If civilization falls, will people go back to their natural habitat?

[Unitive_Mystic]

So I have been studying evolution and seeing how people from different parts of the world adapt to their enviroment. So the data I have gathered so far is that humans with a darker skin tone gives them the advantage in areas closer to the equator, people with lighter skin tone are adapted to lower light levels further away from the equator. Here is the further information.

"Surprisingly, the team found no immune genes under intense selection, which is counter to hypotheses that diseases would have increased after the development of agriculture.

The paper doesn’t specify why these genes might have been under such strong selection. But the likely explanation for the pigmentation genes is to maximize vitamin D synthesis, said paleoanthropologist Nina Jablonski of Pennsylvania State University (Penn State), University Park, as she looked at the poster’s results at the meeting. People living in northern latitudes often don’t get enough UV to synthesize vitamin D in their skin so natural selection has favored two genetic solutions to that problem—evolving pale skin that absorbs UV more efficiently or favoring lactose tolerance to be able to digest the sugars and vitamin D naturally found in milk. “What we thought was a fairly simple picture of the emergence of depigmented skin in Europe is an exciting patchwork of selection as populations disperse into northern latitudes,” Jablonski says. “This data is fun because it shows how much recent evolution has taken place.”

Anthropological geneticist George Perry, also of Penn State, notes that the work reveals how an individual’s genetic potential is shaped by their diet and adaptation to their habitat. “We’re getting a much more detailed picture now of how selection works.”

That being said, in today's modern day civilization we have the technology to help us live outside our natural habitat (sunscreen, sunglasses, skin cancer treatment). If civilization falls we won't have access to this equipment, sunglasses break and sunscreen expires. Where will people of different races go? Will Caucasian and Europeans move up north as well as Afircans and Mexicans move down south? Will they move at all? If not, how will they live outside their natural habitat without modern conveniences.

[Scott of the Antares]

Surely Mexicans and Africans can live anywhere, it is whites that need the sun cream and sunglasses you mention. And whites were in Africa,  the Middle East, India, the Orient and Australia before these inventions so I imagine they wouldn’t have any problem doing it again, without these devices.

And I reckon that if civilisation falls, hunter gatherers inherit the earth. 

[Unitive_Mystic]

5 minutes ago, Scott of the Antares said:

Surely Mexicans and Africans can live anywhere, it is whites that need the sun cream and sunglasses you mention. And whites were in Africa,  the Middle East, India, the Orient and Australia before these inventions so I imagine they wouldn’t have any problem doing it again, without these devices.

And I reckon that if civilisation falls, hunter gatherers inherit the earth. 

Well I wouldn't say Afircans can live anywhere. Their skin needs more sun because the melanin levels in the skin makes you need more sun to get the proper amounts of vitamin D.

So if people can live anywhere, why did they evolve differently if they didn't need to? Is it just survival advantages?

Edited June 22, 2018 by Unitive_Mystic

[StringJunky]

7 minutes ago, Scott of the Antares said:

Surely Mexicans and Africans can live anywhere, it is whites that need the sun cream and sunglasses you mention. And whites were in Africa,  the Middle East, India, the Orient and Australia before these inventions so I imagine they wouldn’t have any problem doing it again, without these devices.

And I reckon that if civilisation falls, hunter gatherers inherit the earth. 

Actually, dark skin has problems with D deficiency in northern lattitudes from less sun and a tendency towards lactose intolerance which compounds the problem.

Edited June 22, 2018 by StringJunky

[Scott of the Antares]

2 minutes ago, Unitive_Mystic said:

Well I wouldn't say Afircans can live anywhere. Their skin needs more sun because the melanin levels in the skin makes you need more sun to get the proper amounts of vitamin D.

I might have used too broad a brush there, so apologies, you are right. But African people do live in the U.K.; am I totally unaware of a practice employed by them to counter this?

[Unitive_Mystic]

18 minutes ago, Scott of the Antares said:

I might have used too broad a brush there, so apologies, you are right. But African people do live in the U.K.; am I totally unaware of a practice employed by them to counter this?

Vitamin D deficiency is present in almost all diseases and people with dark skin in northern latitudes are much more prone to getting vitamin D  deficiency. What do they do about it? Well, there a vitamin D pills to help you, do all people with darker skin commonly do this? I imagine they would if they are vitamin D deficient, if they don't do anything about they probably don't know or care.

