People---one thousand years ago ---were not biologically DIFFERENT in any reasonbly detectable way to people now. The person who made that claim does not understand human physiology, genetics or "evolution" In fact people world wide -----are essentially the same biologically---that is PHYSIOLOGICALLY overall ------there are very very minor differences in gene pools An interesting factoid is that BRAINS are all -----overall in large groups ----virtually the same as to potential capacity for FUNCTION
Clearly you don't know about the environment effect to human biology. So please do more research.
A small example, the plague by itself changed the biology of whole europe back in the days.
More reading for you...
your statement is IDIOTIC the plague changed nothing there are some theories that some people who SURVIVED the plague did so because they were able ---based on their physiology, to withstand the specific bacerium YERSINNIA PESTIS ----thus more people who could not withstand Yersinnia pestis died than did those who could----that fact does not come close to CHANGING HUMAN BIOLOGY in any significant way
there are a lot more examples of population adaptation than that little one For example----in areas with lots of MALARIA there are more cases of HEMOGLOBINOPATHIES like THALASSEMIA than in places with less malaria-----because the bug needs healthy red blood cells for survival ------but no one in his right mind would describe that fact as PEOPLE ARE NOT THE SAME over there in the area of the MEDITERRNEAN------basically they are about the same as people from New Jersey. Stop playing with ideas that confuse you