It's amazing that it only takes centuries. Under natural selection, species traits stay relatively stable for thousands or even millions of years.
I suppose that means natural selection tends to have more of a pronounced effect when there has been a severe environmental change that wipes out a large fraction of the population and leaves behind only those with adaptive mutations. Otherwise, the adaptive mutation stays in the population but doesn't proliferate excessively. Selective breeding can then be interpreted as an extreme version of environmental stress.
I had previously imagined that evolution was a slow process but it seems that its more of a punctuated equilibrium, where when changes occur they occur quickly.
(Caveat: not a biologist, just a layperson speculating and learning.)
It doesn't "take" centuries, it's just been going on for centuries. You can probably develop a very unique cultivar in a single lifetime. This is quite common in the horticultural industry and is especially feasible with weedy species like Brassicas
And the stability of the traits is mostly due to careful management. Most of these vegetables will very easily hybridize
In the Andes there are still traditional farmers that maintain over 300 varieties of potatoes. Each one has a name and a history. Some are only ornamental, some are only eaten in soups, some are medicinal, some are a bright purple, some are extremely long, some look like giant pinecones. Just look at the incredible images in this article
https://www.theguardian.com/environment/2019/nov/29/how-peru...
I'm just glad this only applies to plants, and possibly animals, and not humans.
The argument against eugenics is not "it doesn't work even in theory."
Exactly.
It seems to be a law of HN that any discussion of genetics descends into a debate about the existence of übermensch and untermensch. :(
It's a law of discussion of human genetics that they are always smeared as about superiority. We can conserve and differentiate between wolf subspecies without being called Eurasian wolf supremacists. So clearly this 'misunderstanding' is deliberate.
You think it maybe applies to more than just eugenics? Perhaps to the dogma that we are all the same?
In fact, punctuated equilibrium is quite compatible with what you describe as "the dogma that we are all the same".
Punctuated equilibrium theory was proposed in the early 1970s by Stephen Jay Gould, who also wrote The Mismeasure of Man, a critique of biological determinism.
https://en.wikipedia.org/wiki/Punctuated_equilibrium
Yet punctuated equilibrium does not apply to cabbage, dog breeds, wolf varieties, and countless others. There are 37 subspecies of wolf, 10 of brown bear (yes, only brown bear. Other bears have their own subspecies each), and 47 red fox subspecies. Man alone is the great exception, unaffected by geographical separation and restricted gene flows.
> biological determinism
That term itself is a strawman - the argument is not that biology and genes fully determine behavior and life outcomes, merely that they affect it. As an aside, not only was Mismeasure of Man debunked (the skull measurements were not biased [1,2]), attacking craniometry in the era of genetics is like attacking alchemy. He should spend his time attacking PCA plots of the human genetic distribution [3]. Of course he does not, because he would prefer people remained ignorant of that.
It's sad that 166 years after On the Origin of Species, we still haven't accepted that we are not immune to natural selection.
[1] https://en.wikipedia.org/wiki/The_Mismeasure_of_Man#Reassess...
[2] https://www.nytimes.com/2011/06/14/science/14skull.html
[3] https://commons.wikimedia.org/wiki/Category:Principal_compon...
> Of course he does not, because he would prefer people remained ignorant of that.
That's certainly one hypothesis, but here's an alternative one that I'd like you to consider: he's not doing that because he died in 2002. (https://en.wikipedia.org/wiki/Stephen_Jay_Gould)
> Man alone is the great exception, unaffected by geographical separation and restricted gene flows
Extant bears have never invented the wheel, wolves spend more time eating horses than domesticating them, and despite what you might see on certain corners of the internet there has never been a vulpine Columbus. (To clarify, humans move around a whole lot more than most animals)
> he died in 2002
Cavalli-Sforza, Menozzi and Piazza measured genetic differences between human populations using the fixation index in 1994 [1]. He was not ignorant of genetics, he just chose to shift attention to craniometry instead. And even now that we have far better tools and knowledge, people choose to focus on outdated arguments instead, because they give the answers they want. E.g. by bringing up Gould when his work is no longer relevant.
> To clarify, humans move around a whole lot more than most animals
By what mechanism do you think the visible physiological distinctions between human populations arose? Clearly humans don't (or haven't up to very recently) moved around enough to even them out.
You think those are the only traits that haven't been evened out?
[1] https://en.wikipedia.org/wiki/Fixation_index#Genetic_distanc...
> By what mechanism do you think the visible physiological distinctions between human populations arose?
Genetic drift, mostly, with some founder effect mixed in.
nervous laughter