This is a complicated issue, and I think you are confusing things a bit. Of course, for a gene to take an effect (produce a protein) it has to be activated via a certain chain of chemical reactions that is triggered by environmental conditions. So, sure, genes give widely different results depending on the environment of the organism. In professional competitive sports however we have a large group of people that undergo really similar stimulus. They all train the same discipline, follow similar training regimes, eat really well etc. To think that in such situation genes do not play a huge role is I think naive in the light of what we know about biology. I also don't see what your examples have to do with it, really.

By the way, I find it a bit silly that those articles about genetic differences concentrate on sports so much. Somehow it is much easier for people to swallow that our bodies are shaped by our genes, that it is to accept that a large part of our mental makeup is as well, despite strong scientific evidence for it. For the same reason I think any notion of "fairness" in this context meaningless, genes make every one of us who we are and we have vastly different capabilities concerning all activities, from chess playing, through math problem solving, to sports and entrepreneurship. There is no fairness at all in any human activity.

This Atlantic article suggests that you will never win an Olympic medal in sprinting unless you come from West Africa[1]. This same population is bad at distance running, where Kenyans dominate. There appears to be strong genetic components at work here.

[1] http://www.theatlantic.com/entertainment/archive/2013/08/the...

Distance running is the national sport in Kenya. They spend money on it like the US spends money on football. Of course, not to quite the same degree, but the point is still that it is their national sports focus. If Kenyan's are genetically superior at marathons, then Americans are genetically superior at football.

Countries as large as the US, India, China, etc., have large enough populations that someone in them should match the "genetic ideal" to excel at a certain sport. It is economics that prevents them from doing so. Either their country or culture doesn't value the sport and thus doesn't spend money on it, or they must spend too much time earning to feed themselves that they can't train.

Or that particular person has just never tried the sport. Or there are people who are actually more genetically suited to the particular sport but are discouraged from trying because they hear the current theories on what makes a genetically suitable athlete for that sport.

All we know is that Kenya as a country has the ability to produce excellent marathon runners. To heap all of that on "genetics" is grossly short-sited.

I think genetics has a lot to do with the success of Kenyan long-distance athletes. There are forty-two ethnic communities in Kenya, yet pretty much every long-distance runner you have ever heard of is from the Kalenjin community. If it were a matter of the country loving the sport, there could be a wider spread among the communities in Kenya.

Do you know anything about the comparable economic stability of these communities? Do you know anything about their own cultural differences?

People in my hometown love baseball. The next town over they love football. My hometown has never produced a professional or semi-pro football player, and the next town over has never produced a professional or semi-pro baseball player. But they each have had one or two people at least show up on the rosters of a professional team in their favorite sports. That's a difference of 11 miles, with highly mobile people who do intermarry between towns.

There can be significant enough differences in the culture of particular communities to allow for varying sports values. I would expect smaller towns to tend to emphasize one sport over all others, to the point that the townspeople in large part will live and breath that sport in a way that people in larger communities with more diverse sports options would not.

yes, cultural differences and training are important for sporting success. this still can hardly explain the pattern pointed out above...

We know that subpopulations of humans vary drastically by phenotypes relevant to athletic performance. The Dutch average adult male height is the highest on the planet at 6'1". African pygmies separated from their Bantu relatives 4,000 - 5,000 years ago, and have since evolved to have an average male height of 4'11". Others are intermediate - the Japanese have an average male height of 5'7".

Within a breeding population, height tends to follow a normal distribution. Depending on the standard deviation, there will be a few Japanese taller than the average Dutch. But there will be far more Dutch than Japanese among the very tallest men. This is a simple example, but in a sport where height matters, like basketball, there will be far more Dutch who are good at it than Japanese, and far more Japanese than pygmies.

Certainly culture matters, especially in sports where intelligence matters more and raw physical talents matter less. But genetics also matter.

It doesn't seem that height has everything to do with genetics, if we observe the average heights of taller countries in the past. Things like diet and perhaps healthcare are also factors. When it comes to the Dutch, they didn't always use to be the tallest:

- http://suite101.com/article/why-are-the-dutch-so-tall-a55753

And if you select those extremely tall Japanese people and transplant them to the United States, they will be far more likely to find success in basketball than if they had stayed in Japan. The Japanese culture (assuming) does not value basketball as a sport. Being in Japan, those athletes won't have the chance to develop their skills to the degree that they would elsewhere.

Yes, it could be said that the Japanese do not value basketball because they have historically not found success in it on the international scale, which would be because of their genetic predisposition to being shorter than even the Chinese. Genetics shape culture and culture can reinforce genetics. But it's not all about genetics. That's my entire point: there is no single variable that can claim why Kenyans run so well. But people want to say that it's genetics that make a good marathoner. That's just not the case, it takes both genetics and environment.

This is not a novel concept, but for some reason when it comes to lay people talking on the internet about sports, they don't want to admit it. The world is complex, there are shades of grey, nothing is black and white.

I thought there were documented expressions in west Africa of particular genes that seem to make for great runners, the same way the Sherpas have been proven to poses genes that make them more suited to mountaineering than populations without similar high-altitude adaptations.

Genetics set the ceiling.

Try as they might, achondroplastic dwarves will never make it to the NBA, and severe, congenitally retarded people will never have a significant, active contribution to human knowledge.

These are off course extreme examples. There are several ways to be a good basketball player, or to become an intellectual (athleticism is less open to variety).

But for an equal amount of work some people will end up better at some tasks than others.

I don't see how either example supports your argument.

If Bolt had pursued cricket, rather than athletics, he would have looked different, too, but that does not mean he isn't a genetically good fit for a sprinter. Now, if you had a pair of identical twins where both trained identically, weren't hit by different strokes of luck/misfortune, but got wildly different physique, that would have been an argument.

As to your second argument, the fact that we do not know what genetic makeup makes a fast sprinter does not imply that there is no genetic makeup that makes a fast sprinter.

Yes and No depending on the sport.

1. Chess is a game traditionally considered to be strongly co-related to IQ (which is strongly heridetary), but a survey of Grandmasters find that they have generally average IQ. What they did have a lot of, was years of experience and dedication, and also probably very good memories.

2. Basketball is a game where height (which is also strongly heridetary) is very important (the average height of a NBA player is 6' 7"). What are the odds of a man who is 5' 7" becoming a great world-class player? Sure, you could name some guy who fought all odds to rise to the top. But the key word here is odds, and genetics plays a huge role in stacking up the odds.

This line falls apart because people will rightly argue over what is a sport. If we then include chess, then why not programming? Or education in general? Education is not competitive, but we can compare and rank.

In the end it all becomes a horrible mess.

In then end I tend to think the genetics must have an impact all over society and culture, and, well, that's that.

Listen to David Epstien being interviewed about his book "The Sports Gene" here. http://snd.sc/15G4kbd

Go to 1:00.45 unless you want to here about Gaelic Football etc.

Perhaps you underestimate how incredibly small the margins are in sport?