The story happens between two different planets. The first is basically a futuristic-different-reality Earth, and the second is a planet that is constantly on the exact orbit as Earth except for every few years when half of the planet turns desert, and the other half arctic cold. In this different reality, there is an extremely recessive gene that humans have that gives them a second 'form', but unbeknownst to the scientists of the time, there is an even rarer gene that allows that person to have multiple 'forms'. These forms are all animal forms. Each form depends on one or more characteristic of that person.
Here is a few examples of how this works. One of the characters is Yvette; she was born on earth blind. Her parents agree to try to fix it via eye surgery, and she can now see light and dark. Because she was blind born blind, her form is a bat. But a side effect of the surgery that allows her to see light and dark is that her hair is permanently white. So her form is now a white bat. Another character, Alondra has a problem with talking, and so everyone at first sort of ignored her when she was little. But she loved dancing and graceful movement, her form is a swan.
I have started a Pinterest board for this series (There is no way I can make this into one book without leaving out some character's story. . .). http://pinterest.com/thewayislife/black-wing-series/
As an end note, I am thinking of calling it the Black Wing Series because one of the constant main characters is nick named for her favorite form as a raven.
Sole Deo Gloria,