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  <name>What is a species?</name>
  <metadata>
  <md:version>1.2</md:version>
  <md:created>2004/11/18 12:53:04 US/Central</md:created>
  <md:revised>2006/01/21 00:28:30.120 US/Central</md:revised>
  <md:authorlist>
      <md:author id="alisonfromme">
      <md:firstname>Alison</md:firstname>
      
      <md:surname>Fromme</md:surname>
      <md:email>alisonfromme@nasw.org</md:email>
    </md:author>
  </md:authorlist>

  <md:maintainerlist>
    <md:maintainer id="alisonfromme">
      <md:firstname>Alison</md:firstname>
      
      <md:surname>Fromme</md:surname>
      <md:email>alisonfromme@nasw.org</md:email>
    </md:maintainer>
  </md:maintainerlist>
  
  <md:keywordlist>
    <md:keyword>biology</md:keyword>
    <md:keyword>history of science</md:keyword>
    <md:keyword>species</md:keyword>
  </md:keywordlist>

  <md:abstract>What is a species?  In the past, scientists classified living things into categories based primarily on morphological characteristics, such as beak size, tail length, and coat patterning.  Today, scientists use several methods, including genetic analyses, as described below.</md:abstract>
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  <content>

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	  <param name="width" value="100%"/>

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<section id="recent_research">
<name>Recent Research</name>
<para id="research1">
Scientists are refining their taxonomic strategies in the hope of developing a standardized method of classifying, identifying, and describing the evolutionary history of species.  The following links will take you to original research addressing these issues.  <list id="research2">

<item><link src="http://www.plosbiology.org/plosonline/?request=get-document&amp;doi=10.1371%2Fjournal.pbio.0020312">DNA Barcodes and Bird Identification, <emphasis>PLoS Biology</emphasis></link></item>

<item><link src="http://www.pnas.org/cgi/content/full/101/41/14812?maxtoshow=&amp;HITS=10&amp;hits=10&amp;RESULTFORMAT=&amp;fulltext=DNA+Barcode&amp;searchid=1107543176414_5552&amp;stored_search=&amp;FIRSTINDEX=0&amp;journalcode=pnas">DNA Barcodes and New Butterfly Species, <emphasis>PNAS</emphasis></link></item>

<item><link src="http://www.plosbiology.org/plosonline/?request=get-document&amp;doi=10.1371%2Fjournal.pbio.0030009">New Zealand's Extinct Giant Eagle, <emphasis>PLoS Biology</emphasis></link></item>

<item><link src="http://www.plosbiology.org/plosonline/?request=get-document&amp;doi=10.1371%2Fjournal.pbio.0020442">New Tiger Subspecies, <emphasis>PLoS Biology</emphasis></link></item>

<item><link src="http://www.plosbiology.org/plosonline/?request=get-document&amp;doi=10.1371%2Fjournal.pbio.0000006">Conservation of Asian Elephants, <emphasis>PLoS Biology</emphasis></link></item>
</list>
</para>


</section>
<section id="Species">
      <name>How do scientists identify and name species?</name>
      <para id="Species1">
<term>What is a species?</term>
	Scientists don't agree on the exact definition of a species. 
Read about <link src="http://evolution.berkeley.edu/evosite/evo101/VADefiningSpecies.shtml">
species concepts</link> on this UC Berkeley site.
      </para>

<para id="Taxonomy1"> <term>What is taxonomy?</term>  Taxonomists name and classify living things, so they play an important role in determining how we define species.  Read more about <link src="http://www.visionlearning.com/library/module_viewer.php?mid=70">taxonomy</link> at this Vision Learning website.
</para>    

    <para id="linneaus1">
      <term>Who was Linnaeus?</term>  Read about the taxonomist <link src="http://www.ucmp.berkeley.edu/history/linnaeus.html">Linnaeus</link> on this UC Berkeley site.
    </para>   

<para id="Classify1">
<note type="PBS NOVA Interactive">
    Try your hand at classifying living things using <link src="http://www.pbs.org/wgbh/nova/orchid/classifying.html">Linnaeus's method</link>.
</note>
</para>   

<para id="currentclassification">
<term>What are the current approaches to classification?</term>  Scientists today use morhological (physical) traits, embryology (patterns of development), and molecular biology to identify species.
<note type="PBS Interactive">
Classify organisms using <link src="http://www.pbs.org/wgbh/evolution/change/family/index.html">current methods</link> in this activity.
</note>

</para>

<para id="museum">
<term>Can't get to a museum?</term> Visit the Zoological Museum Amsterdam in the Netherlands online and check out hundreds of <link src="http://ip30.eti.uva.nl/zma3d/">3-D bird specimens</link> online.
</para>


</section>



<section id="yourturn">
<name>Your turn...</name>
<para id="question1">
<list id="discussion">
<item>Why is the naming and classifying of species so difficult?</item>
<item>What are the advantages and disadvantages of different methods?</item>
<item>If you could create your own classification system, what factors would you consider?</item>
</list>

</para>
<para id="detail">  <term> Digging Deeper:</term>  Want more detail about how classification, taxonomy, and evolution are related?  <link src="http://www.ncbi.nlm.nih.gov/About/primer/phylo.html">The National Center for Biotechnology Information</link> provides a very thorough explanation.
</para>

</section>

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