And yes, white people did survive the sun before sunscreen and they had a number of ways like

• Zinc oxide
• Wide brimmed hats
• When working in fields, a handkerchief or bandana to cover the neck
• Parasols
• Cocoa butter, Petroleum jelly Oils/ herb mixtures 
• Long hair
• Beards

These methods (besides long hair and beards, which will only make you hotter) will not be available after a civilization collapse because these things will not be manufacture. People can probably make some of these things but probably not because they will be to busy doing more important stuff like building, traveling, farming, and hunting.

However, vitamin D is much more valuable in a time of civilization collapse because you'll need to use alot more energy. So I suppose they would have a difficult time surviving.

Edited June 22, 2018 by Unitive_Mystic

[StringJunky]

1 minute ago, Scott of the Antares said:

I might have used too broad a brush there, so apologies, you are right. But African people do live in the U.K.; am I totally unaware of a practice employed by them to counter this?

UK health authorities are only just becoming aware of the implications of vitamin D deficiency in northern lattitudes in general but I imagine in time, if they are not now, will target people of colour in particular eventually. White people may need supplementation for half the year and probably black people may need all the time here. I think there will probably be more official publicity on this in time.

[Unitive_Mystic]

9 minutes ago, StringJunky said:

UK health authorities are only just becoming aware of the implications of vitamin D deficiency in northern lattitudes in general but I imagine in time, if they are not now, will target people of colour in particular eventually. White people may need supplementation for half the year and probably black people may need all the time here. I think there will probably be more official publicity on this in time.

So do you think people would have to return to the habitat they are adapted to for the most garaunteed survival in a situation of civilization collapse?

[StringJunky]

2 minutes ago, Unitive_Mystic said:

So do you think people would have to return to the habitat they are adapted to for the most garaunteed survival in a situation of civilization collapse?

In the long term, one might fair better over the other statistically but I don't know if it would be really significant at this point in human history. I think you'll get a better answer if CharonY sees this thread

[Ken Fabian]

With civilisation gone the means to relocate (easily) will be also. Lack of civilisation does not mean no tools or technology - especially since knowledge and remnants will mean people know a lot is possible. A whole lot of basic technologies will still be within reach, even if it's back to knapping knives out of stone.

Whether those living in less than ideal climate will be displaced over multi-generations by those who (from here) look better suited could depend on how long before civilisations develop again. Most places now tend to have mixed populations - the genes for dark skins and light skins will co-exist and mix in populations in all kinds of climates.

I think most humans will continue to have the capability of surviving in most locations, that the idea that there is an ideal climate or geography may not strictly apply, that ingenuity if not plain human stubborness that worked in our past will keep work in the future, regardless of location.

I doubt we would see any significant evolution any time soon - and the mixing of genetic heritages may make it less obvious. Or make it necessary for new traits to emerge. I suppose the most significant kind of evolution might be ongoing genetic flow - genetics from one population type to another - as mixed populations mix even further, perhaps (if isolated long enough) into a more homogenous population.

[Unitive_Mystic]

On 6/22/2018 at 10:50 PM, Ken Fabian said:

With civilisation gone the means to relocate (easily) will be also. Lack of civilisation does not mean no tools or technology - especially since knowledge and remnants will mean people know a lot is possible. A whole lot of basic technologies will still be within reach, even if it's back to knapping knives out of stone.

Whether those living in less than ideal climate will be displaced over multi-generations by those who (from here) look better suited could depend on how long before civilisations develop again. Most places now tend to have mixed populations - the genes for dark skins and light skins will co-exist and mix in populations in all kinds of climates.

I think most humans will continue to have the capability of surviving in most locations, that the idea that there is an ideal climate or geography may not strictly apply, that ingenuity if not plain human stubborness that worked in our past will keep work in the future, regardless of location.

I doubt we would see any significant evolution any time soon - and the mixing of genetic heritages may make it less obvious. Or make it necessary for new traits to emerge. I suppose the most significant kind of evolution might be ongoing genetic flow - genetics from one population type to another - as mixed populations mix even further, perhaps (if isolated long enough) into a more homogenous population.

You say that no civilization doesn't = No technology. Which I agree, but what l am saying is that technology that can only be created through modern civilization, such as vitamin D pills, sunscreen, sunglasses, brimmed hats, lenin clothing ect. So the white people living in the south will have to try and survive with no sun protection which can lead to negative affects and hinderance in survival. Black people in the north will have to survive vitamin D deficiency and in some cases lactose intolerance.

