3 ms·
Humans haven't had multiple generations of selective breeding to select for particular cognitive traits. We have, however, had:
• Sunburn / vitamin D deficienc
Humans haven't had multiple generations of selective breeding to select for particular cognitive traits. We have, however, had:
• Sunburn / vitamin D deficiency
• Oxygen deprivation at high altitudes
• Free diving
which have had obvious effects on certain human populations. But mentally, we're all pretty much just human, same as any other; variation is massive, yes, but it can be pretty big between siblings. Seeing “sheep dog breeds have a herding instinct” doesn't tell you much about humans.
When people try to argue a “genetic basis” for a particular trait, they're usually just trying to justify racism.
Exactly.
Different populations of humans vary wildly by almost every physical trait, such as height, build, bone structure, skin, hair type, eye color, muscle fiber.
But when it comes to the brain, we are all exactly the same.
Muscle fiber variations across humans are pretty small. They're really only very noticeable as far as the extremes, or in quite small populations.
Similarly, hair types are barely different. But to tell you a story, the village my ancestors lived in for centuries had people with smooth blond hair and people like me with extremely stiff black hair. Same for eye color. Anyways, I digress, these are generally single-gene variations which is why you will find most of the variation in most populations.
Height and build is an interesting one. For most of history heights were very similar across populations. Actually, the only exception we know of were Anglo-Saxon settlers, and some peoples in South-East Asia.
This suggests that people even in extremely remote places had incredibly similar evolutionary pressures that led to almost identical heights. But nowadays, the specificities of the impact on a changing diet are different [https://www.tandfonline.com/doi/abs/10.1080/20780389.2012.657489 https://www.tandfonline.com/doi/abs/10.1080/20780389.2012.65...].
Skin is really the biggest one, because Vitamin-D deficiency and skin cancer are huge evolutionary pressures. But as we've seen, otherwise it's pretty clear humans evolved in broadly similar environments and found very similar tradeoffs. This is especially true for intelligence where the biggest load for intelligence was social interactions, and where social structures are very similar.
I know people don't want to admit to genetic impacts on cognition but there have been pressures over many generations for these traits and those pressures have been different all over the world.
Take the example of a genetic lineage living in a jungle where it is necessary to know the difference, availability, dietary qualities, medicinal aspects of thousands of plants. Not to mention predatory dangers, snake dangers, environmental dangers, etc.
In this case, the individual with high aptitudes for memorization, categorization and pattern matching would survive at a substantially higher rate than those with lower aptitudes. Remember, a small band does not have the resources to support low producing members so they would not be artificially perpetuated.
No; the individual with high aptitudes for memorisation, categorisation and pattern-matching would become the local healing expert, likely apprenticed to whoever was best at it before. Everyone else would focus primarily on the predatory and environmental dangers, plus their own specialisms (and, you know, everything else).
Remember: we live in a society. So did our ancestors. Intelligence is a pretty general skill; all sorts of different selection pressures push it up, not least of all interpersonal politics; in a band of well-to-do humans who have elders, long-term survival is probably common enough that the dating scene has a higher impact on reproductive fitness than raw survival skill.
>in a band of well-to-do humans...
Very sincere question.
From my understanding, most bands were not well to do and specialization wasn't so common until recent history ( agrarian ages ). So in these instances wouldn't cognitive abilities be more generally valuable?
Also, if you were a gathering type and needed to survive for a week away from your group the cognitive skills to recognize resources, weather, threats, etc as well as navigate back to your group would require a certain aptitude. Those without the aptitude would simply not return. Correct?
> Oxygen deprivation at high altitudes
This is actually three examples in one. Tibetans, Andeans, and Ethiopians each have their own unique version of this adaptation.
> From my understanding, most bands were not well to do and specialization wasn't so common until recent history ( agrarian ages ).
I don't know about ages, but in recent non-agrarian cultures (e.g. Buffalo-hunters in North America) there were often medical specialists. But if we're getting pedantic, individualism would also have been a lot lower; people tend to look out for each other when they live together. Your “memorisation skills improve survival” argument doesn't work all that well when the memorisation required is well within the ability of almost all modern humans, if that's what their lives are centred around. (How many pieces of trivia does the average person know about celebrities? And that's not even deliberately-learnt knowledge.)
> Those without the aptitude would simply not return. Correct?
Those without the aptitude wouldn't go on such an expedition in the first place, if they had any sense in them.
You're trying hard to think of hypothetical scenarios where your hypothesis is true, and not hypothetical scenarios where your hypothesis is false. If I get to come up with loads of situations where my theory is true, I can justify any theory to myself. That's why scientists care so much about falsification.
