"50 Years Ago, Kenya Established Its Distance Running Dominance
The African country became a medal-winning power at the British Empire and Commonwealth Games in August 1966, and hasn’t looked back."
Obviously (1) getting invited to the event and (2) learning the rules of a particular event are major selection factors when drawing conclusions from event results.
The dominance of Kenyan athletes in these events is probably mostly due to altitude rather than genes. There's certainly no direct evidence of any significant genetic component, whereas we know that growing up at higher altitudes confers certain advantages.
It's both. High-altitude populations do show genetic adaptations. There is in fact plenty of evidence of genetic adaptation to altitude. If you grew up at high altitude and are not of Kenyan/Ethiopian descent, you'd be pretty well-adapted, but not as well on average.
Maybe, but that's largely speculative. We haven't identified any particular combination of genes that (a) is almost unique to the Kenyan population and (b) has been shown to have a significant effect on long-distance running performance.
All we really know is that - not surprisingly - people who grow up at high altitudes tend to use oxygen a bit more efficiently than people who don't.
But such genomes exist: they literally define the people who have lived in the high-altitude regions around the Rift Valley for many generations. And the genetic component to Ethiopian and Kenyan dominance in long-distance running is well-researched. Far more is known than your comment suggests, for example:
Of course, genetics interact strongly with environment. That's precisely why someone raised in a high-altitude Ethiopian community but whose ancestors are from, say, the Netherlands would not be expected to be as well-adapted to altitude (or long-distance running) compared to their historically Ethiopian neighbours, all else being equal.
There's no consensus in the literature about the role of genetic factors in Kenyan dominance. For any X you can find journal articles arguing that X is genetically determined. See e.g. https://journals.humankinetics.com/view/journals/ijspp/7/2/a... for a more balanced perspective.
>That's precisely why someone raised in a high-altitude Ethiopian community but whose ancestors are from, say, the Netherlands would not be expected to be as well-adapted to altitude (or long-distance running) compared to their historically Ethiopian neighbours, all else being equal
You say "would not be expected to be" because, of course, no-one has actually done this experiment and no-one knows what would actually happen. Nor indeed would we be able to verify that any given individual from the Netherlands does in fact lack the putatively relevant genes, since we don't know what they are.
There's continuing scientific inquiry into determining how much of Kenyan and Ethiopian dominance (specifically, dominance by members of the Kalenjin tribe) in long-distance running is due to genetic factors. However, the point still stands that genetics are certainly a factor, by an amount that is unknown (and possibly unknowable given how hard it is to design interventional experiments). There is no scientific debate on this front that I'm aware of. For example, here's an article published in 2012 that summarizes research (and controversies) surrounding the genetic component of distance running: https://www.theatlantic.com/international/archive/2012/04/wh...
The abstract to which you linked points out that "Kenyan and Ethiopian distance-running success is not based on a unique genetic or physiological characteristic." That seems like a strawman, as I don't think anyone ever claimed that any single characteristic or gene has been making all the difference. The abstract calls out "favorable somatotypical characteristics lending to exceptional biomechanical and metabolic economy/efficiency." Sure, but how much of these characteristics and exceptionally favourable response to training and living at altitude is potentiated by genetics? The answer of "none" would be an extraordinary claim requiring extraordinary evidence.
> You say "would not be expected to be" because, of course, no-one has actually done this experiment and no-one knows what would actually happen. Nor indeed would we be able to verify that any given individual from the Netherlands does in fact lack the putatively relevant genes, since we don't know what they are.
I'm not aware of any interventional study that, say, separates high-altitude-native twins so that one twin grows up at low altitude but with everything else being equal. That sounds completely impractical. However, there exists observational evidence from human migrations to and from high altitude. Some examples:
Finally, to address your earlier comment that "all we really know is that - not surprisingly - people who grow up at high altitudes tend to use oxygen a bit more efficiently than people who don't," this is a grossly inaccurate summary of scientific understanding of the multiple examples of convergent evolution that have produced genetically altitude-adapted populations in Kenya/Ethiopia, the Andes, and Tibet.
