How Did They Get There?  One reason that the animals and plants on Madagascar are so different from those everywhere else in the world is that the island has been isolated for a long time. Today, strong ocean currents sweep between Madagascar and the African continent, keeping animals and plants from moving easily between places. How did animals and plants get to Madagascar, and how are they related to animals and plants in other parts of the world? Scientists have two main theories to answer these questions. DispersalCertain organisms are expert sailors and can float from one place to another on ocean currents. Some things, like ocean-going birds, are well-adapted for long-distance voyages. Others can survive for long periods on rafts, or float around for a long time without food and water. If these organisms arrive in a new place where conditions are right, they may settle down. Over many generations, their offspring may exhibit new characteristics that allow them to better survive in their new environment Mouse over the animals and plants below to see some of their characteristics. Do you think they would be able to make it to an island? Drop them in the water to find out.
Note the characteristics of the organisms
you're putting in the water. Do any patterns emerge? Look at the
additional organisms listed on the field notebook page and predict
whether you think they'd be good at dispersal. Why or why not?
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