Thursday, April 25, 2013

Analogous trait


1.       Both Butterflies and Humming birds are species that can fly, but they’ve also developed a long tongue used for extracting nectar from flowers.

Humming birds possess a beak and tongue long and narrow to be able to extract nectar from the flowers in their habitat, for example, the Sicklebills' extremely decurved bills are adapted to extracting nectar from the curved corollas of flowers in the family Gesneriaceae. While the butterfly uses a straw like proboscis that curls when not in use. When the fly emerges from as a butterfly it is actually in two pieces the zipper together.


 
1.       While both humming birds and the Honey possum possess a long tongue used for drinking nectar, they are extremely different species. Both tongues are held within elongated hard structures, however one is a snout that also contains the nostrils, the other is a beak with no other functions.
The closest these two species have, one being a marsupial and the other a bird, would be at a time when the first animals took flight.

1 comment:

  1. I'm not clear as to which pairing is meant to be homologous and which is analogous, but in this case, both pairings are analogous.

    Analogous traits do not share a common genetic origin but share similar structures due to common functions and environmental pressures. This describes both of your pairings.

    Homologous traits would share a common genetic ancestry but would have different structures due to different environmental pressures causing different functions to be advantageous. An example of this would be the forelimb structure of the hummingbird and the honey possum. The basic structure was inherited from a common reptilian ancestor but the need for different functions (flying vs. grasping/climbing) has resulted in differing structures, in spite of the genetic commonalities.

    Make sure you get an opportunity to review these concepts before the midterm and let me know if you have any questions.

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