Our ancestors had two nostrils, one front and one back, but no opening on the palate or in the throat. They could smell, but not breathe with their nose. How did our nose evolve? Per Ahlberg, Uppsala university, and Zhu Min, department of Vertebrate Paleontology in Beijing, China, has now found a fossil that explains the history of the nose.
Have you ever wondered, taking a deep breath of fresh autumn air and sensing how the smell of wet leaves tickles your nose, just how it came about that you can do so? We humans take it for granted that our nose forms a passage between the world around us and our windpipe, but this hasn’t always been the case. We land-based vertebrates or “tetrapods” (mammals, birds, reptiles, and amphibians) originally descend from fish, and fish cant breathe through their nose. On the side of a fish’s head there are two nostrils, one front and one back, that form the opening to a little sac containing the olfactory organs: water flows in through the front nostril and out through the back one, but there is no connection whatsoever to the throat. In other words, fish can smell with their nose, but not breathe.
We tetrapods may have only one external nostril on each side of our head, but we do have an inner nostril or “choana” that opens on the palate or in the throat. This is what makes it possible for us to breathe through our nose. But how did this inner nostril evolve? One thing all scientists agree about is that the front nostril in fish corresponds to our single outer nostril: the question is whether the back nostril was transformed into our choana by “migrating” to the palate, or whether the choana is a new opening that arose with tetrapods.
Anneli Waara | alfa
Surprising similarity in fly and mouse motion vision
30.07.2015 | Max Planck Institute of Neurobiology, Martinsried
Intracellular microlasers could allow precise labeling of a trillion individual cells
30.07.2015 | Massachusetts General Hospital
Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.
The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...
Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.
Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight
A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...
Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.
By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...
Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.
While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...
23.07.2015 | Event News
10.07.2015 | Event News
25.06.2015 | Event News
30.07.2015 | Awards Funding
30.07.2015 | Life Sciences
30.07.2015 | Health and Medicine