Jake Paul fought a 47 year old Anderson Silva last year in an 8 round boxing match. It was 5-3 in favor of Jake with a KD. 47 is very old but he still managed to give him his 2nd toughest fight. He did better than the other MMA guys jake fought like Tyron Woodley, Nate Diaz, and Ben Askren. This makes me wonder what the outcome would have been had the clock been turned 10 years back but only for Silva. Basically a current Jake vs 37 year old anderson silva. All the other MMA guys he fought were near 37 (woodley and diaz both 38 and askren was 36 at the time they fought).
Anderson gave a pretty good account of himself at 47 with a decade of losses behind him. I think the 37 year old version would have had enough athleticism left to win, probably by stoppage.