Human beings have been impressed by the mystery of bioluminescence long before the time of Aristotle. And Charles Darwin himself called this phenomenon puzzling. Why have some creatures evolved to produce light, while other similar creatures have not? Bioluminescence, by definition, seems boring and uninteresting. It is the chemical creation of light by living organisms. However, seeing it raises questions and stimulates the imagination. How did these creatures develop this ability, what is its function, what chemicals are responsible for this incredible light show, and how can we use it to benefit humanity? Oddly enough, not all creatures that glow are related. Their bioluminescence has evolved individually and provides a whole series of different functions depending on the organism (Wilson.1998. p. 197). As for why this ability evolved, scientists can only speculate. The commonly ruled out theory is that because the ocean, where most bioluminescent species live, is dark or in some cases completely devoid of light, these species have adapted to their (city) environment. While on land bioluminescence is rare, fireflies and glow worms for example, in the ocean it is business as usual. Over fifty percent of jellyfish are bioluminescent, the most common vertebrate in the sea, the curved-toothed mouth, is bioluminescent and even some species of sharks flash their lights to attract an easy meal (Widder. 2014. para 2) . Darkness is something that we humans are not comfortable with, but for bioluminescent creatures it can prove extremely useful. They use their lights for a variety of necessary activities, ranging from long-distance communication and reproduction to protecting and capturing their prey. To...... middle of paper ...... and Atmospheric Administration. Retrieved from http://oceanservice.noaa.gov/facts/biolum.html.Wilson T., Hastings W. 1998. BIOLUMINESCENCE. Department of Molecular and Cellular Biology, Harvard University. Retrieved from http://ezproxy.philau.edu:2430/pdf17_20/pdf/1998/2SZ/01Nov98/5366022.pdf?T=P&P=AN&K=5366022&S=R&D=aph&EbscoContent=dGJyMNHr7ESeqK44v%2BbwOLCmr0yep7RSrqi4S bCW xWXS&ContentCustomer=dGJyMPGqrlCyr7FNuePfgeyx34Tq5ewA.Young, R Ocean bioluminescence: an overview of general functions. : Bulletin of Marine Science, Volume 33, Number 4, October 1983, pp. 829-845(17). Retrieved from http://www.ingentaconnect.com/content/umrsmas/bullmar/1983/00000033/00000004/art00003.Yong, E. January 2013. What is this great white shark? National Geographic. Retrieved from http://phenomena.nationalgeographic.com/2013/01/23/what-bit-this-great-white-shark-a-cookie-cutter/.