1. "It's like comparing apples and oranges."

The difference between apples and oranges used to be so stark that to compare them would have been, well, fruitless. But thanks to the triumphs of agriculture and biotechnology, soon we’ll have apples that are oranges. No word yet on whether they’ll keep the doctor away. 

Update: It’s like comparing apples to genetically modified apples.

2. "The early bird gets the worm."