"While reading this, I was wondering if you couldn't equate Sauron with a mad scientist with all the gene splicing to create his orks and Brukhi (I know, I spelled it wrong, but I didn't want to get up to get the book). There have been other fantasy novels also that the evil wizard practiced a form of organic or genetic fusing to create the creatures that did their nefarious bidding. Cave weights, Kabold, Dark Elves, gnomes."Genetics, if anyone remembers science class, was first codified by the monk Gregor Mendel in the mid-19th Century while experimenting on inherited traits in pea plants. However, people have been cross-breeding plants and pets (dog breeds are an example) since ancient times. Classical Sparta practiced selective breeding in its citizens -- look at the movie 300 for an object example. In the opening scenes, we see an elder of Sparta investigating a baby to see if he passes muster for inclusion into Spartan society. If he did not, then the child could've expected instant death.
Simple genetics thus deals with traits inherited from two "parents," whether human, animal, or plant. In this manner, wizards like Sauron and Saruman in the Lord of the Rings trilogy can be considered mad scientists because they blend Orcs and Goblins into the new Uruk-hai, a race of creatures that can move in the sun like Orcs but have the strength of Goblins. This simple usage of inherited traits falls under the general umbrella of genetics.
With steampunk, genetic manipulation takes on a more contemporary feel. In Scott Westerfeld's Leviathan, for example, we see the British Army using fabricated animals crafted after Charles Darwin's discovery of DNA and genetics. Truth be told this is actually an expansion on what we know about DNA manipulation -- modern science only allows for very simple organisms to be built, not anywhere near on the scale of the whale airships in that novel.
A simple search of "genetics in fiction" brings up a list of books both at Barnes&Noble and Amazon, but much more in the future/near-future science fiction realm than in steampunk or in standard fantasy. Of course, this could also be tied to people not always considering certain things as genetic science rather than "magic" as in fantasy.
Genetics offers such opportunity for authorial hand-waving or even honest-to-goodness fictional science, that I'm slightly surprised it hasn't quite been done to death in modern fiction. Then again, it might have been without me noticing (which is entirely possible).
But I'm curious: what other novels, films, or video games can you think of that deal in genetics as a plot point? And do you think genetic manipulation and its consequences has been overdone in storytelling?