What are the major evolutionary pressures for Bioluminescence?
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11$\begingroup$ In which organisms? Certainly mushrooms, glowworms, and dinoflagellates illuminate for different reasons... $\endgroup$– user132Commented Dec 18, 2011 at 9:13
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$\begingroup$ Sorry for not being specific. I was mostly curious about deep sea. Should I break this up into separate questions? $\endgroup$– Aleksandr LevchukCommented Dec 20, 2011 at 2:20
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$\begingroup$ This question is close to my heart since I saw the Phosphorescent Bay in SW Puerto Rico. Its interesting to contrast the deep ocean with fresh water caves, where the fish become blind / eyeless. The difference might simply be a lack of phosphorescent microorganisms to provide the light for the fish, or maybe the distant connection to the surface allowed the phosphorescent algae to influence the sunless deep parts of the ocean. $\endgroup$– shigetaCommented May 30, 2012 at 20:29
2 Answers
In many cases, and in particular in marine invertebrates, the bioluminescence is in fact produced by symbiotic bacteria of the Vibrionaceae family. In most cases the bacteria can sense when they are being hosted by the animal through quorum sensing mechanisms, and start producing light.
The evolutionary pressure for the bacteria to produce light is to be in the protected environment of the animal which often feeds them. On the animal side, there can be several reasons to host the luminescent bacteria. In many cases, the evolutionary pressure is linked to reproduction. In order to successfully reproduce in the immensity of oceans, marine animals need to know that they are among their kind before they release their gametes.
Another example is the one of some deep see fish like the anglerfish which have developed a special "flash light" organ to host bio-luminescent bacteria. Fish can use the bacteria to emit a light to aid in camouflage, hunting, and attracting mates. See http://microbewiki.kenyon.edu/index.php/Deep_sea_fish
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1$\begingroup$ Whilst it's not exactly academic, the BBC documentary "Blue Planet" had an excellent episode on deep-sea creatures, containing a large section about bioluminescence. Well worth a watch. $\endgroup$ Commented Dec 18, 2011 at 22:18
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1$\begingroup$ No matter the reason the "Blue Planet" is always worth watching. $\endgroup$– AnnaFCommented Dec 19, 2011 at 17:10
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$\begingroup$ @Polynomial In fact, the II came out about three years ago, but I haven't been able to see it yet. $\endgroup$ Commented Jul 27, 2021 at 22:59
Bioluminescence, in particular in marine organisms, has also been linked to way to get rid of reactive oxygen species (ROS). In fact, luciferases catalyse the photogenic oxydation of luciferins. In [1], the authors propose that this system's function was primarily for antioxydation, while in deep seas, where the water is oxygen-poor, the lower selective pressure toward antioxydation would have given rise to light emitting functions in specialized organs.
Bioluminescence in the Ocean: Origins of Biological, Chemical, and Ecological Diversity