And even after transportation and travel developed, what types of people from what regions have large populations of what blood types?
A, B, O, AB, – these can be either – or +. these are the only blood types. they have always exsisted like this and we are just recently learning about this as well as antibodies in the blood. other than that, I don't understand your question.
What we call "blood types" are actually proteins that are present (or not) on the outside of our red blood cells. you are probably familiar with what we call the ABO system (the first one that science identified) and may have heard of the Rh system (that is the + or -) but there are more than a dozen others commonly tested for.
The simplest system to explain to you is the ABO system. That involves two specific proteins that may or may not appear on the outside of your red blood cells. One is called "A" and the other is called "B." If you have just protein a, then you have blood type a. If you have just protein B, then you have blood type B. If you have both proteins then you have blood type AB and if you have neither protein then you are blood type O.
Like all of the rest of the various blood groups, a, B & O are present in virtually all populations to some extent, though some ethnic groups might have a higher preponderance of one than another. Neither I nor anyone else can answer your questions about the ancient history of blood types or what effect transportation has had. they are a modern discovery, first becoming known about the time of WWII.
One very interesting – and extremely rare – bloodtype phenomenon was first associated with a location, however. That is called Bombay O – first discovered in a man from Bombay. Those who have Bombay O are lacking the protein in the outer membrane of the red blood cells that the bloodtype protein attaches to, so that they appear to be Type O but are actually not.