Two butterfly species have been bred in the lab to make a third distinct species, the journal Nature reports. In a species, individuals need to be capable of interbreeding to produce fertile offspring. The study demonstrates that two animal species can evolve to form one, instead of the more common scenario where one species diverges to form two. The process has been likened to building a new bike from a pair of second-hand ones. The Heliconius heurippa butterfly appears to be the product of a process called hybrid speciation. Most species are thought to form when groups of organisms gradually...