> However, the point still stands that genetics are certainly a factor, by an amount that is unknown
If you remove all constraints on effect size, then everything is a factor in everything. There is no strong reason to think that genes unusually prevalent among Kenyans play a large role in success at distance running. Note that this is not identical to the claim that genes do not play a large role in success at distance running. Certainly, performance in any given sport is significantly influenced by genetic factors (though the details are not well understood). But the following is not a good argument:
Genes significantly influence athletic performance
Keynans are great at distance running
|- Keynans have genes that make them better at distance running.
>The abstract calls out "favorable somatotypical characteristics lending to exceptional biomechanical and metabolic economy/efficiency." Sure, but how much of these characteristics and exceptionally favourable response to training and living at altitude is potentiated by genetics? The answer of "none" would be an extraordinary claim requiring extraordinary evidence.
The article points out that Somalians and Kenyans don't (on average) have particularly similar somatotypical characteristics, and yet both nations have produced exceptional distance runners.
>Finally, to address your earlier comment that "all we really know is that - not surprisingly - people who grow up at high altitudes tend to use oxygen a bit more efficiently than people who don't," this is a grossly inaccurate summary of scientific understanding of the multiple examples of convergent evolution that have produced genetically altitude-adapted populations in Kenya/Ethiopia, the Andes, and Tibet.
This is just bluster. We know little about the genetic details, and even less about any possible effects on elite athletic performance.
> |- Keynans have genes that make them better at distance running.
I've been discussing Kenyan and Ethiopian runners for brevity, but as you point out, I should have been more specific: this chain of reasoning should conclude with the much more compelling observation that "from 1980 on, ~40% of the top honours available to men in international athletics at these distances (Olympic medals, World Championships medals, and World Cross Country Championships honours) have been earned by Kalenjin." https://en.wikipedia.org/wiki/Kalenjin_people
> The article points out that Somalians and Kenyans don't (on average) have particularly similar somatotypical characteristics, and yet both nations have produced exceptional distance runners.
The Kalenjin identity predates modern borders of Kenya and Ethiopia, which torpedoes the "but multiple nations have produced elite runners" argument. They are massively disproportionately successful at distance running, and it's well-established that their specific genotypes are key to their success -- not the only key, but a major part.
None of this is "bluster." We can politely disagree here all we want, but the fact is that we both have near-instant access to reams of supporting evidence for the fact that Kalenjin genes uniquely predispose them to distance-running prowess, similar to how the Bajau of Southeast Asia are genetically predisposed to have 50% bigger spleens as a free-diving adaptation (https://en.wikipedia.org/wiki/Sama-Bajau#Free-diving_adaptat...), or how Tibetans are adapted across multiple genes to thrive at high altitude in a different way from Kalenjin or Andeans (https://www.theguardian.com/science/2010/jul/02/mutation-gen...), or any of the other specific examples of genetic adaptation to ancestral environments whose existence might be uncomfortable to some, but are nevertheless real.
That's pretty vague. You keep saying that things are "well-established" by science, but don't provide proper citations. The literature on Kenyan athletic performance is mostly pretty speculative and inconclusive. The article that you yourself cite in an earlier comment (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4037248/) has a very tentative conclusion:
"A critical analysis of this unique phenomenon has shown that these athletes do not descend from a single isolated genetic profile.4 The data suggest that the genes most studied and associated with performance in aerobic endurance running (ACE and ACTN3) do not seem to fully explain the success of these athletes. It seems unlikely that Africa is producing unique genotypes that cannot be found in other parts of the world. So far, the evidence shows that the subjects’ phenotype (molded over time by several factors) seems to have greater influence than their genotype in their long-distance running success.4 While recognizing that this field of study is at an early stage of understanding, the available results show that the identified candidate genes for human performance neither determine nor exclude the possibility of athletic success. Although, the right choice of parents can help in the search for athletic success, this is not the deciding factor between success and failure in sport.4"
"50 Years Ago, Kenya Established Its Distance Running Dominance
The African country became a medal-winning power at the British Empire and Commonwealth Games in August 1966, and hasn’t looked back."
Obviously (1) getting invited to the event and (2) learning the rules of a particular event are major selection factors when drawing conclusions from event results.