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    Sneezing Sponges! Did They Evolve Noses?
    By Hank Campbell | February 7th 2014 03:30 AM | 3 comments | Print | E-mail | Track Comments
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    Evolutionary biology sounds exciting - there wouldn't be any movies on the SyFy Channel without Gatoroids and Sharknados and other feats of life science run amok - but in reality you are going to spend a lot of time paying your dues watching sponges in mid-sneeze before you get to create an epidemic or a giant monster.

    Sneezing sponges? Isn't that a little far-fetched, even for the network that brought us "Arachnoquake"? No, actually the sponge thing is real, and a new paper points to Porifera sneezing as evidence for a sensory organ in one of the most basic multicellular organisms on Earth, even though it doesn't even have a nervous system to interpret sensory information.

    Sponges are pretty simplistic, at least in regards to how we see life. They feed by channeling water through their bodies. They have no digestive or circulatory systems, they live and die by water circulation alone. No noses, because there is no nervous system, so it would be pointless.

    Right?

    Sponges do sneeze, according to Sally Leys, Canada Research Chair in Evolutionary Developmental Biology at the University of Alberta. It takes about 45 minutes and involves an entire body-wide contraction. It's a sneeze because it reacts to stimuli like we do when we sneeze, in this case something like physical sediment.

    Don't believe it? They took this video, one image every 30 seconds, after adding sediment to the water it is filtering. 


    Credit: Danielle Ludeman

    The researchers used a variety of drugs to cause sneezing and then observed the process using fluorescent dye. They focused on the sponge’s osculum, which controls water exiting the organism, including when it sneezes. Their paper says they found that a cellular version of cilia, which function line antennae in other animals, play a role in triggering the sneezes. They concluded that the presence of ciliated cells in the osculum, combined with an apparent sensory function, means the osculum could be a sensory organ.

    “For a sponge to have a sensory organ is totally new. This does not appear in a textbook; this doesn’t appear in someone’s concept of what sponges are permitted to have,” said Leys.


    Cilia on the epithelia lining the osculum. a. The sponge Ephydatia muelleri in the lake, and grown in the lab viewed from the side (upper inset) and from above (lower inset). The oscula (white arrows) extend upwards from the body. b, c, Scanning electron micrographs show cilia arise from the middle of each cell along the entire length of the inside of the osculum; b the lining of the osculum with cilia on each cell (inset shows an osculum removed from the sponge and sliced in half longitudinally); c, two cilia arise from each cell. d, e, Cilia in the oscula labeled with antibodies to acetylated α-tubulin (green), nuclei with Hoechst (blue, n), actin with phalloidin (red). f. A 3D surface rendering illustrates how the cilia arise just above the nucleus of the cell. Scale bars a 5 mm; inset 1 mm; b 20 μm; inset 100 μm c, 1 μm d, 20 μm e, f 5 μm. Credit: doi:10.1186/1471-2148-14-3

    The fun thing about evolutionary biology is that there are always a lot of new things to learn. This raises new questions about how sensory systems may have evolved.  This could be unique and have evolved over 600 million years, or it could be evidence of a common evolutionary history.

    “The sneeze can tell us a lot about how the sponge works and how it’s responding to the environment,” said lead author and evolutionary biology graduate student Danielle Ludeman in their statement. “This paper really gets at the question of how sensory systems evolved. The sponge doesn’t have a nervous system, so how can it respond to the environment with a sneeze the way another animal that does have a nervous system can?”

    We look forward to the answer.

    Citation: Danielle A Ludeman, Nathan Farrar, Ana Riesgo, Jordi Paps and Sally P Leys, 'Evolutionary origins of sensation in metazoans: functional evidence for a new sensory organ in sponges', BMC Evolutionary Biology 2014, 14:3 doi:10.1186/1471-2148-14-3

    Comments

    More and more information is being revealed on how humans evolved from more simple organisms. If this is researched even further and it is proved that something as specific as a sneeze can be pinpointed as arising in a certain organism, the evolutionary theory will only progress further. Fossils of the first organisms such as sponges, were proved to be dated back to 635 million years ago. (Van Der Rest and Garrone 1990) Evolution and how exactly it took place is and probably always will be a very argued topic in science. The fact that a trait such as a sneeze was found in them and they are such an ancient animal, may suggest that the trait originated with them which can help with the evolutionary theory. More evidence on the similarities between these organisms are the fact that they are multicellular, have some sort of skeleton, and are able to live well with bacteria living inside them. (Green 2003) The sponge being the more simple of the two species, can tell us that at some point or another we had to have started out on their level of complexity and continuously involved keeping some and getting rid of most traits. If a trait such as a sneeze was one to stay around that is remarkable.

    D. Green, D. Howard, X. Yang, M. Kelly, and R.O.C. Oreffo. Tissue Engineering. December 2003, 9(6): 1159-1166. doi:10.1089/10763270360728062.

    This is absolutely amazing that something like this could happen. Without a nose, you would think that sneezing would be impossible. Since something as simplistic as a sponge can sneeze like this, it makes a person wonder if this is where this particular trait or gene came from for modern day animals. Like the person above stated, this could help immensely with tracing back evolution. I believe that this is a trait that is coming from millions of years ago because this sort of sneeze is obviously not the same as a human or other animal sneezing which could also prove that the trait had evolved. This is still blowing my mind, and I would like to read more about this!!!

    Herne Webber
    How is this different from touch-induced movement in carnivorous plants?  Given a complete lack of nervous system, obviously the cell-to-cell transmission (pre-nerves) is how the information about what is happening is shared within the organism.  Trees have been shown to 'react' to a leaf being removed by their bioelectric field contracting, then re-expanding.  Such things are akin to our reflexes, but are more primitive, working without specialised transmission cells (nerves), and without a centralised organ with which to interpret and later act upon the data input from these 'senses.'

    Obviously for organisms which can't move to develop complex sensory adaptations would be pointless.  Plants and sponges likely do not sense pain in any way as we do, because they cannot respond to it.  Which came first, the ability to get sensory data, or the ability to respond to it?  Or could both components arise independently, and become linked together later on in evolution?  For animals who *can* move, in fact, who *must* move to eat or escape being eaten, clearly light sensitivity, chemo-senses, as well as electro-senses in the water can become very adaptive.  Single-celled animals react to all of these sorts of things, all without anything but their intracellular matrix a perhaps a specialised organelle or two.  Animals that become anchored should in theory lose some of those senses, because they are of no use.  So in this light, the ancestors to the sponges probably had some sensory abilities the porifera later lost.  Rather than seeing the emergence of a sense, we are witnessing the tail end of it.
    P.S., this is *not* related to the human sneeze reflex in any "we are related" evolutionary way.  Our ancestors did not develop from the sponges.  But convergent evolution can create and re-create similar responses for similar purposes; in this case, forceable venting of foreign material.  Considering they also eat in the same system that they breathe, one could have just as easily declared this to be a sponge vomiting, or letting a fart.  Now a *farting* sponge would be a real attention-getter.