South Scadrial Theory

[cometaryorbit]

TLDR: The Southern Scadrians weren't completely shielded from ash during the Final Empire era; wearing masks was originally protection against ash and became purely cultural after the Catacendre/Ice Death. Sazed didn't know they weren't default human at the time of his Ascension since their changes were natural not due to TLR at the Well.

So we know that TLR didn't genetically alter the Southerners to survive the Ashworld. But at the end of HOA we see that the sun intensity without ash is far too much for any conventional life to survive - trees are bursting into flame.

The solar system chart in Arcanum Unbounded also shows a huge difference in orbit, maybe something like the TLR-era orbit being half the distance of the original/Harmony-era orbit. So solar intensity is probably at least 3x Earth's (1/2 distance would mean 4x intensity).

So the Southern Scadrians were originally unaltered. Yet they now freeze to death in conditions that others would consider "only mildly cold". And they have higher than human normal body temperatures.

So why did they change, if it wasn't Rashek's work? Evolution perhaps... but for evolution to work the conditions have to be survivable for at least some of the population. Trees-bursting-into-flame conditions would just kill everyone, no evolution possible.

So maybe the South pole was more reasonable. Still very hot... but polar latitude plus high elevation plus some ash cover...

Sure the ash concentrated at the north magnetic pole (Luthadel) but that doesn't mean zero ash elsewhere.

But the Southerners weren't modified to breathe ash... thus the masks. Probably they were simply cloth masks during the ash era - diverging into various cultural forms (Allik says the different Southern nations have different customs in regards to masks) and becoming more permanent and ornate things after their practical use was gone.

Sazed probably restored the South to a mild climate... but since their high temperature adaptations were natural, not done by Preservation's power, he didn't see them with the "memory of the power " and thus didn't know to reverse them.

(In RL, I don't think you could get major changes to something as fundamental as body temperature in a mere thousand years- 30 or 40 generations. But it's not unthinkable- there is individual variation in human body temperature, not everyone is exactly 98.6 F, so evolution could act on it. I just don't think it would be this dramatic- especially since the human brain has trouble with higher temperatures).

 

[Frustration]

Evolution in the Cosmere is really fast.

Spoiler

Questioner

Do the Purelakers get pruney feet because of the water? If not, is it because they have special feet or does it have to do with the magic fish?

Brandon Sanderson

They have adapted over time and they do not have magic feet. They have special feet, but they have adapted over time to the situation. Now, let's make the note that most natural selection does not work on the timescale of the cosmere and so there probably have to be some magical foundations for this. The fact that everyone on Roshar is Invested with a bit of Investiture more than average is going to push people over time in a way. Kind of the rationale I give myself on this is because Intent and these sorts of things are so important cosmerelogically that we get evolution on a faster scale in most of the cosmere. And so you can see this just by adaptations that have happened since the history of Roshar itself and the arrival of humans on Roshar and things like that.

YouTube Livestream 9 (May 28, 2020)

 

[cometaryorbit]

Huh! "We get evolution on a faster scale in most of the cosmere"... ok that makes this make way more sense! Thank you.

[Treamayne]

13 hours ago, cometaryorbit said:

(In RL, I don't think you could get major changes to something as fundamental as body temperature in a mere thousand years- 30 or 40 generations. But it's not unthinkable- there is individual variation in human body temperature, not everyone is exactly 98.6 F, so evolution could act on it. I just don't think it would be this dramatic- especially since the human brain has trouble with higher temperatures).

Keep in mind that cold and heat injuries are not emperically vast. IRL Human normal is ~37C (98.6F) - but Hypothermia is defined as a core body temperature of 35C (95F) and Heat Stroke is a core body temp of 40C (104F). So the range of normal human temperatures is only 5 degrees C (9 degrees F). Even an evolutionary shift in core body temperature of 1-2 degrees would likely result in a distinct shift of survivable environments. 

13 hours ago, Frustration said:

Evolution in the Cosmere is really fast.

  Hide contents

Questioner

Do the Purelakers get pruney feet because of the water? If not, is it because they have special feet or does it have to do with the magic fish?

