Sunday, January 29, 2017

Zebra Shark Surprises Scientists by Giving Birth without Male.

Evelyn Kluemper
1/30/17
AP Biology

Cummins, Anna. "Zebra Shark Surprises Scientists by Giving Birth without Male." CNN. Cable News Network, 17 Jan. 2017. Web.

Anna Cummins’ article, “Zebra Shark Surprises Scientists by Giving Birth without Male” was an interesting case of an animal changing its reproductive strategy.  In an aquarium in Queensland, Australia, zebra shark Leonie was separated with her male mate and was soon joined by Lolly, one of her female pups.  Nearly two years after being separated from zebra sharks, both laid eggs, which according to experts, is not uncommon.  Biologist Christine Dudgeon said that “It’s much like a chicken-- they lay eggs whether they are fertilized or not, if the conditions are good” (Cummins).  However, despite efforts made by the aquarium, the embryos in several eggs were unable to survive.  The following year, subsequent to laying eggs, Leonie produced three hatchlings and Lolly two.  It is not uncommon for vertebrates to be able to reproduce without fertilization, an advantageous characteristic that is believed to have been acquired evolutionarily through years of isolation.  However, this is the third known case of a vertebrate to switch its reproductive strategy.  The first two instances were an eagle ray and a boa constrictor.  Scientists have observed that the genes of the hatchlings have a great frequency of homozygosity and little to no genetic variation, which is a great disadvantage, as they are unable to adapt to their environment as well.
Biologists will be observing the hatchlings to see if they are able to reproduce sexually, since asexually produced offspring in the past have been unable to do so.  This birth will help biologists discover if it is possible for more species to reproduce without males.  Additionally, zebra sharks are considered an endangered species, so an alternative way to reproduce could greatly impact population numbers.

The article was very interesting to read and included an informative video.  It described the circumstances in which the zebra sharks reproduced asexually.  The author included a statement given by an expert.

10 comments:

  1. I read the review of and the article “Zebra Shark Surprises Scientists by Giving Birth without Male” by CNN and I found it very interesting. I liked how the author made the article personal by mentioning the name of the Zebra Shark that gave birth without a male; it made the article more interesting and relatable. Also, I liked how the author of both the review and the article mentioned how it was possible for a shark to reproduce others without fertilization, it mentions that this characteristic was obtained over many years of isolation, which is natural selection. Lastly, I liked how the authors mentioned that this event is not particularly uncommon. This has happened to several other species, including and eagle ray and a boa constrictor. Overall, I enjoyed reading this article and it had many positive aspects.
    Even though there good aspects of this article, it also had its negatives. First, I did not like how the author did not mention what scientists are planning to do regarding this discovery, like what more research they plan to do and uncover. Also, I did not like how they did not mention the science behind this discovery, like how animals are even able to reproduce asexually and why these certain animals are only able to do it. Although this article had some negative aspects, I really enjoyed reading it.
    I learned a lot from reading this article. First, I learned that it was even possible for animals to reproduce asexually and without fertilization, I thought all animals could only reproduce with fertilization. Also, I learned how beneficial this way of reproduction could be. Zebra Sharks are an endangered species of animals, and being able to reproduce asexually could save their species by producing much more offspring. Overall, I really enjoyed reading this article and I looks forward to learning more about this subject in the future.

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  2. Charlotte Prior
    Current Event 15
    1/29/17

    I read Evelyn's review on the article, “Zebra Shark Surprises Scientists by Giving Birth Without Male.” I think that this article is very interesting and Evelyn did a good job in picking something that is new and a topic relevant to what we are studying. She also did a good job of not talking excessively in her review and she kept the words to a minimum so that the reading was simple and easy. I also did not notice any spelling or grammatical errors that made the review hard to read, which was great.

    One thing that I think Evelyn could improve on is elaborating on why the evolutionary changes occurred, and how it changed the life of the animal. She could also add some more to her opinion of the article and whether or not she liked the author's point of view.

    This was an interesting review to read and it was a story I had never heard of before. And I find it very surprising that the shark could reproduce by itself.

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  3. Cummins, Anna. "Zebra Shark Surprises Scientists by Giving Birth without Male." CNN. Cable News Network, 17 Jan. 2017. Web.