And people in certain countries with a large range of biomes like the United States will have a bunch of relocation opportunities. And I'm sure science organizations and religious ones will team up to help people gain their garaunteed survival, and that could include helping people relocate.

That being said my theory is that the different races will relocate to their natural habitat if possible.

[Ten oz]

On 6/22/2018 at 5:43 PM, Unitive_Mystic said:

Will Caucasian and Europeans move up north as well as Afircans and Mexicans move down south?

Is Mexican a race? Spain is in Europe and most people in Mexico are of Spanish ancestry. Also you are ignoring all the various darker skinned groups (darker than Caucasian) who live in northern areas like Inuits, Kazakhs, Mongolians, and the native Alaskan populations. 

When humans initial left warmer climates language either didn't exist or if it did wasn't nearly as established as it is now. Additionally agriculture hadn't been developed yet. Even if major govts fell Language and agriculture would still be know and those would enable people to continue live in a large variety of environments.   

On 6/22/2018 at 6:00 PM, StringJunky said:

Actually, dark skin has problems with D deficiency in northern lattitudes from less sun and a tendency towards lactose intolerance which compounds the problem.

This is true but as it applies to the OP overstated. Half the worlds population is Vitamin D deficient. It impact all ethnic groups. Moreover if civilization fell I seriously doubt vitamin D would make the list of top one thousand concerns those humans left would have for survival. 

Quote

 

Vitamin D insufficiency affects almost 50% of the population worldwide.[1] An estimated 1 billion people worldwide, across all ethnicities and age groups, have a vitamin D deficiency (VDD).[1–3] This pandemic of hypovitaminosis D can mainly be attributed to lifestyle and environmental factors that reduce exposure to sunlight, which is required for ultraviolet-B (UVB)-induced vitamin D production in the skin. Black people absorb more UVB in the melanin of their skin than do white people and, therefore, require more sun exposure to produce the same amount of vitamin D.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356951/

 

 

[Unitive_Mystic]

42 minutes ago, Ten oz said:

Is Mexican a race? Spain is in Europe and most people in Mexico are of Spanish ancestry. Also you are ignoring all the various darker skinned groups (darker than Caucasian) who live in northern areas like Inuits, Kazakhs, Mongolians, and the native Alaskan populations. 

When humans initial left warmer climates language either didn't exist or if it did wasn't nearly as established as it is now. Additionally agriculture hadn't been developed yet. Even if major govts fell Language and agriculture would still be know and those would enable people to continue live in a large variety of environments.   

About inuits...

skin tone is not all genetic: more melanin is produced when you are out in the sun. Sunlight exposure causes the optic nerve to signal the pituitary gland to release more melanin. Thus, you tan.

But Inuits vitamin D intake wasn’t dependent upon the sun. They get all that they need from their diet, heavy on types of fatty fish that are naturally rich in vitamin D. The plentiful amounts of the vitamin kept them from developing less melanin. In fact, before milk was fortified with D, people living outside of Northern Canada and Alaska loaded their diets with fishy products, such as cod liver oil, to get their daily supplement.

So despite their chilly climate and lack of sun exposure, it’s the Inuit diet that has kept them in their darker skin tone. Actually I wouldn't really consider them "dark" they are more tan than dark.
The Inuit experience very, very, high levels of reflected ultraviolet radiation long wavelength ultraviolet radiation from the snow. So their tan skin actually protects them from this high amount of UVA radiation.

So fish act as the supplement, while the murderous dosages of ultraviolet, they receive in the summer, acts as the driver for the retention of melanin in the first place.

 

Agriculture probably wouldn't allow people to live outside their natural habitat. What allows people to live outside their natural habitat is technology. Which wouldn't be here without modern civilization. And Yes, because of the development of our language, people of different cultures would still be able to communicate. However this doesn't mean that they would live together because they still have to follow the enviroment that they are suited for.

 

Vitamin D was a concern in a world without civilization. That is why Europeans developed white skin. Humans needed to adapt because their dark skin worked against them in northern latitudes.

Edited June 24, 2018 by Unitive_Mystic

[Ten oz]

19 minutes ago, Unitive_Mystic said:

Agriculture probably wouldn't allow people to live outside their natural habitat. What allows people to live outside their natural habitat is technology.

This is contradictory. Agriculture is a product of and requires the continued use of technology. 

19 minutes ago, Unitive_Mystic said:

Which wouldn't be here without modern civilization.

