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Homework Help: Homologous or Analogous Features? HELP!

  1. Nov 8, 2005 #1
    Homologous or Analogous Features?? HELP! PLZ

    Hi I have a mini lab to do where I had to make two charts and compare features of the brown bat, the orca, the koala, the tiger shark, the black capped chickadee and the human.

    In my analysis it says from the first chart which has features such as

    Possessing wings
    feeding on insects
    roosting in trees
    living on land
    eating mostly plant material
    living mostly in water
    possessing structures for swimming
    feeding on fish
    having smooth skin lacking body hair
    lacking earlobes
    having relatively large size

    Which species share the greatest number of features. My answer for this question is that the orca and the tiger shark have 5 similar features and the orca and the penguin also have 5 similar features.

    I am having trouble with the second question it says
    Would you suspect these features to be homologous or analogous? I dont know for sure I am switching back and forth but dont know what to write. The features seem like homologous features but im not sure.

    I have to answer a similar question for the second chart of features but im not sure if this one has homologous or analogous features. The features in this chart used to compare the species are:

    having gills to obtain oxygen
    having lungs to obtain oxygen
    having skeletion comprised of cartilage
    having skeleton comrpised of bone
    being warm-blooded
    having feathers arising from epidermis
    having a four chambered heart
    producing hard-shelled eggs
    giving birth without laying eggs
    producing milk in mammary glands
    having young that develop internally through placenta

    I think in this one the features are analogous, they all seem to have similar function but i dont know if their structures are different or not.

    Can someone please help me im a little confused I know the definition of both analogous and homologous but cant put them with these features PLEASE HELP QUICK!!!!:cry: :cry: :cry: :cry: :cry: :cry: :cry: :cry:
  2. jcsd
  3. Nov 9, 2005 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    Gosh, I wouldn't even be sure on some of those. Typically, homologous and analogous features refer to structural features, not behavioral traits, so feeding behaviors wouldn't be grouped that way, but types of teeth would. Maybe the question is meant for you to determine if each individual feature is homologous or analogous between two species? That's the only way it could make any sense.

    For example, you can look at forelimbs. The bat and the chickadee, both have wings. Are the wings homologous or analogous? What about the flipper of a shark vs the flipper of a whale? And what about the flipper of a whale and the wing of a bird? You should consult your book about the anatomy of these structures in the different classes of vertebrates to determine if it's likely to be homologous or analogous.
  4. Jun 3, 2007 #3
    I need help with this too

    Hi, I have a similar problem wih this lab. I came up with following answer, but it makes no sense when i go to next part.

    a) Orca and tiger shark share all of the characteristics and little brown bat and capped chickadee share all but one feature of general appearance and habits of certain species.

    b) I suspect that these features are analogous, because analogous features are ones which serve the same function in different species but evolved differently or have different anatomical structure. For example, the wing of the chickadee and the wing of the bat are both used for flying, but they have very different anatomical structure, as shown in picture below. A bat wing has metacarpals, five fingers, and thin membrane to cover the wing, while the bird wing has just two fingers, and primary and secondary feathers.

    c) Koala, little brown bat and orca share all characteristics with each other and capped chickadee and penguin both share the same anatomical and physiological features.

    d) I suspect that these features are homologous, because homologous features are characteristics which are shared by related species since they have been inherited from a common ancestor, but don’t have the same functions in modern species.
  5. Jan 7, 2010 #4
    Re: Homologous or Analogous Features?? HELP! PLZ

    I have the same lab :d my teacher said that the first table is homologies and hte second table is anatomical/physiological features :d hope that helps! Good luck!
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