Jews is just a a group of humans with certain statistical properties. Science could "exist" without them, no test necessary - they are not a magic ingredient. They did constitute very significant part of Russia's science establishment (despite quotas) and Russia was arguably #2 science producer in math and physics, and this % of their scientists and teachers leaving might plausibly knock them down a few levels. But Russians are certainly plenty smart - Mendeleyev, Kolmogorov, Gamow, etc. etc.
http://www.cbc.ca/news/yourcommunity/2012/07/human-immortality-could-be-possible-by-2045-say-russian-scientists.html
The nice thing about Russians (I'm from that neighborhood originally) is that they are absolutely crazy and will try just about anything. They also probably have/had second-best science culture behind US (though they suffered significant brain drain as huge numbers of educated Jews left in the last 25 years). They have less regulation and quite a few rich people with ideas. Seems like a worthwhile group to keep in touch with.