Hi, I have a question about insects. 
If you breed them in an enclosed area that where you increase the oxygen level to that equal to the Carboniferous period will you get giant insects? Or will they just grow normal size.

IIRC some studies have been done on this (though irritatingly I can't remember the references).  If I recall correctly, there was a statistically significant difference in size: the insects grown in the oxygen-rich environment did grow somewhat larger -- though nothing that you'd call "giant" at all.  Certainly insect raised in an oxygen-poor environment come out smaller.

But whatever growth you might get from raising a given generation of insects in an oxygen-rich environment is insignificant compared with the evolutionary effect of such an environment over time.  When more oxygen is available, larger insects are more suited to the environment and will tend to survive and breed more successfully than smaller ones, so the big-insect genes will get passed on leading to a larger-sized population.

That's the theory, anyway.  I don't know if that experiment has been done, but given the short life-cycles of insects, it would be surprising if it hadn't.  Does anyone out there know more?

(If it's NOT been done, Niels, then maybe you could do it?  It would be a genuine contribution to science.)