I heard theory, that we didn't really changed since 200 000 years.
That is if you brought newborn from 200 000 years ago he would live here just fine.
Wrong theory. Evolution never stops. Mutations are going constantly.
First of all, a newborn from 200000 ago would look "funny", and that's would make his assimilation difficult. But most importantly, brain has undergone huge changes. Most probably this person would be considered ret-ar_ded by modern people.
On the other hand, people from 16 century could have been smarter, than modern people. This is based on studies conducted by some 16 century scientist. He made a machine which measured reaction time of people. And he recorded results.
In modern times, two scientists of Russian origin have built the same machine. Using instructions made by 16 century scientist. Funny, but that machine gave more precise measurements of reaction time. Because modern computers add several milliseconds to measured result because of all sorts of lags existing in the computer system.
So what the modern scientists found, is that reaction time of 16 century people were slightly better, than of modern people. And that with same measuring instrument.
It means that they probably had higher IQ. Because reaction time has very high correlation with general ability of brain (G-factor, which can be measured by IQ tests).
You can easily check it by trying to be beat Chinese guy in table tennis, for example. Average IQ of Chinese people is 106, while white Europeans have 100.