There is No Definition of "Species"

There is no authoritative definition of “species.” The most widely accepted definition describes a group of organisms that can procreate with one another and produce fertile offspring, but there are many exceptions. De-extinction operates under a different definition altogether. Revive & Restore hopes to create a bird that interacts with its ecosystem as the passenger pigeon did. If the new bird fills the same ecological niche, it will be successful; if not, back to the petri dish. �...