This question has come to me before but I never got around to finding out the answer. Although I'm pretty sure of it.
When you trade techs, will you lose the inherent bonuses on techs that get skipped? That is, if i get warp 2 and skip warp, will I lose that +10 to speed that warp gives? Same as for and techs with built in bonuses.
It occurred to me that since the AI probably doesn't go backward on the tech tree you could trade it for a better tech but hurt it by removing those bonuses. So you get more for the trade and the AI actually loses something.