Distance from the equator and human evolution

[bluemoonKY]

I was pondering human evolution on different continents recently and some thoughts occurred to me:
1# the distance a region is from the equator determines the temperature of a climate all over the Earth
2# humans have probably been in regions of varying distances from the Equator long enough for this to have evolutionary effects
3# Living in colder climates would select for any number of different traits than living in warmer climates
4# Therefore, people whose ancestors lived in colder climates might have adaptations different from people whose ancestors tended to live in warmer climates across the Earth

I have never once in my life heard or read anyone mentioned my thought 4#.

I will call the regions close to the equator tropical areas. Tropical areas include sub-Saharan Africa, the Caribbean Islands in the Americas, Central America , Mexico, Hawaii, the Philippines, the Polynesians Islands, New Zealand, and Australia.

To my knowledge, there are no areas of Earth that were populated for eons that were cold because they were far SOUTH of the equator. To my knowledge, the only areas of Earth that were populated for eons that were cold because they were far from the equator are areas far north of the equator. Therefore, I will call the areas that were cold because they were far from the equator "northern latitude areas."

Northern latitude areas include Europe, northern Asia such as Japan, China, North Korea and South Korea, Hong Kong, and the Canada and Alaska, and the northern part of the United States of America.

The significance of all this is that there might be traits that northern latitude area people hold different than tropical people ALL OVER THE WORLD.

Wouldn't people who lived in northern latitude areas for eons be selected to have the abilities to do all these things all well before winter starts: make well insulated shelters, stockpile fuel for fires such as firewood and kindling, make well insulated warm clothing to survive winter, and stockpile adequate food for the winter? I would think that this would hold true for northern latitude areas all over the world. It's something Europeans would be selected for just as much as, say, the American Eskimos, wouldn't it? Tropical people wouldn't have to make well insulated shelters and stockpile food and fuel for fires to stay warm.

I have never once in my life heard or read someone mention such as ideas as these that have occurred to me. I find it strange that I have never heard or read someone mention this. Perhaps anthropologists are well familiar with such ideas though. I'm not an anthropologist.

If my ideas of the significance of distance from the equator shaping evolutions of humans worldwide are wrong, please tell me how and why the distance from the equator would not select for the traits that I mentioned. Perhaps humans have not been in regions far from the equator long enough to have evolutionary effects. Perhaps that is what I am missing.

What traits would people from tropical climates be selected for that people from northern latitude areas would not be selected for?

 

[Bystander]

https://en.wikipedia.org/wiki/Jared_Diamond

 

[bluemoonKY]

https://en.wikipedia.org/wiki/Jared_Diamond

I read about Jared Diamond on Wikipedia. I read descriptions of all four of his books: 1# The Third Chimpanzee, 2#Guns, Germs, and Steel, 3# Collapse, and 4# The World Until Yesterday. I didn't see anything relating to my ideas about how distance from the equator could have affected the evolution of humans.

Why did you post a link to Jared Diamond? Did Jared Diamond write about my ideas about distance from the equator affecting evolution in an article in a peer reviewed scientific journal (as opposed to in a book)? If so, what did Jared Diamond say about this issue?

 

[Ygggdrasil]

The classic example is the evolution of skin color, which is stratified quite well by latitude:
http://scienceline.org/2012/02/the-skin-were-in/
https://en.wikipedia.org/wiki/Human_skin_color#Evolution_of_skin_color
http://www.sciencemag.org/news/2017/10/new-gene-variants-reveal-evolution-human-skin-color

 

[russ_watters]

Wouldn't people who lived in northern latitude areas for eons be selected to have the abilities to do all these things all well before winter starts: make well insulated shelters, stockpile fuel for fires such as firewood and kindling, make well insulated warm clothing to survive winter, and stockpile adequate food for the winter? I would think that this would hold true for northern latitude areas all over the world. It's something Europeans would be selected for just as much as, say, the American Eskimos, wouldn't it? Tropical people wouldn't have to make well insulated shelters and stockpile food and fuel for fires to stay warm...

If my ideas of the significance of distance from the equator shaping evolutions of humans worldwide are wrong, please tell me how and why the distance from the equator would not select for the traits that I mentioned...

What traits would people from tropical climates be selected for that people from northern latitude areas would not be selected for?