Define modern. Agriculture was developed 10,000 years before electricity and indoor plumbing. 

19 minutes ago, Unitive_Mystic said:

However this doesn't mean that they would live together because they still have to follow the enviroment that they are suited for.

Humans spread out of Africa across the whole globe into every environment the Earth has to offer (minus Antarctica) hundreds of thousands of years ago. Your notion that we (humans) would be limited to some garden of eden-esque placed based on ethnicity is disproved by history. 

Edited June 24, 2018 by Ten oz

[Unitive_Mystic]

1 minute ago, Ten oz said:

This is contradictory. Agriculture is a product of and requires the continued use of technology. 

Define modern. Agriculture was developed 10,000 years before electricity and indoor plumbing. 

Humans spread out of Africa across the whole globe into every environment the Earth hundreds of thousands of years ago. Your notion that we (humans) would be limited to some garden of eden-esque placed based on ethnicity is disproved by history. 

What I also mean is that (modern) agriculture wouldn't be here without modern civilization. Modern meaning that if civilization falls, all the technology that only gets into people's hands by using money, manufacturing companies, and an economy. Tractors could no longer be used, for an example. Also there are alternatives to agriculture, like permaculture, which would probably be used alot.

 

You are correct. Humans did spread out across the globe for thousands of years. And each part of the globe has a different environment. That is why we have people of different skin tones.

[Sensei]

30 minutes ago, Unitive_Mystic said:

Tractors could no longer be used, for an example.

There can be created (or modified already existing one) electric tractors.. There can be made tractors using ethanol/methanol as fuel, which can be produced from remains of agricultural production even by farmers by them self and being self sustainable.

Collapse of civilization does not necessarily means immediate lost of knowledge. Knowledge will be the most valuable thing you can have.

 

 

[Unitive_Mystic]

3 minutes ago, Sensei said:

There can be created (or modified already existing one) electric tractors.. There can be made tractors using ethanol/methanol as fuel, which can be produced from remains of agricultural production even by farmers by them self and being self sustainable.

Collapse of civilization does not necessarily means immediate lost of knowledge. Knowledge will be the most valuable thing you can have.

 

 

Only for a certain period of time. Tractors have parts that need replacement. Maybe a few generations down they will last.

[Ten oz]

8 minutes ago, Unitive_Mystic said:

What I also mean is that (modern) agriculture wouldn't be here without modern civilization. Modern meaning that if civilization falls, all the technology that only gets into people's hands by using money, manufacturing companies, and an economy. Tractors could no longer be used, for an example. Also there are alternatives to agriculture, like permaculture, which would probably be used alot.

If civilization were to fall people would still need to eat or they would die. Without agriculture humans would be force to be nomadic, constantly on the move relocating for food. Such a life style would come with far greater risks than anything related to vitamin d deficiency. To set roots down anywhere, northern or southern, agriculture would by a must. 

Agriculture was developed with the aid of tractors, companies, money, and etc. 

23 minutes ago, Unitive_Mystic said:

You are correct. Humans did spread out across the globe for thousands of years. And each part of the globe has a different environment. That is why we have people of different skin tones.

Right, but you are implying skin tone would drive migration. That isn't how it worked. People migrated and then over time in different environments there skin tones changed. That plus mixing with Neanderthal and Denisovan humans. 

"For example, the Neanderthal version of the skin gene POU2F3 is found in around 66 percent of East Asians, while the Neanderthal version of BNC2, which affects skin color, among other traits, is found in 70 percent of Europeans." https://news.nationalgeographic.com/news/2014/01/140129-neanderthal-genes-genetics-migration-africa-eurasian-science/

As I previously linked Half the world population, over 3.5 billion people, have a vitamin D deficiency. It isn't driving any sort of migration. If civilization fell vitamin D  would be what determines where people live. 

 

8 minutes ago, Unitive_Mystic said:

Only for a certain period of time. Tractors have parts that need replacement. Maybe a few generations down they will last.

Human created those part and are the ones building those parts today. To Sensei point, why do you think the knowledge for how to do such things would be lost?

[swansont]

On June 22, 2018 at 5:43 PM, Unitive_Mystic said:

"Surprisingly, the team found no immune genes under intense selection, which is counter to hypotheses that diseases would have increased after the development of agriculture.

Not sure I understand this. It's not an hypothesis. There are definitely diseases that jumped from animals to humans after agriculture was developed (e.g. smallpox) and are only sustained by having a certain population density

https://www.ncbi.nlm.nih.gov/books/NBK114494/

But AFAIK, the diseases became less virulent because they evolved that way, and that happened faster than humans were going to evolve immunity.