Is there evidence to support this, or is it just Internet speculation? For example, do we know what traits would favor someone in a jungle? Have you lived in a jungle or researched the question?
Do we know how evolution works? One thing I believe I understand is that evolution takes far longer than people imagine. A few centuries is nothing. Humans have been in their current evolutionary form for around 200,000 years. Adaptations are not evolution, and our genetics change and adapt during our lifetimes. My children will not be genetically better at typing than the original homo sapiens. Think of that: You are not genetically smarter than humans of 200,000 years ago; someone then is just as able to be a scientist as you are. All of our advantages are from other factors.
Another thing I've learned is that claims need evidence; that's what separates the wheat from the infinite chaff, the science from the witchcraft. The parent comment would require evidence to qualify for even a high school essay.
> Do we know how evolution works? One thing I believe I understand is that evolution takes far longer than people imagine. A few centuries is nothing. Humans have been in their current evolutionary form for around 200,000 years.
Evolution is a continuum. There is no "current form", it is constantly changing with every new human that is born.
> Adaptations are not evolution, and our genetics change and adapt during our lifetimes. My children will not be genetically better at typing than the original homo sapiens.
Your offspring will have different attributes than you. This is evolution.
> Think of that: You are not genetically smarter than humans of 200,000 years ago; someone then is just as able to be a scientist as you are. All of our advantages are from other factors.
This is conjecture. You don't know that modern humans aren't "genetically smarter" than those from 200,000 years ago. Neanderthals existed up until around 40,000 years ago, all the while interbreeding with other humans.
> Another thing I've learned is that claims need evidence; that's what separates the wheat from the infinite chaff, the science from the witchcraft. The parent comment would require evidence to qualify for even a high school essay.
Meanwhile, you provided zero evidence.
> Evolution is a continuum. There is no "current form", it is constantly changing with every new human that is born.
It's an inspiring philosophical concept, but it's like saying 'the world changes with every breath you take'.
> Your offspring will have different attributes than you. This is evolution.
They have different attributes for many reasons that have nothing to do with evolution (and are not hereditary). And any real evolutionary changes are so small that they practically don't exist.
> This is conjecture. You don't know that modern humans aren't "genetically smarter" than those from 200,000 years ago.
It's not conjecture; it's based on evidence: I can't cite the exact science off the top of my head, but humans have been biologically the same for around 200,000 years.
> Meanwhile, you provided zero evidence.
You are the one making the claims; you need to provide the evidence. I'm not going around the Internet finding citations for everyone.
>You are the one making the claims; you need to provide the evidence.
There is evidence that human evolution is actually speeding up since the dawn of agriculture.
"...scientists can study the changes in the frequency of an allele occurring in a tiny subset of the population over a single lifetime, the shortest meaningful time scale in evolution"[0]
>humans have been biologically the same for around 200,000 years.
Human evolution did not abruptly stop. It has continued. [1]
>any real evolutionary changes are so small that they practically don't exist
Evolution can occur in tiny changes and large changes. Most changes are adaptive evolution which changes the species over time. [2]
[0] https://en.wikipedia.org/wiki/Recent_human_evolution https://en.wikipedia.org/wiki/Recent_human_evolution
[1] https://www.scientificamerican.com/article/culture-speeds-up-human-evolution/ https://www.scientificamerican.com/article/culture-speeds-up...
[2] https://www.nature.com/scitable/topicpage/evolutionary-adaptation-in-the-human-lineage-12397/ https://www.nature.com/scitable/topicpage/evolutionary-adapt...
> It's an inspiring philosophical concept, but it's like saying 'the world changes with every breath you take'.
It's literally what evolution is. Each generation of organism is different from the next. There isn't some break-point where changes ceased, it's been continuous since the life began, i.e. a continuum.
> They have different attributes for many reasons that have nothing to do with evolution (and are not hereditary). And any real evolutionary changes are so small that they practically don't exist.
The reason is literally evolution. They are different in small (or large) ways, because every generation is different. If they survive and pass part of their genes along to the next generation, their offspring will be different as well.
> It's not conjecture; it's based on evidence: I can't cite the exact science off the top of my head, but humans have been biologically the same for around 200,000 years.
But they haven't been biologically the same. They have changed in each generation of offspring. There wasn't some magic point 200,000 or so years ago when humans stopped evolving. We are still evolving today, every time a new child is born.
I have a feeling you don't actually understand evolution.
we are smarter than humans of 200,000 years ago; symbolic. abstract thinking evolved 50000-60000 years ago (source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048993/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048993/ )