As mentioned, environmental factors affecting human evolution is a well known phenomena. But what you listed are not physical traits, they are learned skills. They are not passed down genetically, so they aren't related to biological evolution - at least not directly/easily/quickly.

 

[bluemoonKY]

As mentioned, environmental factors affecting human evolution is a well known phenomena. But what you listed are not physical traits, they are learned skills. They are not passed down genetically, so they aren't related to biological evolution - at least not directly/easily/quickly.

If environmental factors affecting human evolution is a well known phenomena, it sure is not wrote or discussed about much. When I was in public school, I don't think any of my teachers mentioned it even once.

I agree that the skills I mentioned that one much have to survive in the colder climates are not physical traits. They are learned skills. You say that "the skills are not passed down genetically, so they aren't related to biological evolution- at least not directly/easily/quickly." Hold on. The skills can not be passed down genetically, and yet the need to possesses these skills can still cause differential evolution of certain groups due to climate differences due to distance from the equator in certain regions. The need to possesses the skills I mentioned in northern latitude regions could cause differential evolution in the human brains in northern latitude peoples than in tropical peoples. I'm not saying that people in northern latitude regions evolved the skills I mentioned. I am saying that perhaps people in northern latitude regions evolved brains congenial to learning the skills i mentioned and evolved brains to have the foresight to perform the skills I mentioned.

In other words, wouldn't the colder climates of northern latitude regions select for people to evolve brains congenial to learning the skills and select for people to evolve brains with the foresight to know to perform such skills long in advance of winter?

 

[bluemoonKY]

The classic example is the evolution of skin color, which is stratified quite well by latitude:
http://scienceline.org/2012/02/the-skin-were-in/
https://en.wikipedia.org/wiki/Human_skin_color#Evolution_of_skin_color
http://www.sciencemag.org/news/2017/10/new-gene-variants-reveal-evolution-human-skin-color

I knew about skin color. People in northern latitude regions have lighter colored skin because they receive less concentrated sunlight than tropical peoples. Therefore, people in northern latitude regions evolved lighter skin to absorb more sunlight to get sufficient vitamin D. That is actually the one and only example I have heard someone say about northern latitude regions causing differential evolution around the world. One of my professors mentioned that once when I was in college.

Therefore, you are totally right that northern latitude regions cause less concentrated sunlight which in turn causes differential evolution of skin color. However, I did not mention skin color just because I was more focused on temperature differences causing differential evolution as opposed to sunlight differences.

 

[russ_watters]

If environmental factors affecting human evolution is a well known phenomena, it sure is not wrote or discussed about much. When I was in public school, I don't think any of my teachers mentioned it even once.

I don't know your age/background, but I'm pretty sure the origin of skin color in particular was taught to me in school in science class and possibly also social studies class. I'm 41 and live in the northeast US. Here's a couple of k-12 learning resource sites with lesson plan materials on the subject, which implies that it is still often taught in school:
http://sciencenetlinks.com/lessons/variation-in-human-skin-color/
http://www.hhmi.org/biointeractive/biology-skin-color

And hopefully this won't lead to political discussion, but given the climate over the last decade or two, I would think that discussion of this important topic should have only gotten stronger.

I agree that the skills I mentioned that one much have to survive in the colder climates are not physical traits. They are learned skills. You say that "the skills are not passed down genetically, so they aren't related to biological evolution- at least not directly/easily/quickly." Hold on. The skills can not be passed down genetically, and yet the need to possesses these skills can still cause differential evolution of certain groups due to climate differences due to distance from the equator in certain regions. The need to possesses the skills I mentioned in northern latitude regions could cause differential evolution in the human brains in northern latitude peoples than in tropical peoples. I'm not saying that people in northern latitude regions evolved the skills I mentioned. I am saying that perhaps people in northern latitude regions evolved brains congenial to learning the skills i mentioned and evolved brains to have the foresight to perform the skills I mentioned.

So, at the very least you must see a timing problem there, as I mentioned: before the skills can affect the brain's evolution, the skills themselves first have to develop, consistently and over a very long span of time. So the brain's evolution would take longer than a physical trait evolution due to the additional step.

Next, the brain is in many ways a general-purpose computer and doesn't have difficulty being trained to do different tasks. You have not suggested a way in which the brain could evolve to favor one skill over another.

