Maria Martinez
Animal Life-10:00 am
Dr Clark

"Internal Fight Settles size of Body Parts"

 The second article that was on that I found in the Science News.  I started to choose on the different species presented in different rainforest but after reading this article on the adaptation of different animals acquire in order to survive.  The introduction of the article caught my eye as I was browsing through the pages.  It had the phrase: "survival of the fittest".  After hearing Dr. Clark, our Animal Life professor explains to us the whole process and the explanation of evolution, I thought I'd expand my knowledge.
 This article explains how there is competition for survival in the world.  This not only includes us as human beings but also for animals.  "An unusual new study showing that the absence of one growing organ or tissue allows another to become larger now hints that a similar competition exists internally as animals develop."  For example in one study the front wings of a butterfly are able to grow larger in exchange to the lost of their hind wings, and a beetle can develop larger eyes but lose their characteristic horns.  Which brings up a question of what determines how large these body parts will be and which ones will be lost or reduced.
 Nijhout and colleage Douglas J. Emlen went further in this study.  They approached the issue by working with holometabolous insects.  They discovered that "in their larval stage, these insects stop feeding just before most adults structures form, providing a closed system in which the developing organisms have a finite supply of nutrients and other resources.  By removing the tissues of the hind legs in the caterpillars, the butterflies had larger front wings and small or none at all hind wings.  In the beetles, they added a hormone to stop or reduce the growth of the horns and found that horn did not grow (if so very small), but the beetle did acquire larger eyes, as opposed to the untreated beetle.
 The final result was that Nijhout and Emlen that other body part near the treated part where the ones that were becoming larger.  Nijhout plans to study why the response is localized and whether it stems from reallocating scarce resources.