Friday, May 23, 2014

New Theory on How Flightless Birds Spread Across the World

Current Event #2                                                                                Mallory Bates

Zimmer, Carl. "A Theory on How Flightless Birds Spread Across the World: They Flew There." The New York Times. The New York Times, 22 May 2014. Web. 22 May 2014. <http://www.nytimes.com/2014/05/23/science/a-theory-on-how-flightless-birds-spread-across-the-world-they-flew-there.html?ref=science&_r=0>

I read an article called “A Theory on How Flightless Birds Spread Across the World: They Flew There.” It discusses the elephant bird, an extinct, huge, flightless bird whose fossils have been found in Madagascar. Recently, DNA was extracted from these fossils and scientists discovered that the elephant bird’s closest relative is the kiwi, a tiny flightless bird found about 7,000 miles away in New Zealand. This new evidence fuels the debate on how flightless birds ended up all over the Southern Hemisphere. Previously, it was believed that the supercontinent of Gondwanaland allowed for ratites to walk to where they have been found by scientists. However, when they estimated when the two birds shared a common ancestor, scientists found out that the ancestral bird lived about 50 million years ago, which complicates the Gondwanaland-theory because by then, Madagascar and New Zealand were already separated by a vast ocean. Without flying, the migration of this bird would have been impossible. A new theory has been proposed, saying that this not completely flightless ancestral bird flew across the world to New Zealand, where it remained and developed into the common kiwi bird we know today.
This new information is extremely relevant to our world and especially our Earth Science class. We recently studied evidence for the Plate Tectonic Theory, and one of the examples was the fact that a certain plant species was found in corresponding parts of Africa and South America, proving that they were once joined. This ties into that because people just assumed the same thing happened with ratite birds, but this new information totally changes that, even if it is just a theory. Science is always changing when new discoveries are made, and this proves that sentiment.
I thought this article was pretty well-written and informative, except for the fact that it was hard to follow sometimes. I had to keep going back to remind myself what the author was talking about, but other than that, it was a thorough yet concise piece of writing. I had no idea about the extinct species of the elephant bird, let alone the idea of a new theory coming from the connection of this ancient species to the present day kiwi.   



1 comment:

  1. Michelle Paulson’s Current Event Comment for Mallory Bates
    This review does an excellent job presenting the key points of this article and establishes the main controversy (the fact that two flightless birds 8,000 miles away, even during when the elephant bird came into existence), using the key points and solid facts in order to highlight the issue. Secondly, the importance of this article to today was well-established, and a conscious effort was made to tie in the significance of the discovery of the kiwi bird’s and the elephant’s bird ancestral history with science overall. Last but not least, the article and both its strengths and weaknesses were evaluated effectively.
    This review and its article’s ability to catch one’s interest were so great that it became the sole basis upon which this comment was written. One of the most intriguing matters at hand was the existence of the elephant bird. Even though it had existed fifty million years ago, it also has been rumored to exist even during the nineteenth century. Despite the primary sources pointing to its survival in the age of humans, the reason for its extinction is still shrouded in mystery. On the other hand, it is most impressive how well the writer of this current event maps out a connection between the earth science class she is in to this shocking but not so hard-to-believe New York Times article because of a theory that a bird with flight became the ancestors of two ratites thousands of miles away.
    Although this review was exceptionally well written and did a good job in summarizing the article and providing its relevance, more detail could be put in the analysis, and instead of connecting specifically with the classroom, more emphasis could be placed in a global context.

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