Human ancestors explored 'out of Africa' despite impaired nasal faculties

March 24, 2016, Public Library of Science
Human ancestors explored "Out of Africa" despite impaired nasal faculties. In humans inhaled air is conditioned poorly in the nasal cavity in comparison with primates, such as chimpanzees and macaques, according a recent study published in PLOS Computational Biology. Credit: Nishimura et al.

In humans inhaled air is conditioned poorly in the nasal cavity in comparison with primates, such as chimpanzees and macaques, according a recent study published in PLOS Computational Biology. Unlike our protruding external nose, which has little effect on improving air conditioning performance, other hominins (including australopithecines) were endowed with flat nasal features and faculties to improve air conditioning.

The study, produced by Dr Takeshi Nishimura from Kyoto University and colleagues, is the first investigation of nasal in nonhuman hominoids based on (CFD).

The human nasal passage conditions inhaled air in terms of temperature and humidity to match the conditions required in the lung. Insufficient conditioning can damage the tissues in the respiratory system and impair respiratory performance, thereby undermining health and increasing the likelihood of death.

Our ancestors, the genus Homo, diversified under the fluctuating climate of the Plio-Pleistocene, to be flat-faced with a short and a protruding external nose, as seen in modern humans. Anatomical variation in nasal region is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat, but the nasal anatomy of early Homo was not sensitive to the ambient atmosphere conditions. The inhaled air can be fully conditioned subsequently in the pharyngeal cavity, which was lengthened in early Homo.

This study highlights the importance of compensating human evolution, as well as adaptive evolution. The diversification of Pleistocene hominins is a major evolutionary event in terms of understanding human evolution. These linked changes in the nasal and pharyngeal regions would in part have contributed to how flat-faced Homo members must have survived fluctuations in climate, before they moved "Out of Africa" in the Early Pleistocene to explore the more severe climates and ecological environments of Eurasia.

Explore further: Nasal, pharyngeal EPX levels linked to sputum eosinophilia

More information: Nishimura T, Mori F, Hanida S, Kumahata K, Ishikawa S, Samarat K, et al. (2016) Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo. PLoS Comput Biol 12(3): e1004807.DOI: 10.1371/journal.pcbi.1004807

Related Stories

Nasal, pharyngeal EPX levels linked to sputum eosinophilia

December 16, 2015

(HealthDay)—For individual patients with poorly-controlled asthma, nasal and pharyngeal eosinophil peroxidase (EPX) levels are strongly associated with the eosinophil percentage of induced sputum, according to a study published ...

Dinosaurs used nasal passages to keep brains cool

October 22, 2015

Dinosaur nasal passages were certainly nothing to sneeze at. Possessing among the largest and most complex nasal passages seen in animals, their function has puzzled paleontologists. New research suggests that the size and ...

Nasal congestion: More than physical obstruction

October 13, 2011

Nose feel congested and stuffed up? Scientists from the Monell Center report that the annoying feeling of nasal obstruction is related to the temperature and humidity of inhaled air. The findings suggest that sensory feedback ...

Research aids nasal drug delivery

February 17, 2012

RMIT University researchers have developed computer models to design more effective nasal sprays to provide alternate drug delivery to needles or pills.

Recommended for you

Scientists crack genetic code of cane toad

September 19, 2018

A group of scientists from UNSW Sydney, the University of Sydney, Deakin University, Portugal and Brazil have unlocked the DNA of the cane toad, a poisonous amphibian that is a threat to many native Australian species. The ...

Scientists examine variations in a cell's protein factory

September 19, 2018

You can think of a cell in your body like a miniature factory, creating a final product called proteins, which carry out various tasks and functions. In this cellular factory, genes control the series of sequential steps ...

Why some animals still have a penis bone

September 19, 2018

A team of researchers affiliated with several institutions in the U.K. has found a possible explanation for why some animals still have a penis bone—"prolonged intromission." In their paper published in Proceedings of the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.