair respiratory performance. This, in turn, can undermine health and increase the likelihood of death, according to the study.
Our ancient ancestors evolved under the fluctuating climate of the Plio-Pleistocene. During this time period, the genus Homo was flat-faced with a short nasal cavity and protruding external nose, which is similar to what is seen on modern humans. Variation of the nasal region was likely depending on the ambient atmospheric conditions of a given habitat.
While the nasal formation was dependent on climate, the researchers found that the actual nasal anatomy of early Homo was not sensitive to the ambient atmospheric conditions. The inhaled area can be fully conditioned subsequently in the pharyngeal cavity, which was lengthened in early Homo species.
The findings reveal a bit more about our ancient ancestors. More specifically, it highlights the importance of examining human evolution, as well as adaptive evolution.
The diversification of Pleistocene hominins is a major evolutionary event in terms of understanding human evolution. This means that looking at perceived small changes, such as the human nose and nasal passages, is extremely important when understanding what changes ancient humans underwent and how climate may have impacted their adaptation.
The latest study not only shows a bit more about human evolution, but also shows that the changes in the nasal and pharyngeal regions would have partly contributed to how Homo members survived fluctuations in climate before moving from Africa in order to explore the more severe climates found in Eurasia.
The findings are published in the March 2016 journal PLOS Computational Biology.
