One group of scientists, called project Tauros, is trying to bring back the aurochs. They are trying to create a living replica of an aurochs by mixing genes from aurochs teeth and cattle relatives. The aurochs was a creature of tremendous strength and size. As is shown by the over growth of the beech tree upon the aurochs extinction, the loss of the aurochs is another example of the fact that every plant and animal in the environment, from beetles to bears, depends on each other and needs to be saved in order for a healthy ecosystem to thrive. My hope is that project Tauros will work and enable more organizations to help bring back other extinct animals.
Sources: National Geographic July 2010, Project Tauros