    http://www.cnn.com/2017/01/17/health/zebra-shark-reproduction/index.html

    Evelyn wrote a concise and well-written review to the article “Zebra Shark Surprises Scientists by Giving Birth without Male” by Anna Cummins. After explaining the details of the experiment in Queensland where a female zebra shark and one of her pups were both able to lay eggs without being fertilized, Evelyn did a great job of mentioning why reproduction without fertilization is an advantage to vertebrates. She writes that it probably developed over many generations through evolution as a result of years of isolation, which helps the reader to understand that organisms such as sharks can use this method to produce offspring in order to add to the species population if males are absent. Evelyn also included an important quote from biologist Christine Dudgeon that compares the sharks’ reproductive method to that of chickens and describes that it is possible “if the conditions are good.” This helps the reader of the article learn about the conditions necessary for certain organisms to reproduce this way. She also did a great job of including what the biologists at the aquarium plan to do with the hatchlings: observe them to learn if they will reproduce sexually. In this way, Evelyn includes important information related to the experiment and the potential future discoveries of this experiment.
    While Evelyn wrote an excellent current event report, there are some areas that she could improve upon. The first is that she didn’t offer any criticism of the author and her piece, which is necessary for a complete and thorough current event review. If she had included a critique of the article, she could help the reader to fully understand the drawbacks of the article. I thought that Evelyn also should have explained the mechanisms involved in this type of asexual reproduction because her sparse description is incomplete and lacking the necessary details.
    After reading this article and its review, I have learned about an interesting case of an organism changing its reproductive strategy to adapt to its environment and current conditions. It was fascinating to read about the discovery of this method of asexual reproduction in zebra sharks and its implications are very important for preserving zebra sharks in the world and preventing species extinction.

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  4. Cummins, Anna. "Zebra Shark Surprises Scientists by Giving Birth without Male." CNN. Cable News Network, 17 Jan. 2017. Web.
    http://www.cnn.com/2017/01/17/health/zebra-shark-reproduction/index.html


    Evelyn’s review of the article “Zebra Shark Surprises Scientists by Giving Birth without Male” was well written. Her choice of topic was quite interesting and pertinent in the field of biology. Perhaps this phenomenon could be further studied to save certain species from extinction. Second, her summary of the article was thorough yet still to the point. Third, her inclusion of the strength indicated the articles overall tone and added an idea of the expert consensus surrounding the issue.

    While still a strong review, there were a few points of Evelyn’s summary that could have been improved. First, Evelyn could have delved further into the process of this asexual reproduction; this inadequate description left some vital questions unanswered. Second, she could have indicated what this discovery contributes to the scientific community and what researchers plan to do in light of this newfound information.

    The article and review were quite informative. I learned more about asexual reproduction in animals and some of its benefits. The Zebra Shark is doubtless an interesting case study in the field of reproduction.

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  5. I decided to comment on Evelyn’s review of the article “Zebra Shark Surprises Scientists by Giving Birth without Male.” One thing I liked about her review was that she opened the review giving some background. She explains where this event occurred, in Queensland, Australia. Another thing I liked was how Evelyn included references to other animals that most people are more familiar with. For example, she wrote that the way zebra sharks lay eggs is similar to the way chickens lay eggs. Finally, I liked how she discussed other times events like this have occurred. She wrote that this is most likely an evolutionary adaptation and is the third known time that a vertebrae has switched its reproductive strategy.
    Although the article was well-written overall, there were some areas that could have been improved. For example, I found the beginning hard to follow. Her review jumps around making it hard to understand. Another area that Evelyn could have improved was her connection. She explained that this was beneficial to biologists but did not explain how this could impact the common man and how it could be used to prove lives. This made the article feel less personal and helpful to the general public.
    Overall, I thought that the article and Evelyn’s review were extremely well-written and interesting. I was fascinated to learn that events like this could occur. I did not know that it was possible for a vertebrae to produce offspring without a male. It would be very interesting to learn if any other vertebrae could do this and how exactly this knowledge could benefit our understanding of the world around us. It would also be interesting to learn how this might help solve problems such as extinction. I would love to learn about other instances of this happening.

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  6. Cummins, Anna. "Zebra Shark Surprises Scientists by Giving Birth without Male." CNN. Cable News
    Network, 17 Jan. 2017. Web. http://www.cnn.com/2017/01/17/health/zebra-shark-reproduction/index.html

    I read Evelyn’s review of the article “Zebra Shark Surprises Scientists Scientists by Giving Birth Without Male.” The article discussed how two zebra sharks laid eggs without any male zebra sharks. Apparently this is not uncommon and can occur when the conditions are good. This is only the third known case of a vertebrate to switch its reproductive strategy. “Scientists have observed that the genes of the hatchlings have a great frequency of homozygosity and little to no genetic variation, which is a great disadvantage, as they are unable to adapt to their environment as well,” Evelyn stated in her review.

    I chose to read Evelyn’s review because the article seemed interesting from reading the title. I think that Evelyn could have expanded more on what this could mean for our ecosystem and the reproductive possibilities of invertebrates. She also could have included more background on the other two cases of this type of reproduction.

    I found this review very interesting and I learned a lot about this type of reproduction in invertebrates. This will change my understanding of how some animals produce without males.