Also: "collapse of civilization" has not been defined particularly well.

[Unitive_Mystic]

59 minutes ago, Ten oz said:

If civilization were to fall people would still need to eat or they would die. Without agriculture humans would be force to be nomadic, constantly on the move relocating for food. Such a life style would come with far greater risks than anything related to vitamin d deficiency. To set roots down anywhere, northern or southern, agriculture would by a must. 

Agriculture was developed with the aid of tractors, companies, money, and etc. 

Right, but you are implying skin tone would drive migration. That isn't how it worked. People migrated and then over time in different environments there skin tones changed. That plus mixing with Neanderthal and Denisovan humans. 

"For example, the Neanderthal version of the skin gene POU2F3 is found in around 66 percent of East Asians, while the Neanderthal version of BNC2, which affects skin color, among other traits, is found in 70 percent of Europeans." https://news.nationalgeographic.com/news/2014/01/140129-neanderthal-genes-genetics-migration-africa-eurasian-science/

As I previously linked Half the world population, over 3.5 billion people, have a vitamin D deficiency. It isn't driving any sort of migration. If civilization fell vitamin D  would be what determines where people live. 

 

Human created those part and are the ones building those parts today. To Sensei point, why do you think the knowledge for how to do such things would be lost?

I think you may be misunderstanding the main point.

Skin tone didn't force migration, migration forced the skin tone.

Now that white people are adapted to northern latitudes, they will survive best in northern latitudes. This would force a migration in a collapsed society because they would not have access to the technology that allows them to live outside their natural habitat. Such as sunscreen, lenin clothing, sunglasses, vitamin D supplements, etc.

Vitamin D deficiency itself wouldn't kill you, but it would hinder your ability in survival. Vitamin D would be more important in a survival situation. How? Because sickness would be very important to fight off and most people would probably be using more energy than usual. Vitamin D helps us in these areas.

 

Why would knowledge be lost? It wouldn't, the resources would. Most mechanical tools would require not only knowledge but mechanisms and contraception that need to be welded and most people probably wouldn't know how or where to get these things. We would go back to traditional farming, probably using basic tools and equipment and planting heritage seeds (fruits and vegetables that are native to the land) so that it doesn't require any special soil and maintenance.

10 minutes ago, swansont said:

Not sure I understand this. It's not an hypothesis. There are definitely diseases that jumped from animals to humans after agriculture was developed (e.g. smallpox) and are only sustained by having a certain population density

https://www.ncbi.nlm.nih.gov/books/NBK114494/

But AFAIK, the diseases became less virulent because they evolved that way, and that happened faster than humans were going to evolve immunity.

Also: "collapse of civilization" has not been defined particularly well.

Collapse in civilization in the sense we are using in this thread would be an economic collapse and a collapse in the way the world works in general. And a collapse in civilization from a ww3.

[Ten oz]

6 minutes ago, Unitive_Mystic said:

I think you may be misunderstanding the main point.

Skin tone didn't force migration, migration forced the skin tone.

Now that white people are adapted to northern latitudes, they will survive best in northern latitudes. This would force a migration in a collapsed society because they would not have access to the technology that allows them to live outside their natural habitat. Such as sunscreen, lenin clothing, sunglasses, vitamin D supplements, et

I understand your point I just don't agree with it. Skin tone would not force people to migrate. The risks posed by migration, especially is a dystopian world without panes, trains, or auto, would be far greater than those posed by not having sun glasses. 

10 minutes ago, Unitive_Mystic said:

Vitamin D deficiency itself wouldn't kill you, but it would hinder your ability in survival. Vitamin D would be more important in a survival situation. How? Because sickness would be very important to fight off and most people would probably be using more energy than usual. Vitamin D helps us in these areas.

Half the worlds population is Vitiman D deficient. You are overstating the matter. In a dystopian world things like clean water and clean air would play a much bigger role in where people lived. 

14 minutes ago, Unitive_Mystic said:

Why would knowledge be lost? It wouldn't, the resources would. Most mechanical tools would require not only knowledge but mechanisms and contraception that need to be welded and most people probably wouldn't know how or where to get these things. We would go back to traditional farming, probably using basic tools and equipment and planting heritage seeds (fruits and vegetables that are native to the land) so that it doesn't require any special soil and maintenance.