 

[bluemoonKY]

I don't know your age/background, but I'm pretty sure the origin of skin color in particular was taught to me in school in science class and possibly also social studies class. I'm 41 and live in the northeast US. Here's a couple of k-12 learning resource sites with lesson plan materials on the subject, which implies that it is still often taught in school:

I'm 37, and I never witnessed any teachers teaching the evolution of skin color until I was in college.

And hopefully this won't lead to political discussion, but given the climate over the last decade or two, I would think that discussion of this important topic should have only gotten stronger.

It seems that the discussion of it did not get stronger. In fact, I never have witnessed a discussion of it except in regards to skin color. In fact, nobody taught me any of this except for how differential sunlight causes differential skin color. That cold weather regions could cause differential evolution in humans due to temperature differences is just something I deduced.

So, at the very least you must see a timing problem there, as I mentioned: before the skills can affect the brain's evolution, the skills themselves first have to develop, consistently and over a very long span of time.

The skills don't affect the brain's evolution. I am saying that perhaps the climate affects the brain's evolution due to the need to possesses such skills.

So the brain's evolution would take longer than a physical trait evolution due to the additional step.

I am agnostic on which would take longer to develop: the brain's evolution or physical trait evolution. However, your statement that "the additional step" would cause the brain's evolution to take longer than evolution of a physical trait is erroneous since it relies on a false premise. The false premise is that the skills can affect the brain's evolution.

Next, the brain is in many ways a general-purpose computer and doesn't have difficulty being trained to do different tasks. You have not suggested a way in which the brain could evolve to favor one skill over another.

Then I will suggest a way in which the brain could evolve to favor learning how to perform such skills and in which the brain could evolve to have the foresight to perform such skills long in advance of winter (which is my argument rather than that the brain could evolve to favor one skill over another). In northern latitude climates, people whose brains had the foresight to build dwellings with chimneys or other smoke ventilation systems such as teepees and who also had the foresight to stockpile firewood and non-perishable food for the winter would not die of exposure or starvation in the winter. And, in northern latitude areas, people whose brains did not have the foresight to build dwellings with chimneys or other smoke ventilation systems such as teepees or who did not have the foresight to stock such dwellings with adequate firewood and nonperishable food would die of exposure or starvation during the winter. Therefore, over the eons, people in northern latitude regions who had the foresight to do the skills would survive to reproduce, and people who did not have the foresight would die. Therefore, over the eons, people in northern latitude regions would tend to have the foresight to perform the skills needed to survive the winters in northern latitude regions, while tropical people would be less likely to have the foresight that the northern latitude people have since tropical people were never selected to have the foresight to perform the tasks needed to survive the winters in northern latitude regions.

 

[russ_watters]

The skills don't affect the brain's evolution. I am saying that perhaps the climate affects the brain's evolution due to the need to possesses such skills.

I'm not following - you seem to be describing evolution backwards. How does the brain know it needs to evolve to support certain skills until the skills themselves are established? For example, if you need finer motor skills to knit a sweater in a cold climate, how does your brain know you need fine motor skills to develop the ability before the skill is developed? The way evolution generally works is that a particular skill is being used and an animal that is good at it survives (or breeds) and an animal that is bad at it dies (or doesn't reproduce). The success or failure in the use of the skill is what drives the evolution, not the brain somehow knowing the skill is needed and creating the skill (or ability to support the skill) from scratch.
See: https://brainconnection.brainhq.com/2017/09/03/the-evolution-of-language/

The false premise is that the skills can affect the brain's evolution.

Skills can affect the brain's evolution. The above article is an example. Long article, but here's a key quote:
"It seems likely that language was built on top of an existing cognitive structure. However, given the importance of language to human social interaction, including reproduction, it also seems likely that selective pressures would prefer genetic modifications that improved language capabilities. "

As I said in my previous post, the brain is in large part a flexible-programming computer. But there are IO modules and related processing that are task-specific (eyes, ears). Langauge likely started by utilizing pre-existing systems, per the quote above. But then after the skill was created, it would then have the ability to steer the evolution. Either way, what is not suggested is that the environment somehow created in us a need to speak, which then drove evolution to create language processing capabilities before we started using them.

Evolution is a force and force cannot be applied to something that doesn't exist.

