Human Noses are Climate-Adapted! Can I get a bigger one for Houston?

There has been much speculation, research, and debate regarding how human nose size and shape signifies adaptation to various climates. It is a relatively well-accepted fact that populations that evolved in warm climates possess large, wide noses with big openings to aid in cooling the body, while humans in cold climates have evolved narrow noses that warm and moisten air before it reaches the lungs.

 

But Neanderthal noses have been extremely confounding in our understanding of how nose size can respond to selection pressures from climate. The Neanderthal is widely recognized as its own extinct hominid group, though it is still debated whether it should be designated as an extinct form of Homo sapiens or as its own species, Homo neanderthalensis. Despite this debate, clues from the Neanderthal nose can still be useful indicators of human evolution, since the Neanderthals is undoubtedly a card-carrying (spear-carrying, perhaps?) member of the Homo classification, owing to its large brain volume and other characteristics. So, back to the nose: the reason the Neanderthal nose is so bewildering is that Neanderthals are known to have had wide noses with extremely large openings. Since they inhabited glacial Europe thousands of years ago, their large open noses seem contradictory to modern evolutionary thought. Until recently, it was believed that oversize Neanderthal noses corresponded to extra-lengthy sinuses, which could actually serve to warm the cold ambient air before it reached the lungs. However, in 2011 it was proven that Neanderthal sinuses were comparable in size to our own, indicating that their large noses must have been more parallel in function to those of modern humans from tropical regions, whose noses are clearly involved in cooling functions. 

A Neanderthal nose

So what can explain the seemingly incongruous large nose of a cold-dwelling human ancestor? Well, Neanderthals may not have been such extreme-weather conquerors after all. While the image of a hairy, fur-clothed, wolly-mammoth-hunting caveman is familiar to all of us, the nasal peculiarities of Neanderthals suggest more temperate origins. Combine the large nose, standard-sized-sinuses, and recently discovered plant-matter-caked-teeth of the Neanderthal, and we have ourselves a species best adapted to warmer climates. Did the Neanderthal, then, originate in warmer regions and migrate to the cold? Could their warm weather noses have contributed to their being maladapted to freezing temperatures, and thus played a part in their demise during the last European Ice Age ? With the confounding Neanderthal noses explained, the pattern of climate-adapted facial features in modern humans remains clear, and nose size can generally be tied to region of origin. But with the liberal use of climate control and the extreme population mixing that characterize our modern world, who knows what the nose knows anymore! 

-Hannah 

Sources:

picture:http://brendans-island.com/blogsource/20101015ff/NeanderthalNose.jpg

Gray, Richard. "Neanderthals Were Not Ugly Because of the Cold, New Research Finds." The Telegraph, 16 Jan. 2011. Web. 14 Mar. 2012. <http://www.telegraph.co.uk/science/science-news/8261609/Neanderthals-were-not-ugly-because-of-the-cold-new-research-finds.html>.

Laitman, Jeffrey T., Joy S. Reidenberg, Samuel Marquez, and Patrcik J. Gannon. "What the Nose Knows: New Understanding of Neanderthal Upper Respiratory Specializations." Proceedings of the National Academy of Sciences 93.20 (1996).JSTOR. Web. 14 Mar. 2012.

Russell, Mark. "Unlocking the Mystery of Neanderthals' Big Nose." Newser. 17 Jan. 2011. Web. 14 Mar. 2012. <http://www.newser.com/story/109870/unlocking-the-mystery-of-neanderthals-big-nose.html>.