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Are humans (and other vertebrates) most closely related to: insects, mollusks, or...

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elnor | Student, Undergraduate | (Level 1) Honors

Posted March 11, 2013 at 11:49 PM via web

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Are humans (and other vertebrates) most closely related to: insects, mollusks, or echinoderms?  Explain your answer in relation to life history characteristics.

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jerichorayel | College Teacher | (Level 1) Senior Educator

Posted March 12, 2013 at 3:36 AM (Answer #1)

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Humans are classified as vertebrate which means that they have a true skeleton and a backbone. However some animals in other phylum seem to possess that characteristic though not really to the full extent. Insects, mollusks and echinoderms are all invertebrates.  Among the invertebrate, the closest phylum are the echinoderms. Here are some reasons why echinoderms are the closest animal related to humans:

During at larval stage, echinoderms have notochord which apparently disappears as they grow to a mature animal. They also have throat openings (pharyngeal gill slits); nerve cells; and a muscular tail that extends past the anus. 

Recently, genomic sequences have shown that sea urchins (an echinoderm) prose many similarities with vertebrates. 

 

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