Then I will suggest a way in which the brain could evolve to favor learning how to perform such skills and in which the brain could evolve to have the foresight to perform such skills long in advance of winter (which is my argument rather than that the brain could evolve to favor one skill over another). In northern latitude climates, people whose brains had the foresight to build dwellings...

We aren't psychic: we can't anticipate a need and generate an adaptation prior to the need arising. That isn't how evolution works and isn't how our brains work. Evolution happens after the force is applied, not before. We only predict the next winter because we saw or were told about the last winter. We do not have pre-programmed calendars in our brains.

 

[bluemoonKY]

I'm not following - you seem to be describing evolution backwards. How does the brain know it needs to evolve to support certain skills until the skills themselves are established?

You are misinterpreting me.

Evolution happens over many, many generations. The brains of prehistoric peoples did not know that they needed to evolve anything whatsoever. Evolution just happened.

For example, if you need finer motor skills to knit a sweater in a cold climate, how does your brain know you need fine motor skills to develop the ability before the skill is developed?

Evolution by natural selection is an unconscious process that just happens.

The way evolution generally works is that a particular skill is being used and an animal that is good at it survives (or breeds) and an animal that is bad at it dies (or doesn't reproduce). The success or failure in the use of the skill is what drives the evolution, not the brain somehow knowing the skill is needed and creating the skill (or ability to support the skill) from scratch.

I will rephrase my position: Here is how the climate of northern latitude areas could cause northern latitude people to evolve the foresight to prepare for winter. Foresight was used by prehistoric northern latitude people in northern latitude areas and northern latitude people that had a lot of foresight to prepare for winter survived (or breeded) and northern latitude people that did not have foresight died (or did not reproduce). The success or failure in the use of the skill is what drives the evolution, not the brain somehow knowing that it needs foresight and creating the foresight from scratch.

I agree 100% with you on how evolution generally works. I even described the exact same thing in the last paragraph of my last post.

I will post it again:
"In northern latitude climates, people whose brains had the foresight to build dwellings with chimneys or other smoke ventilation systems such as teepees and who also had the foresight to stockpile firewood and non-perishable food for the winter would not die of exposure or starvation in the winter. And, in northern latitude areas, people whose brains did not have the foresight to build dwellings with chimneys or other smoke ventilation systems such as teepees or who did not have the foresight to stock such dwellings with adequate firewood and nonperishable food would die of exposure or starvation during the winter. Therefore, over the eons, people in northern latitude regions who had the foresight to do the skills would survive to reproduce, and people who did not have the foresight would die. Therefore, over the eons, people in northern latitude regions would tend to have the foresight to perform the skills needed to survive the winters in northern latitude regions, while tropical people would be less likely to have the foresight that the northern latitude people have since tropical people were never selected to have the foresight to perform the tasks needed to survive the winters in northern latitude regions."

End of quote from my previous post
___________________________________________________________________________________________________________

I am astounded that you think that my position is that the human brain evolved by knowing that it needed to evolve certain skills until the skills themselves are established.

Evolution is a force and force cannot be applied to something that doesn't exist.

We aren't psychic: we can't anticipate a need and generate an adaptation prior to the need arising. That isn't how evolution works and isn't how our brains work. Evolution happens after the force is applied, not before. We only predict the next winter because we saw or were told about the last winter. We do not have pre-programmed calendars in our brains.

I agree 100%. I'm astounded at how you interpreted my previous post.

Evolution happens after the force is applied, not before. The force is cold winters. We only predict the next winter because we saw or were told about the last winter. We do not have preprogrammed calendars in our brains.

My position on how evolution generally works is the same as yours.

Edit: I re-read my previous post to see why you interpreted my position on evolution the way you did. I still cannot figure it out. Look at the sentence I highlighted in red on this post! How could you misinterpret me like that? I am baffled.

 

[Mark44]

To my knowledge, there are no areas of Earth that were populated for eons that were cold because they were far SOUTH of the equator. To my knowledge, the only areas of Earth that were populated for eons that were cold because they were far from the equator are areas far north of the equator.

In one of the books by Jared Diamond that you listed below, "Guns, Germs, and Steel," he lays out the current thinking about how the continents were populated. The prevailing opinion about the origin and spread of homo sapiens is that we started from somewhere in northwest Africa, and spread out in basically all directions from there. According to this theory, some people slowly spread out in Africa and Europe, and later moved into Asia, eventually populating SE Asia and the Malay Peninsula, and from there the islands of Indonesia, New Guinea, and Australia. Some of the last areas to be populated were North America on down to South America.