    ReplyDelete
  7. AP Biology George Daskalakis
    Current Event 16 2/7/16
    Cummins, Anna. "Zebra Shark Surprises Scientists by Giving Birth without Male." CNN. Cable
    News Network, 17 Jan. 2017. Web.
    http://www.cnn.com/2017/01/17/health/zebra-shark-reproduction/index.html
    Evelyn did a great job while reviewing the article “Zebra Shark Surprises Scientists by Giving Birth without Male” by Anna Cummins. The first thing Evelyn did exceptionally well was finding an interesting article that pertains to a field of biology that we just studied. This was great because the topic is fresh in my mind so the article was easy to comprehend. Second, Evelyn had a great throughout summary of the article. This summary made the topic at hand crystal clear and even more easy to understand. This was important because now the review is seamless. Lastly, Evelyn was able to include the string overall tone that was in the articles in her review which allowed for the review to be convincing as well. All of these aspects of Evelyn’s review made for a great piece and allowed the reader to understand the topic at hand.
    Even though Evelyn excelled in parts of her review, there are still some parts that were not so good and could use some improvements. For instance, Evelyn could have given a more in-depth review of the process of this asexual reproduction. Her description and review of the concept was slightly vague and left the reader with many questions that could not be answered by reading her review. In addition, I think Evelyn could have added an in depth analysis of what this discovery contributes to the scientific community and what the researchers are going to do next with their newfound research. This addition would have been beneficial because it allows the reader to see what the scientists’ plans are and will allow the reader to engage in even further research.
    Overall, I found both the article and the review to be very well written and was very informative as well. I was able to learn more about asexual reproduction in animals and some of its benefits it can have on an organism. It was also very interesting to see how even some mammals can take part in asexual reproduction, since I was previously convicted on bacteria and some protists took part in it. The Zebra Shark is definitely an interesting animal to study for many reasons, and will most likely allow people to see what the future of reproduction might look like.

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  8. I read Evelyn’s review of the article, “Zebra Shark Surprises Scientists by Giving Birth without Male” I enjoyed reading her article for three reasons. The first reason is that she provided a very good summary of the article. The second reason is that she quoted the original article which added credibility to her summary. Finally, I enjoyed how she kept her review concise and did not include any useless information.

    Although her review was well written, she could have improved two aspects of her review. The first was that she could have improved on her grammar, as this would have made the review much easier to read. In addition, she should have elaborated on why the evolutionary changes occurred, and how it changed the life of the animal.

    After reading this article, it expanded my knowledge on why animals can reproduce without having an opposite se counterpart, which is quite fascinating.

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  9. In Evelyn’s article review, she did a great job of summarizing the article. I was able to get a general understanding of the main points of the article after reading her first paragraph. In addition, she did a nice job of relating this new reproductive strategy to the environment by stating it could greatly impact population numbers of the endangered zebra shark. She also did a great job of picking an interesting article that relates to what we have recently learned in AP Biology (reproduction).
    On the other hand, Evelyn could have improved her article review. Although she related the article’s importance to the environment well, I think she should’ve also related it to society. This would have made it more relevant for the reader. In addition, Evelyn could have elaborated on her critique of the article more. For example, she didn’t offer any suggestions on how she thought the article could have been written better.
    I chose to review this article because the article’s title drew me in. I became curious as to how zebra sharks could give birth without a male, so I decide to continue reading. Upon further reading, I learned that vertebrates are capable of reproducing without fertilization through evolutionary years of isolation. After reading Evelyn’s review, I have a new found hope that endangered species will be able to grow their populations.

    Cummins, Anna. "Zebra Shark Surprises Scientists by Giving Birth without Male." CNN. Cable
    News Network, 17 Jan. 2017. Web. 06 Feb. 2017.
    .

    ReplyDelete
  10. Cummins, Anna. "Zebra Shark Surprises Scientists by Giving Birth without Male." CNN. Cable News Network, 17 Jan. 2017. Web.
    http://www.cnn.com/2017/01/17/health/zebra-shark-reproduction/index.html


    Evelyn’s review of Zebra Shark Surprises Scientists by Giving Birth without Male was a very interesting review. I liked how she was but in a quote from biologist Christine Dudgeon, explaining the process. This strengthened her review as it helped the readers have a deep understanding of what she is talking about. In addition, the fact that she went further and added other instances when this type of event had happened, added to her review as it was more detailed, which overall aided me in understanding this topic better and gave me some additional, interesting information about it. Finally, the last thing that I thought Evelyn did very well was her second paragraph were she really answered the so what question and was really thorough in explaining why this is important.
    Although this review was extremely interesting, one way it could have been made better is that Evelyn could have been a bit more detailed in her third paragraph as I thought it was a bit short and she could have talked a bit more and elaborated on the why the article was good. So by adding one or two more sentences to that third paragraph, Evelyn could have avoided this problem. Moreover,I would have liked to have a bit more background information about zebra sharks and specifically what they are as I have never heard about them. By just adding one or two more sentences, she could have made her review a bit more detailed.
    Overall, this review was captivating and gave me more details about a reproductive strategy that we had learned about in class but had never went really in depth into it. It is always interesting to be given real life examples about the diverse topics you learn about in class as it helps you understand them better. Moreover, this review also made me realize how much animals are adaptable and how they can make the best out of the environment they are in.

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