I went through a lot of versions of this joke. In the original, they were formulating a comic strip, with the punchline blank. Also, it was clear what they were trying to work out from the first panel. But I figured the whole thing was a little too meta and kinda hard to figure out. So I switched to a “How many x does it take to screw in a lightbulb.”
But then halfway through drawing, I figured a ‘Yo mama’ joke would be funnier for scientists to contemplate. And so here we are.