Here is a video on how to make a welder from parts salvaged from an old microwave. https://www.youtube.com/watch?v=vrlvqib94xQ

 

 

[Sensei]

1 hour ago, Ten oz said:

To Sensei point, why do you think the knowledge for how to do such things would be lost?

Collapse of civilization can cause lost of knowledge. It's plausible. It happened couple times already. They're known as "dark ages", Greek dark ages, because there is no written records (or in very limited quantity) what happened in that times.. Information from ancient times, and history were stored traditionally on stones (it can survive quite a lot, but has limited capacity and quantity of copies), later replaced by paper (quite vulnerable, won't survive inappropriate environment, too large humidity etc. but can be used to heat room in cold winter..), now we have digital data stored on tapes (you can't even read tapes from '80 years the most likely), data stored on CD, DVD, Blu-ray.. They are practicability not readable without enormous amount of knowledge and/or device designed to read them, thus way far more vulnerable to be lost (by which I understand "unable to be read/understood/decoded anymore") in the case hypothetical collapse of civilization..

Store data in PDF, and imagine that you have no PDF reader anymore, and you're pretty much screwed... It's pretty hard to decode file-format, it can use different compression algorithms for different object streams (I wrote (pretty basic) PDF reader, terminology from file-format specification). It can have embedded image files (from scanner).

Language of human evolves with time. Introducing yet another way of losing data because inability to read even not compressed raw text, in in the future, unknown language.

Edited June 24, 2018 by Sensei

[Ten oz]

3 minutes ago, Sensei said:

Collapse of civilization can cause lost of knowledge. It's plausible. It happened couple times already. They're known as "dark ages", Greek dark ages, because there is no written records (or in very limited quantity) what happened in that times.. Information from ancient times, and history were stored traditionally on stones (it can survive quite a lot, but has limited capacity and quantity of copies), later replaced by paper (quite vulnerable, won't survive inappropriate environment, too large humidity etc.), now we have digital data stored on tapes (you can't even read tapes from '80 years the most likely), data stored on CD, DVD, Blu-ray.. They are practicability not readable without enormous amount of knowledge and/or device designed to read them, thus way far more vulnerable to be lost (by which I understand "unable to be read/understood/decoded anymore") in the case hypothetical collapse of civilization..

Store data in PDF, and imagine that you have no PDF reader anymore, and you're pretty much screwed... It's pretty hard to decode file-format, it can use different compression algorithms for different parts of "streams". It can have embedded image files (from scanner).

Language of human evolves with time. Introducing yet another way of losing data because inability to read even not compressed raw text, in in the future, unknown language.

True, but information wasn't as well distributed then. Burning down a single library wouldn't set culture back any today. Plus far more people are literate. Literacy for thousands of years was a skill only elites had. Not just that but instructions are so good nowadays a 5yrs kid could assemble Ikea furniture just following along with the pictures. 

The scene the OP seems to be painting would be better suited for scenario where people were standard on a massive never before inhabited island without any tools or access to record information. 

[swansont]

2 hours ago, Unitive_Mystic said:

Collapse in civilization in the sense we are using in this thread would be an economic collapse and a collapse in the way the world works in general. And a collapse in civilization from a ww3.

Economic collapse would not necessarily result in a loss of technology. And WW3 would likely be a very different scenario.

Even with a loss of technology, though, there are many levels of technology. It's still very vaguely defined.

[Unitive_Mystic]

1 hour ago, Ten oz said:

I understand your point I just don't agree with it. Skin tone would not force people to migrate. The risks posed by migration, especially is a dystopian world without panes, trains, or auto, would be far greater than those posed by not having sun glasses. 

Half the worlds population is Vitiman D deficient. You are overstating the matter. In a dystopian world things like clean water and clean air would play a much bigger role in where people lived. 

Here is a video on how to make a welder from parts salvaged from an old microwave. https://www.youtube.com/watch?v=vrlvqib94xQ

 

 

I think you have been playing a little to much fallout lol.

Half of the world's population is vitamin D deficient, but they have doctors, vitamin supplements, and antibiotics.

In the beginning people will have cars. And that is how they would relocate. And people would only relocate if it would be necessary. Which in alot of situations it would.

People wouldn't use sunscreen, sunglasses, lenin clothing and skin cancer treatment and vitamin supplaments if they didn't have to.

I think that you might think that people with white skin living in southern lattitude would be fine without modern conveniences. History would say otherwise.