How Can I Survive Without You?
Over time organisms have developed structures that help them to survive in their environments. Organisms with traits that help them survive are the ones that will live long enough to reproduce and pass these favorable traits to their offspring.
While a trait may allow an organism to survive in one area, it may not survive in a different environment. Traits that are useful are passed from parent organisms to their offspring.
Look
closely at a reason why birds are able to fly. Unlike you and me, bird bones
are hollow. You know that with less material in the same area, there is
a lower density. This lowere density in a bird's bones provide something
which allows them the ability to fly. As you look at the bird bones at the
right, you should notice that you can actually see the holes in each of
the bones. Truly hollow bones would break easily, therefore there is still
some material inside each bird bone. Watch the QuickTime video below to
see an example of a bird flying.
Look closely at the video of the bird flying above. If you need to, press the "Play" arrow and watch it more than once!
Remember that most birds need to fly to survive. Having less dense bones is an advantage as this trait makes the bird much lighter. To understand why being lighter is an advantage, imagine running a race wearing a 50 pound backpack verses running the race without all the extra weight. Flying, for birds, is like running the race, for humans, having less dense bones is like removing the backpack.
Fish have fins
Fish, unlike birds, do not need to be able to fly in the air. They, however must have fins that allow them to move easily through the water. Fins are an advantage to fish, because fins help fish move around easily in their watery homes. It’s kind of like putting on flippers when you swim. The flippers help you move faster through the water.
To observe the fish fins, you must look closely at the fish in the beaker in the movie above. The fins are moving slowly at the sides of the fish.
Analysis:
- How would the hair on a bear help it to survive?
- What characteristics does a lizard have which help it survive in a
desert?
- What specific traits does a mule deer have which allows it to survive
in Utah?
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Get the plug-ins: Want to share a photograph of you or your friends doing this activity? Send the photograph attached to an e-mail with the following information: the title of the activity, the URL (Internet address), and your name. Remember that no pictures can be used which show any student faces or has a student name on it. Updated August 11, 2005 by: Glen
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