high IQ of Ashkenazi Jews + persecuted past - a link?

[Big Papa Goat]

It wouldn't be exactly right to compare sailors to the African slaves regarding selection for hypertension, since sailors aren't really a population in the same way the slaves would have been. A sailor that has hypertension or whatever to survive at sea would live longer than another sailor, but that sailor will just go and have offspring that may inherit his hypertension genes but will not neccesarily be sailors dig? What I mean is that the next generation of sailors won't neccesarily be the offspring of the last generation of sailors who possessed genes for survivng at sea.
Basically the point is that for natural selection to work on a group, it has to be a biological populaiton, meaning an essentially reproductively isolated group. Since sailors aren't reproductively isolated, they can't evolve common characteristics.

Slaves with genes for survivng at sea would have had greater survival rates on the way to America, and this would have caused something of a founder effect. The population of slaves that arrived in America would have had a greater proportion of individuals with the genes that aided in surviving the trip over, and this could have theoretically lasted, since slaves in America were essentially reproductively isolated group for at least a couple generations.

There may not be 'races' of the human species, and indeed, there are no significant differences between different populations of humans, but that doesn't mean that certain traits can't be selected for in human populations given the right selection pressures. An entire population being transported across the Atlantic in such a brutal fashion could certainly have put the kind of pressure on a population to significantly select for a paticular trait.
Epidemics of diseases are a good example of pressures that rapidly cause selection for paticular traits. Within the space of a few generations, a population that was once almost completly vulnerable to a disease like smallpox or the plague can become almost entirely resistant to it.
Again though, such rapid selection pressures are limited to a few circumstances, and only cause paticular genes to be selected for. The "races" of the world may have had different selection pressures for a few things since they seperated, but human populations haven't really been seperated for long enough to diverge in any really significant ways.