The Campaign Builder's Guild

It had traditionally been assumed that the Caucasian, or White, race developed fair skin, flaxen hair and bright eyes as adaptations against the low-light areas of Pleistocene Europe.

However, recent evidence has found that these characteristics were actually one-time mutations that activated AFTER the last ice age ended, which meant that Cro-Magnon man, at the height of the ice age, may have been as dark as their brethren back in Africa. 

http://www.sciencemag.org/news/2015/04/how-europeans-evolved-white-skin

http://www.livescience.com/42838-european-hunter-gatherer-genome-sequenced.html

http://www.irishcentral.com/roots/the-light-skin-of-the-irish-can-be-traced-to-india-and-the-middle-east-239166271-239671671.html

Where did these mutations come from? Why did they activate in the time that they did and not sooner? And without these mutations, would the seven billion people currently living on Earth be uniformly black-skinned?

I'm not sure if there's a strong, easily identifiable reason apart from random chance for a given mutation occurring or why they have to be one-time (given a long enough timeline I don't see why similar mutations couldn't occur). Obviously natural selection is probably largely responsible for why a trait like that spreads. From what little I turned up, though, it seems as if the light skin of various East Asian populations can't be entirely traced to the same set of genes as those of European fair skin, so it's not like there's a single mutation solely responsible for all kinds of fair skin. It therefore seems plausible to me to conclude that if the mutation that led to European fair skin didn't occur, given a long enough time line and enough population growth, other mutations would well occur leading to different varieties of fair skin.

This all armchair genetics, though, and there's probably no way to properly answer this with any confidence without massive quantities of research.

Quote from: JohnWDaileyGLEIt had traditionally been assumed that the Caucasian, or White, race developed fair skin, flaxen hair and bright eyes as adaptations against the low-light areas of Pleistocene Europe.

I know you're into scientific rigour, so it might be worth pointing out that the term "race" doesn't strictly apply in a genetic context. We can trace for genetic ancestry and kin groups, certainly, and determine clusters of alleles, but race as defined by surface concepts like skin colour doesn't really exist biologically in a way that maps to the social and cultural constructions of race that persist today - those are pretty much folk taxonomies leftover from nineteenth-century pseudoscience.

Quote from: SteerpikeI know you're into scientific rigour, so it might be worth pointing out that the term "race" doesn't strictly apply in a genetic context. We can trace for genetic ancestry and kin groups, certainly, and determine clusters of alleles, but race as defined by surface concepts like skin colour doesn't really exist biologically in a way that maps to the social and cultural constructions of race that persist today - those are pretty much folk taxonomies leftover from nineteenth-century pseudoscience.

That does not change the maybe personal observation that diversity breeds curiosity.

Quote from: JohnWDaileyGLE That does not change the maybe personal observation that diversity breeds curiosity.

I don't see how the two are related in the context of the discussion. I'm not really sure what you mean (are you using "breeds" metaphorically, or genetically here?).

Metaphorically.

Then I guess I'm lost. How does this pertain to your original question?

It pertains because human diversity is high, and that is bound to make some people curious.

Flood basalt catastrophes were something that never happened in human history, but they were common much earlier in Earth's history. The one that comes to the mind of the mainstream were the Siberian Traps, believed to be the culprit for the worst mass extinction in history, killing off 70% of terrestrial species and 95% of marine species, covering a volume of one to four million cubic kilometers and a maximum thickness of 4500 meters.


These eruptions happened 252 million years ago, more than enough time for the forces of erosion and soil accumulation to reduce the Siberian Traps into a pale shadow of their former self.


In this alternate scenario, the Siberian Traps still erupted, but with the following differences:


   Date: 60-43 million years ago, so slowly that if it were responsible for a mass extinction, it wouldn't have been dramatic enough for anyone to notice.
   Volume: 59-77 million cubic miles
   Maximum thickness: 2.5 miles

43 million years of erosion and soil accumulation would have given Eurasia a drastically different landscape as opposed to 252 million years of the same thing. Siberia back home is pretty remote and its geographic diversity makes it pretty challenging real estate. Would this Siberia be even more so? Would we still expect to see steppe, desert and tundra in Russia or would mountains and plateaus be more prevalent?

