Answer:
<em>Open </em><em>circulatory </em><em>system</em><em> </em><em>is </em><em>the </em><em>system </em><em>that</em><em> </em><em>is </em><em>primarily</em><em> </em><em>found </em><em>in </em><em>invertebrates.</em>
The mode of evolution that is represented by this example is
called coevolution. Coevolution is the process in which two independent species
influence the evolution of each other. This process involves natural selection.
There is nothing working as a forcing agent. Since this orchid named bumblebee
orchid is totally dependent on a single species named bumblebee for its
pollination and this evolution process, so this process is called coevolution. Various
other organisms also follow this method of pollination to continue their cycle
of evolution.
