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on humans and nature - the evolution one

besides, how basic is your expectation of the groups understanding of accepted human evolution? would a simple diagram of believed overly hairy ancestors have sufficed or should i have started the thread full blown thesis style? :p really not trying to be a jerk here. i just assumed everyone on the board has had at least some exposure to the hairless ape theory. i started this thread simply to prompt conversation on what on the surface appears to be some oddities with our species. i do not claim to be an expert on any scientific theories. just an idiot who watched a likely unhealthy amount of pbs as a child.

kinch, despite my statements to the contrary this was indeed me being a jerk and i apologize. i shouldn't have said this. it doesn't further the conversation nor is it amusing in anyway. no one said anything to me about this. just after rereading it i don't like how it sounds. my bad man, sorry about being a dick :(.
 
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kinch, despite my statements to the contrary this was indeed me being a jerk and i apologize. i shouldn't have said this. it doesn't further the conversation nor is it amusing in anyway. no one said anything to me about this. just after rereading it i don't like how it sounds. my bad man, sorry about being a dick :(.
No worries at all.

I trust your personal experience as a hairless ape. :wink:
 
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another theory that is likely to get me yelled at (and punched by any woman within swinging distance...). ours also seems to be the only creature in known existence that not only "can" interbreed at the phylum classification level but does so as a function of "normal" reproduction. as far as i can tell men and women are not only NOT the same species, but it seems we don't even belong to the same class on the evolutionary tree. i know this because men, being mammals and as such warm blooded, have the ability to self regulate our body temperature. women on the other hand are not capable of doing so. this is why their feet, butt and hands are ALWAYS cold no matter what the temperature is. based on this i have to assume they are some form of highly evolved cold blooded creature, potentially reptilian... *ponders*

Obviously you're being sarcastic here, but I have to point out that the phylum level of classification puts humans in the same group as fish, our phylum being chordates.
 
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there are two stances on how we as a species came to be. in this thread we assume we evolved from something else into what we are today. please redirect any god talk to the other thread.

basic premise of mine that may or may not be correct. we as a species, when lined up next to every other creature on this planet, flat out do not belong. we are not just unlike everything else on this planet. we are absolutely nothing like anything else on this planet. let me explain...

if you look at a zebra or a dolphin or a house fly. every single species on this planet is perfectly adapted and evolved for its role in its given ecosystem. they all have physical adaptations/evolutionary traits (depending on what term you want to use) that perfectly suit them for the role they play in the food chain.
No species is perfectly adapted to it's environment. They just happen to be the most adapted for their particular niche at this particular time.

we humans seem to have absolutely 0 physical adaptations to any ecosystem found on this planet. we don't have claws of any significant value or mighty fangs. we don't run particularly fast, we can climb... but not in any way resembling positively competitive when compared to what you find elsewhere in nature. worst still, i can't think of a single climate region a human being could be expected to survive in without any form of technology. without access to clothing or fire or any other type of technology, every climate zone on this planet would literally kill us simply from exposure.
We have significant adaptations to survive. We inherited our opposable thumbs from our distant primate ancestors, which allow us to grasp tools and craft things. We have adaptations that allow us to be the premier distance runners on the planet. We evolved an increased childhood over the other apes, allowing more time for development in the critical time when learning occurs best. That increased development allowed our species to conquer fire and create clothes to ward off the cold. The fact that we live in every corner of this world is due to adaptations.

so if you assume we evolved into what we are today from something else and that something else (whatever it was) somehow was more in tune with what we see in nature. why did it evolve into us in the first place? its not like we have any adaptations at all that somehow increase our ability to survive in any eco system found on this planet. in fact, if anything we have devolved from something more capable physically to something less capable. even with the idea that our evolution to "super intelligence" made us lazier and somehow less dependent on physical ability. why would we have devolved so quickly and in such radically silly ways?

further, why did that de-evolution cause pretty much all of mother nature to stop seeing us as prey? its not like we just disappeared while we were devolving from something all hairy and animal-ish then showed back up as fully formed humans as we are today.
This, frankly, is ridiculous. Selection favors those that are most fit, or in your words, more "in tune with ... nature." There is no such thing as devolving. Every change is populations is evolution. If it sticks, then it is a beneficial change in some way.

then there are all these "left over" bits from our pre-evolutionary past. hair and reaction instincts and all these other evolutionary bits. can someone explain arm hair to me? how about the places we have a decent amount of hair? on top of our heads and other... "regions"... sure it helps keep us warm-ish and could be left over bits of fur from our previous state that we just held over. but why aren't we covered in it at birth like everything else on this planet? why does it take months, and in some cases years, to grow something to "protect us" from the elements? why would we not have these things from the get go? you know.... when we are at our absolute weakest?
Vestigial traits are quite common. Our most notorious would be the tail bone. We have them because there has been no selective pressure to get rid of them. A good example would be whales still having pelvic bones, despite not having legs. The bones just float there. In terms of hair, it's certainly a remnant, but it does serve a purpose: it provides warmth, as you said, but there is also probably a sexual selection aspect to hair.

