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Biology LibreTexts

2: Comparative Vertebrate Anatomy Observations

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  • In this lab, you will consider the morphological processes of evolution and development by examining developing vertebrate embryos.

    Before you start please adjust your oculars so you can see two full circles, you may need to slightly adjust how far your eyes are from the microscope.. This can take 5-10 minutes so be patient.

    Please choose one of the following:

    1. Chick or Frog embryo, single stage (you will “reconstruct” the 3D morphology by comparing sections of a single embryo).

    2. Chick or Frog embryo across time (you will “reconstruct” development by examining different stages)

    3. Chick and Frog comparisons (you will compare Chick and Frog morphology at a similar developmental timepoint)

    Take some time to get acquainted with your slides and your microscope. Make sure you can see through both oculars and you are focusing up and down for each section.

    Start to make a few sketches of what you see on plain white paper. Practice drawing the features that stand out to you and seem salient. You may use the books provided, online resources, or people in the classroom for help in figuring out different features.

    Note: I offer an extra credit for an art piece based on sketches (examples below) and provide watercolors, watercolor paper, and colored pencils for the students. I grade it on detail, quality, and overall aesthetics.


    Early Frog Development

    Late Frog Development

    Chick Development

    Sections of a chick embryo at five stages by Kristina Vu


    Frog vs. Chick comparative embryology during late-organogenesis by Yongjin Byun