Jeez here the term DNA refer to the whole ecosystem of the planet. It basically means Terraformation.
* It will now be several centuries since the colonization of space was made possible. Thanks to the terraforming process, humanity is now able to change and model the DNA of the planets, which makes its expansion all the easier. But this development came at a price and many wars followed for the control of these new lands. At that time it was believed that nothing could stop them. That humans would never learn .... At least until their appearance *.