The Pirates of Ersatz by Murray Leinster

According to the fiction tapes, the colonized worlds of the galaxy vary wildly from each other. In cold and unromantic fact, it isn't so. Space travel is too cheap and sol-type solar systems too numerous to justify the settlement of hostile worlds. There's no point in trying to live where one has to put on special equipment every time he goes outdoors. There's no reason to settle on a world where one can't grow the kind of vegetation one's ancestors adapted themselves to some tens of thousands of generations ago. It simply doesn't make sense!

So the inhabited worlds of the galaxy are farther apart than they could be, perhaps, and much more alike than is necessary. But the human race has a predilection for gravity fields not too far from 980cm-sec accellerative force. We humans were designed for something like that. We prefer foodstuffs containing familiar amino compounds. Our metabolism was designed around them. And since our geneticists have learned how to put aggressiveness into the genes of terrestrial-origin plants -- why nowadays they briskly overwhelm the native flora wherever they are introduced. And it's rational to let it happen. If people are to thrive and multiply on new worlds as they are colonized, it's more convenient to modify the worlds to fit the colonists than the colonists to fit the worlds.