Two questions...

Did anybody know about the gene Sonic Hedgehog? It's meant to keep other genes in check. No, I'm no making this up. The picture above is from by 9th grade Bio Hon textbook. So, how many people knew this?

And...

SEGA has always proclaimed that Sonic can (but doesn't always) run at the speed of sound. But that's all they say regarding his speed. They don't say he has a speed limit. So, my question is: does Sonic have a speed limit?