Gotcha. Which is why I haven’t been mentioning race, have I? The social construct of whiteness and blackness in America isn’t what I am referring to.
A greyhound and a pug share genes, btw. They are the same species. You can’t tell me that a healthy pug would ever beat a healthy greyhound in a 100m sprint.
I mean lets just look at Africans that are black. Of course there is a ton of ethnic groups, tribes, whatever within that category and each one of those would have a different, however slightly, distribution of physical traits. If we just had a sport called “grow tallest” nobody would have any issue with recognizing that the Pygmies would be poorly represented in the top 0.1% of that sport.
Pygmies are a good group because as a group their physical differences are profound. And even the PC won’t claim that if the pygmies just lived in a destitute area and that the only way out was to excel in running, swimming, or jumping that pygmies would hold 99 out of the top 100 records in that sport. So it’s not much of a stretch to think that continents apart and several hundred if not thousands of years of evolution that some groups within these huge continents would not have diverged in such a way that genetically speaking their top outliers are 0.5% better at some random task or sport.
Ok. Understood. So is the problem with the question the idea that different groups have different distributions which lead to different outcomes at the top levels of sport?
This is possible, but considering that at different times different groups have dominated various sports, the present breakdown-by-race of various sports doesn’t necessarily mean anything more for human genetics than the early 20th century domination of basketball by Jews.
So maybe there is some advantage for certain groups in certain sports, but just 'cause so many of the best sprinters are Jamaican (and indeed, IIRC, from a certain part of Jamaica) doesn’t mean that those of Jamaican descent have some genetic advantage for sprinting. It could very well be cultural, which could include things like nutrition, childhood activities, environment, etc.
Pigmentation is often cited as a trait that can evolve remarkably rapidly, in say, less than 10,000 years.
Pigmentation is often cited as an example of a human trait that can evolve remarkably rapidly, in even less than 10,000 years!
To use Darwin’s terms, it’s “natural selection” vs. “artificial selection”. Consistent with your post, the main difference between natural and artificial selection, in terms of the rate of change in gene frequency, is fitness ratio. With natural selection, a beneficial trait gives some increase in fitness, say a 1% advantage. With artificial selection under ideal circumstances (no undesirable mating), the trait can be given a 100% advantage. Of course, as mentioned above, slavery is far from ideal conditions for artificial selection.
“It’s TWOO, it’s TWOO!” She wasn’t actually lying. She was merely jumping to conclusions based on results using an insufficient sample size.
In terms of height, at least, remarkably little variation compared to other groups. I worked with a Chinese man who was 6’5". I asked him about it one day, mentioning that though we think of people from India as tending to be small, there are populations of Indians of remarkable height. His reply was that among 50,000 students at his university (of Beijing, IIRC), he was the tallest. Not a lot of diversity on that point! (Admitedly, this doesn’t argue against the point you were making. Just an interesting observation.)
Excellent point, and well put.
80% of the diversity in the human genome is found in central sub-Saharan Africa. That may seem odd, but it’s typical of “source” populations. For analogy, there is far more linguistic variation in the southern tip of Taiwan, the source of the Polynesian culture, than in all of Polynesia (from Madegascar to Easter Island!) The reason is fairly simple, and the same in both cases: the source populations were around for a very long time compared to the time between the migration and now, so there was a great deal of diversity in the source. Only a sample of the source population migrated, omitting a large portion of that diversity. While significant diversity has arisen since then, the time is far too short for it to have come anywhere near the original source population diversity.
The first one (Hardy-Weinberg equation) simply gives the equilibrium gene frequencies of two alleles for a given gene, if there is no selective pressure:
p = prob(a1) where a1 is “allele 1” for that gene, and “prob(x)” is the probability (aka gene frequency) of that allele in the population
q = prob(a2)
Note that p + q = 1. The equation (derived in the PDF based on trivial probability) is:
p^2 + 2pq + q^2 = 1
If we add a coefficient to each of the three terms indicating the relative fitness of that genotype, we get the “fitness equation”, which shows how gene frequencies will change after one (ideal) generation. In practice, generations overlap, but the discrepancy between models that overlap and those that don’t is less than a factor of 2.
I’ve had some fun fiddling with this equation and the introduction of a new mutation, assuming the population is all one allele, assigning a beneficial fitness to the mutation, and seeing how many generations it takes to dominate in the population. (For my simulation, I assumed the same fitness for one or two copies of the mutation.) The growth is nearly exponential – it looks very exponential at first but peters out as it becomes a significant fraction of the population*. The startup from a single individual in a large population takes a lot of generations, but once it hits one or two percent, it takes over remarkably quickly, as I recall.
I have a python script somewhere; maybe I can even still find it.
This is very tangential to the OP’s question, but posted just in case someone wants to fiddle with the math. As usual, beware the layman’s flaw. Using an equation we don’t quite understand can lead to invalid results! But still I feel it’s illuminating, as long as we don’t try to apply it to too specific a situation, where reality kicks in and frequently kicks us in the butt.
I suspect it amounts to the difference between two exponential equations, where at first one term is nearly zero but eventually rises to near equality.
There is a simple program , AlleleA1 written by Jon C Herron in RealBASIC, that does much of this. Can also simulate selective pressure and genetic drift. Some of his other programs can similarly be used to look at population genetics issues.
I could only hope that Dopers would play around with it a bit before making ridiculous statements on population genetics issues.
How would that model be of any use? Reality shows that different groups based on relatedness have different characteristics. To assume that these different characteristics have no real world advantages in real world situations or activities is incorrect.
When white people “dominated” basketball there was massive institutional racism. Black players played in their own leagues. In the face of desegregation some owners didn’t want black players anyway because they didn’t think white audiences would want to watch a team with so many black players. It became clear pretty fast that if you wanted to compete you had to get black players because guys like Wilt, Russell, Oscar, etc. were dominating to an extent that won’t ever be seen again. The NBA was majority black in just a couple years, by the end of the '60s.
You could get white players to dominate again, just ban all the black players. Who wouldn’t want to watch a league filled with Kevin Loves and Kyle Korvers?
Nope. It is, instead, demonstrating an understanding of the statistical science of population genetics.
The centuries of slavery were simply too short a time to have made a meaningful change in the genetic make-up of the enslaved population.
It’s like a creationist demanding to see a cat change into a dog. It doesn’t happen over observable time-periods. Significant evolutionary change requires more generations than slavery lasted.
I also pointed out that, during the period of slavery, there were many isolated regions of reproduction. Slaves in New Orleans would not have mixed genes with slaves from Kentucky in any useful numbers. The genetic distribution of all slaves could not possibly have been affected in the same way.
The fantasy is a simple-minded, even childish degradation of the reality.
(Joseph Goebbels was opposed to the Holocaust – the putting of massive numbers of Jews to death in forced labor camps – because, if the weak died and the strong survived, the program would be breeding “super-Jews.” Goebbels was an idiot.)
