Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[Q]: Pangaea began breaking apart 250 million years ago.
[A]: How many millions of years ago did pangaea begin breaking apart?


[Q]: While the numerical aperture can be used to compare resolutions of various objectives, it does not indicate how far the lens could be from the specimen.
[A]: While the numerical aperture can be used to compare resolutions of various objectives, it does not indicate how far the lens could be from the what?


[Q]: Adult humans lack some of the defining traits of chordates.
[A]:
Who lack some of the defining traits of chordates?