Therefore, I will call the areas that were cold because they were far from the equator "northern latitude areas."

I was going to say, "Well, duh," but I won't. What about the areas that aren't that far north, but are cold because they are considerably above sea level? The three highest towns in the world are between 15,000' to nearly 17,000 feet, in the Himalayas and Andes mountains. They are between latitudes of about 15° S. to about 34° N., so they could hardly be called northern latitude locations. You can bet that these places are very cold in the winter, and not all that warm in the summer.

read about Jared Diamond on Wikipedia. I read descriptions of all four of his books: 1# The Third Chimpanzee, 2#Guns, Germs, and Steel, 3# Collapse, and 4# The World Until Yesterday. I didn't see anything relating to my ideas about how distance from the equator could have affected the evolution of humans.

I've read only one of his books, "Guns, Germs, and Steel," and found it very interesting. I would strongly recommend it.

I'm not sure what your aim is in this thread. Maybe I'm mistaken, but it seems like you're trying to posit that people who came from the northern latitudes are somehow superior to those from more tropical areas. I hope that's not where you're trying to go.

 

[Drakkith]

I will rephrase my position: Here is how the climate of northern latitude areas could cause northern latitude people to evolve the foresight to prepare for winter. Foresight was used by prehistoric northern latitude people in northern latitude areas and northern latitude people that had a lot of foresight to prepare for winter survived (or breeded) and northern latitude people that did not have foresight died (or did not reproduce). The success or failure in the use of the skill is what drives the evolution, not the brain somehow knowing that it needs foresight and creating the foresight from scratch.

Evolution didn't directly give us the skills needed to survive winter. Instead, it had already given us a highly adaptable brain that was able to respond to the changing environment without requiring the introduction of new traits via evolution. Also note that complex skills are not things that can be passed down through evolution. Only very basic skills and reflexes are hard-wired into us. Skills such as foresight, the ability to construct shelter and clothes, etc are learned. Evolution can affect our ability to learn these skills, but it can't hard-wire them into our brains.

 

[bluemoonKY]

In one of the books by Jared Diamond that you listed below, "Guns, Germs, and Steel," he lays out the current thinking about how the continents were populated. The prevailing opinion about the origin and spread of homo sapiens is that we started from somewhere in northwest Africa, and spread out in basically all directions from there. According to this theory, some people slowly spread out in Africa and Europe, and later moved into Asia, eventually populating SE Asia and the Malay Peninsula, and from there the islands of Indonesia, New Guinea, and Australia. Some of the last areas to be populated were North America on down to South America.

Although I have never read Guns, Germs, and Steel, Diamond's understanding of the origin and spread of homo sapiens (as you describe it, anyway) is 100% consistent with my understanding of the origin and spread of homo sapiens.

I was going to say, "Well, duh," but I won't. What about the areas that aren't that far north, but are cold because they are considerably above sea level? The three highest towns in the world are between 15,000' to nearly 17,000 feet, in the Himalayas and Andes mountains. They are between latitudes of about 15° S. to about 34° N., so they could hardly be called northern latitude locations. You can bet that these places are very cold in the winter, and not all that warm in the summer.

This is just nitpicking. I know that mountains of extremely high altitude that are close to the equator are cold despite being close to the equator. That doesn't really change my thesis in any way. Furthermore, it's obvious that that is quite irrelevant to my thesis. Why did you bring it up?

I've read only one of his books, "Guns, Germs, and Steel," and found it very interesting. I would strongly recommend it.

I read the description of GUns, Germs, and Steel. It's thesis is not germane to this thread.

I'm not sure what your aim is in this thread. Maybe I'm mistaken, but it seems like you're trying to posit that people who came from the northern latitudes are somehow superior to those from more tropical areas. I hope that's not where you're trying to go.

My aim in this thread is to get feedback on my theory.

I never said that people who came from northern latitude areas are superior to those from more tropical areas. How dare you make such a monstrous accusation against me!

 

[jedishrfu]

Closed for moderation...

 

[Mark44]

My aim in this thread is to get feedback on my theory.

Check the forum rules -- personal theories are not allowed.

Thread will remain closed.