Most Nobel Laureates in the sciences are highly intelligent, so they exist on that tail.
Basically, if you sample from the top 13% from a normal distribution with (mean, std)=(100,15) you get fewer with 140+ than if you sample from one with (mean, std)=(115,15), and the higher the intelligence, the bigger the difference will be.
This follows from the squaring of the exponential term in the standard distribution.
While it's possible that the shape or standard deviations for various population doesn't match my assumptions, but if they do, the observed number of Nobel prizes given to Jews is very close to what one would expect.