It isn't necessary to create a new thread for each new question you want to ask or concept you want to talk about. I've merged your last couple of threads together. Please continue to use this unified thread for further discussion.

Quote from: JohnWDaileyGLE
Flood basalt catastrophes were something that never happened in human history, but they were common much earlier in Earth's history. The one that comes to the mind of the mainstream were the Siberian Traps, believed to be the culprit for the worst mass extinction in history, killing off 70% of terrestrial species and 95% of marine species, covering a volume of one to four million cubic kilometers and a maximum thickness of 4500 meters.


These eruptions happened 252 million years ago, more than enough time for the forces of erosion and soil accumulation to reduce the Siberian Traps into a pale shadow of their former self.


In this alternate scenario, the Siberian Traps still erupted, but with the following differences:


   Date: 60-43 million years ago, so slowly that if it were responsible for a mass extinction, it wouldn't have been dramatic enough for anyone to notice.
   Volume: 59-77 million cubic miles
   Maximum thickness: 2.5 miles

43 million years of erosion and soil accumulation would have given Eurasia a drastically different landscape as opposed to 252 million years of the same thing. Siberia back home is pretty remote and its geographic diversity makes it pretty challenging real estate. Would this Siberia be even more so? Would we still expect to see steppe, desert and tundra in Russia or would mountains and plateaus be more prevalent?

Short answer, yes - but it's very difficult to say to what degree. These questions are very difficult and my answer or anyone else's will be inherently naive, because we can't fully predict to what extent the changes you have proposed in your posts will have. If Siberia is more mountainous, and remains so for 60 million years, it's not going to be a matter of simply changing the local landscape; it could have profound effects on the entire planet once you factor in differences in weather patterns and movement of flora and fauna. At minimum, you will find that higher elevation will cause some part of the land around the area to be part of a more extreme rain shadow.

On that note, your proposal of a much more gradual eruption complicates other fundamental ideas you have proposed, as without the corresponding extinction event, how do you argue that humans even came to be anywhere near the same time, or in the same manner, as you have suggested? Chaos theory dictates that tiny changes in a system can result in drastic differences in their future behaviour - modelling a large change as many minor changes, you can't realistically expect anything to be the same. You are likely to see dampening effects that prevent incredibly extreme scenarios from arising, but it's safe to say that some of the prehistoric events you are altering will matter more than you have thus far proposed.

Speaking from experience putting a lot of time into hyper-realistic and overly scientific details for my own work, this might not be worth your trouble. The way I see it, either you continually take part in these - admittedly entertaining - thought experiments, and end up struggling to be satisfied with the amount of detail you've invested; or you provide yourself and your work with an upper bound of effort on such problems, in which case the evidence and data you present to us with your questions is already more than enough to help you design your alternate Earth. It can be frustrating accepting a lower level than what you, yourself, are expecting, but in the end it'll be a small number of people who are concerned about your work for the inclusion and/or exclusion of these tiny details.

Quote from: sparkletwist
It isn't necessary to create a new thread for each new question you want to ask or concept you want to talk about. I've merged your last couple of threads together. Please continue to use this unified thread for further discussion.

I beg to differ.  In order to make a fictional world believable, one has to ask one question at a time.  Dumping them all in one post would be both overwhelming and confusing.

Quote from: JohnWDaileyGLEIn order to make a fictional world believable, one has to ask one question at a time.  Dumping them all in one post would be both overwhelming and confusing.

There's a difference between a post and a thread. You can ask a series of questions one at a time in a thread, they don't need to be crammed into a single post.

Quote from: JohnWDaileyGLE
I beg to differ.

This forum is kind of casual and informal so I haven't really felt the need to use a red-texted "mod voice" or anything, but I'd just like to make clear that me asking you to stop creating excessive new threads about your setting was in an official capacity and is not open for debate.

Please convey any future questions or concerns about this issue to me privately.

Back to the original topic(s) presented, I'm sort of curious about where this all is going. When I was more active, I don't think anyone ever called me innocent of obsessing over minutae, but these whatifs seem really subtle and I'm wondering whether there's an endgame here or if we're just practicing our high-level esoteric alt-history chops.