From TNG Homesoil
LUISA: What we're doing is so exciting, so inspiring. We take a lifeless planet and little by little transform it into an M class environment, capable of supporting life. Terraforming makes you feel a little god-like. The first phase involves selecting the planet. That's very important. It must have the right mass and gravity, the correct rate of rotation, and a balanced day and night. The planet must also be without life or the prospect of life developing naturally. The Federation determines if that's so. Then, we take over. This station is phase two. Phase Three involves water. Usually we create basins using hydraulic landscaping, but the water on this planet is subsurface, and extremely high in salt content. We are just about to begin pumping and filtering the water, removing the salt, oxygenating and replacing. Next, we introduce micro-organisms, and when the process is complete eventually, we'll have a lush, arable, biosphere.
(in 30-35 years according to her display)
It's a cleverly veiled comment on abortion.
The life expectancy of the Federation sometimes seems to be measure in months. I'm assuming that these worlds they decline on using or terraforming because they contain life or the potential of life are "inside" Federation borders, and the mighty star empire just goes around these bumpkin worlds, believing the 40 million years after the fall of the Federation, that they could make something of themselves.
After TNG The Chase, could the Federation feel the need to tattoo messages to future species in the future onto their fish and or monkey ancestor DNA as a message in a bottle to explain to tomorrow how the galaxy was so long ago?