Brandon Sanderson

They have adapted over time and they do not have magic feet. They have special feet, but they have adapted over time to the situation. Now, let's make the note that most natural selection does not work on the timescale of the cosmere and so there probably have to be some magical foundations for this. The fact that everyone on Roshar is Invested with a bit of Investiture more than average is going to push people over time in a way. Kind of the rationale I give myself on this is because Intent and these sorts of things are so important cosmerelogically that we get evolution on a faster scale in most of the cosmere. And so you can see this just by adaptations that have happened since the history of Roshar itself and the arrival of humans on Roshar and things like that.

YouTube Livestream 9 (May 28, 2020)

 

Thanks

14 hours ago, cometaryorbit said:

And they have higher than human normal body temperatures.

Also, do we have confirmation that SoScads have a "higher" core body temp? That seems counter-intuitive - a  higher core temp would be an adaptation to cold environments (and it would be much harder to get chilled in "normal" weather), while a lower core temp would be an adaptation to hot environments (and make it much easier to get chilled in "normal" weather.

For example the Bactrian Camel's natural core body temp of 36.5C allows it to tolerate body temperature fluctuations from 34-40C without experiencing Hypothermia or Heat Stroke.

[cometaryorbit]

On 7/8/2022 at 1:09 PM, Treamayne said:

Also, do we have confirmation that SoScads have a "higher" core body temp? That seems counter-intuitive - a  higher core temp would be an adaptation to cold environments (and it would be much harder to get chilled in "normal" weather), while a lower core temp would be an adaptation to hot environments (and make it much easier to get chilled in "normal" weather.

For example the Bactrian Camel's natural core body temp of 36.5C allows it to tolerate body temperature fluctuations from 34-40C without experiencing Hypothermia or Heat Stroke.

I am pretty sure the MAG said they had lower body temp and there is a WOB correcting that.

I think it's higher because they can still lose heat to outside (heat will flow body -> environment) at a higher ambient temperature.

I am not sure you can directly compare species with very different body types like humans and camels; there are a lot of factors in this sort of thing, warm-blooded bodies actively maintain temperature (blood circulation changes, sweating/panting, shivering etc.) and these things can vary between species.

Also body size and shape (surface area to volume ratio) matter: larger or bulkier things lose heat slower, smaller or less bulky things faster. There's a known trend (Bergmann's rule) that widespread warm blooded animals tend to be larger in colder parts of their range (wolves are huge in Alaska and Siberia but tiny in India, whitetail deer are huge in Minnesota and Canada but tiny in the Florida Keys).

In at least some cases colder body temp is better for colder environments: some small birds specifically lower their core temp to survive cold nights in 'torpor' (eg hummingbirds in the high Andes where nights are cold). At higher body temperature they would starve themselves to death overnight.

On 7/8/2022 at 1:09 PM, Treamayne said:

Keep in mind that cold and heat injuries are not emperically vast. IRL Human normal is ~37C (98.6F) - but Hypothermia is defined as a core body temperature of 35C (95F) and Heat Stroke is a core body temp of 40C (104F). So the range of normal human temperatures is only 5 degrees C (9 degrees F). Even an evolutionary shift in core body temperature of 1-2 degrees would likely result in a distinct shift of survivable environments.

I agree there, but it still seems significantly larger than what would happen in a thousand years in RL - we have groups of  people who have lived in very different temperatures for longer than that and while there is some adaptation it's nothing this dramatic.

Edited July 11, 2022 by cometaryorbit

[Frustration]

On 7/8/2022 at 2:09 PM, Treamayne said:

Keep in mind that cold and heat injuries are not emperically vast. IRL Human normal is ~37C (98.6F) - but Hypothermia is defined as a core body temperature of 35C (95F) and Heat Stroke is a core body temp of 40C (104F). So the range of normal human temperatures is only 5 degrees C (9 degrees F). Even an evolutionary shift in core body temperature of 1-2 degrees would likely result in a distinct shift of survivable environments. 

Our tolerable limits are pretty big, even without changing clothes we can handle pretty dramatic temperature shifts. I find it difficult to believe that only a 1-2 degree shift is enough that they can freeze to death in only moderate cold.

[cometaryorbit]

I think the Southern Scadrians don't just have a higher core temp they are probably closer to "cold blooded" than standard humans.  I believe someone pointed out that warm clothing would work better for them than it seems to if they had regular metabolisms.