What's the History?

On average, around three-quarters of the Kenyan national cross country team each year hail from the Rift Valley Province (Tanser).  The Rift Valley Province has a long history of producing outstanding long-distance runners, likely because here resides the Kalenjin tribe.  Sometimes referred to as Kenya's running tribe, the Kalenjin only make up about 12% of the population of Kenya, but make up most of the national team ("Kenya").  So I realize now that when I'm describing all of the possible reasons for Kenyan success, I looked over the fact that the country itself is probably so good at running because of the Rift Valley.  So the real question is, how did this one little part of Africa become the so called long distance running capital of the world?
Researchers such as Mike Lambert, of the Sports Science Institute of South Africa think that the Kalenjin may have a genetic predisposition to distance running due to a very long history of being good at the sport (Noble). There are many different ideas as to why this theory makes sense, mostly based on the reasons for
evolution :

• Natural Selection :  the Kalenjin were historically pastoral people, and their method of herding was running alongside their cattle, so some say that over time, maybe they evolved to be better at distance running because the herders that were good at running were more successful (Noble).
• Mutations : in any group of people, there will be genetic mutations, and in an isolated community such as the one in which the Kalenjin originated, these mutations could spread throughout the whole population.  Perhaps the ability to run long distances so well was a mutation that stayed in the population after generations and generations (Fisher).

The main argument against these ideas is that no one has ever found a specific gene that relates to distance running (Fisher).  But a few very interesting studies have been done relating to this topic.  In 1990, the Copenhagen Muscle Research Center compared boys on the high school track team in Iten, Kenya to Sweden's national track team.  The Kenyan boys consistently ran better than the Swedish athletes who ran professionally.  From this, it was estimated that the average Kalenjin could run better than 90% of the world population.  In 2000, a study was done by the Danish Sports Science Institute in which they gave a group of Kalenjin boys three months of training, and then compared them to a Danish track champion.  With only three months of athletic training under their belt, the schoolboys beat him (Fisher).  How does this happen?
Once again, it has never been proven that there is a specific gene that causes an aptitude for distance running.  But on the other hand, Mike Lambert found in a study that 72% of the boys at the Nandi (subtribe of the Kalenjin) school St. Patrick's High (in Eldoret) that were good runners were related to elite athletes (Noble). There are many other factors other than genes that could effect this as well such as each specific family's culture or traditions, but I don't think that the gene theory can be ruled out completely by lack of evidence.  It may not have been proven scientifically, but it definitely has some grounds to stand on.
As a disclaimer, I want to clarify that I am talking specifically of the Kalenjin tribe in this post, and not of all of Africa.  There are some researchers who claim that there is a so called 'black speed gene', and that is the only reason why runners of African origin are so talented.  This is not at all what I am trying to show in this post, or on this blog in general.