Where did the cracking start? Around commode? Something is rotted?
What do you mean by "wavy" - the edges aren't cut straight or they are
buckled/warped?

It started mostly in the center of the room. All the wood seems to be in
very good condition. I don't see any sign of moisture damage. Last week
my 2 year old daughter dumped a pitcher of water from the tub onto the
floor so there is a stain there, but everything is solid certainly no
sign of long term water exposure. If you put a straight edge across the
boards there might be about 1/16" spaces all around.

Thanks
Dante