How will the planet end?

[Aoi Magi]

I can't quite remember the name but I read a good sci-fi book recently which is about a ship full of humans trying to survive in space but to go anywhere they have to stay and breed in space for a few generations, however without the earth's diverse ecosystem, it doesn't go too well and each successive generation gets physically and mentally weaker.

Was it the novelization of Wall-E?

It's more like a cross between Wall-E and The Hundred. It's quite interesting to read though because it deals with what we could actually do with our current technologies.