What began as a war of hearts and minds slowly evolved into a war of extermination.

As the Western birthrate dropped, the manpower crisis became increasingly acute.  Robots relieved some of this problem, but many dangerous jobs required a level of creativity and planning a positronic brain could not match.  The biological revolution offered a solution:  androids.  Androids appeared to be human, but were genetically engineered from scratch to a set of specifications.  Androids were living, thinking, sentient beings, often times bionically enhanced to fulfill their duties.

This eventually led to ethical problems.  Slavery had been abolished in the Western World for more than two centuries, and while androids were not human, they were more than simply domestic animals.  After a number of minor android revolts, a compromise was reached.  Androids would serve a set period of years for the person or corporation that commissioned their creation.  Afterward, they would be considered free beings.

Most androids were incapable of reproduction (some few were designed for it on an experimental basis).  Androids were designed, grown and modified in large biotechnical facilities.  After the limited emancipation acts, many of these facilities were built and controlled by free androids.

The Biological Revolution

Cloning was first demonstrated in the late 20th century and continued to be perfected in the following decades.  At first, it was used to reproduce disease-resistant crops and superior lines of domestic animals.  These efforts expanded to the commercial cloning of beloved pets and to recently extinct animals.  Zoos and wild-animal parks began to introduce and display even more ancient extinct animals on the justification that since man had had a hand in their initial demise, he was responsible for resurrecting them.  Early "Pleistocene Parks" sported mammoths, mastodons, giant ground sloths, glyptodonts and dozens of other species for which genetic material could readily be found.

As genetic engineering techniques became more refined and more organisms' genomes were mapped, researchers were able to extrapolate and reconstruct the genomes of more ancient animals and plants.  By mid-century dinosaurs (or at least reasonable facsimiles thereof)  roamed wild-animal and game parks. 

The biological revolution allowed geneticists to not only recreate the organisms of the past, but to design wholly new creatures.  Mythological beings such as dragons and unicorns leaped from the pages of story books to the enclosures in zoos and amusement parks.

Darker things were also built by the geneticists -- creatures that were unleashed upon the enemy to frighten and demoralize him.