? One always wonder what a single species can do to an entire ecosystem. Gray wolves re-introduction into YellowStone National park has brought the entire ecosystem back to life. Gray wolves are the keystone species of the region. ?

? One always wonder what a single species can do to an entire ecosystem. Gray wolves re-introduction into YellowStone National park has brought the entire ecosystem back to life. Gray wolves are the keystone species of the region. ?