Jillian's Current Event

Earth Science                                                                                     March 13, 2014

Current Event                                                                                   Jillian Jiampietro

                                    Take a Breath and Thank a Sponge

work cited: Zimmer, Carl. "Take a Breath and Thank a Sponge." The New York Times. The New York Times, 17 Mar. 2014. Web. 13 Mar. 2014.

http://www.nytimes.com/2014/03/18/science/take-a-breath-and-thank-a-sponge.html?src=me&_r=2

The article I decided to analyze was entitled, Take a Breath and Thank a Sponge, written by Carl Zimmer. Before I read this article, I thought of sponges as just a species that lived its life on the sea floor trapping bits of food, yet this article proves to me that sponges had a crucial role in the development of all species on Earth and the rise of the Animal Kingdom.

            Dr. Lenton, an earth systems scientist at the University of Exeter, was the one who first formed the hypothesis that sponges played a very important role in the evolution of all species. Dr. Lenton and his colleagues believe that over 700 million years ago, sponges transformed the planet by releasing a mass amount of oxygen into the ocean. Before this great unleash of oxygen, there was barely any oxygen in the Earth’s atmosphere and almost none in the ocean as well. A man named Donald E. Canfield decided to run an experiment to see how little oxygen sponges need to survive. His results stated that sponges could handle surviving with 17 percent oxygen in the atmosphere, which is about 4 percent less than the average level. Dr. Canfield’s data proves that sponges could have evolved many years before oxygen levels were even close to a comfortable level. More evidence that proves this hypothesis is that scientist found fossils and chemical traces of sponges that date back as far as 700 million years, which is way before the ocean gained much of its oxygen. Even though the evidence proving Dr. Lenton’s theory is plentiful, there were theories formed before that argued against Dr. Lenton’s theory. This important past hypothesis was made by John Ralph Nursall in 1959. Dr. Nursall’s hypothesis stated that the evolution of animals had been blocked because Earth had to accumulate enough oxygen to support them. This argument was based on the fact that living animals consume lots of oxygen to run their bodies. Yet his hypothesis that animal could not evolve on low oxygen Earth has been challenged by recent studies, including Dr. Canfield’s study. Dr. Canfield was a big supporter of Lenton’s hypothesis, saying that Dr. Lenton’s paper correctly explained the evidence scientists have gathered so far about the history of animals and ocean. Yet Dr. Lenton's theory goes even deeper into the idea that not only did sponges exist at low level’s of oxygen, but that the first animals themselves were responsible for raising the levels of oxygen in the ocean, which caused more complex life to be formed. For instance, billions of years ago the ocean’s surface was covered in photosynthetic bacteria, yet this bacteria was eaten by predatory microbes that caused the ocean to remain oxygen free. Yet later this changed with algae and other large single celled organisms began to evolve. When the algae and single celled organism got bigger and died, they would sink deep into the ocean. Then down at the bottom of the sea would be the sponges that acted as seawater filters that trapped organic matter and lowered nutrients in the water like phosphorus. Since sponges consumes the phosphorus, their would be none for the bacteria to go through photosynthesis, allowing algae to gain more oxygen which it then would produce into the deep levels of the ocean. Sponges are what made a new environment with an oxygen rich ocean and new animals possible, and with new animals forming meant more ways for oxygen to be formed and so on. These detailed hypothesis created by scientists are believed to be only a few of the crazy ideas that are going to be thrown our way about the interesting history of oxygen and animals.

            This article connects to society today because without the transformation of the level of oxygen, we might not be alive today. These theories gathered on what sponges might have done to start the Animal Kingdom is what makes all different species and the different theories on how life began so interesting. As stated my Dr. Lenton in this article, “This story is about the first animals bootstrapping the environment into one where more complex animals could evolve. This is essentially the birth of the modern world.”

            I found this article to be fascinating because it is proving that a brainless species could have played a crucial role in the forming of human kind and all the species before us that rely on oxygen. I found it confusing on what Dr. Lenton’s actual hypothesis was in some areas of the article since there were many different factors to what he was trying to prove so I think it would have been a good idea to specify what Dr. Lenton actual hypothesis was. Yet, I still found that it gave great information for both sides of this ongoing argument on whether animals, like sponges, could live in low levels of oxygen and if they did actually have an important part in raising the oxygen levels on earth.