further, we would have had to have had many of our "super intelligence" bits prior to evolving into us today. clothing and fire and hunting and at least limited domestication of animals as well as plant life would have had to have occurred prior to evolving into us today. otherwise... why would we have evolved in the first place?

am i alone in thinking there are serious plot holes in our current theories on human evolution or am i missing something?
Homo sapiens evolved ~100,000 to 200,000 years ago. There is evidence for controlled fire from ~1,000,000 years ago. That would be around the time of Homo erectus. Clothing appears to have arisen ~170,000 years ago when an ice age caused the humans of the time to cover up for warmth. Modern humans didn't brach out with some leaving Africa until around 60,000 years ago. They would not have been dealing with the ice age, so it was most likely a different species using clothes. Hunting has been a constant on this planet since heterotrophs evolved, humans just do it with tools. Domestication does seem to be a purely Homo sapiens thing.
 
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Obviously you're being sarcastic here, but I have to point out that the phylum level of classification puts humans in the same group as fish, our phylum being chordates.

absolutely correct, i was insinuating that men are mammals and women are some form of reptilian species that has yet to be correctly identified and categorized actually :p. please don't tell my gf i said this or she will hit me again :biggrin:

No species is perfectly adapted to it's environment. They just happen to be the most adapted for their particular niche at this particular time.

very true, but our only real (at the time i originally posted that, several have pointed out some reasonably odd and surprisingly effective evolutionary traits we posses since) advantage is intelligence which in and of itself i don't see as an "advantage". for example, having a high iq is nice... but it doesn't actually have any real value in and of itself. for iq to be useful you have to add in knowledge and the opportunity to use that knowledge in a practical way. its like if someone had a supercomputer in their living room. thats an amazing tool in the grand scheme of things. but it has 0 value if you don't know to turn it.

We have significant adaptations to survive. The fact that we live in every corner of this world is due to adaptations.

but is that part really true? sure, we have invented things along the way to dominate the globe. but have we really adapted to any environment on any part of the globe? or have we modified the environment to suit our needs? i don't grow in a "winter coat" to survive ohio winters. i just walk over and turn up the heat. same for the summers. i don't shed for the summer, i turn off the heat and turn on the ac. "i" don't consider that to be a adaptation though. maybe it is...


This, frankly, is ridiculous. Selection favors those that are most fit, or in your words, more "in tune with ... nature." There is no such thing as devolving. Every change is populations is evolution. If it sticks, then it is a beneficial change in some way.

it is ridiculous. i may have misrepresented my meaning there, my apologies if i did. that sentence and really the entire paragraph before it i intended to be seen as being ridiculous because there is no logic to it. including the main point of why under pretty close to any healthy situation in nature humans are really not seen as a food source by any animal. which.... really seems odd because there should have been a time when we were on the menu as it were. at least one would think..?

it provides warmth, as you said, but there is also probably a sexual selection aspect to hair.

outside of sexual selection does it really? how much heat is really retained by arm hair? maybe that explains why women are always cold? all that leg shaving n such :p

Homo sapiens evolved ~100,000 to 200,000 years ago. There is evidence for controlled fire from ~1,000,000 years ago. That would be around the time of Homo erectus. Clothing appears to have arisen ~170,000 years ago when an ice age caused the humans of the time to cover up for warmth. Modern humans didn't brach out with some leaving Africa until around 60,000 years ago. They would not have been dealing with the ice age, so it was most likely a different species using clothes. Hunting has been a constant on this planet since heterotrophs evolved, humans just do it with tools. Domestication does seem to be a purely Homo sapiens thing.

really interesting info. do you happen to have any links on the proof of controlled fire bit? that i was not aware of at all. if thats true it is extremely interesting. 10 years ago or so i heard about a theory that stated cooked meat may promote an increase in intelligence and may have been a factor in the evolution of human intelligence. i don't know if that study ever went anywhere or not. but if there is merit to that thought that would be extremely interesting... i think i will go research that a bit. will reply later :).

remember, i am in no way an expert in this or any other field. i just babble weird shit out loud (far more often than i should) in an attempt to educate myself. mostly because im illiterate. but also because reading is dumb. the book always ruins the movie and the movie is almost always quicker to watch than reading the book. so its really about time management. hell i wouldn't even be here if i thought clarity was working on a script :wink:.
 
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absolutely correct, i was insinuating that men are mammals and women are some form of reptilian species that has yet to be correctly identified and categorized actually :p. please don't tell my gf i said this or she will hit me again :biggrin:
Your funeral 8D



very true, but our only real (at the time i originally posted that, several have pointed out some reasonably odd and surprisingly effective evolutionary traits we posses since) advantage is intelligence which in and of itself i don't see as an "advantage". for example, having a high iq is nice... but it doesn't actually have any real value in and of itself. for iq to be useful you have to add in knowledge and the opportunity to use that knowledge in a practical way. its like if someone had a supercomputer in their living room. thats an amazing tool in the grand scheme of things. but it has 0 value if you don't know to turn it.



but is that part really true? sure, we have invented things along the way to dominate the globe. but have we really adapted to any environment on any part of the globe? or have we modified the environment to suit our needs? i don't grow in a "winter coat" to survive ohio winters. i just walk over and turn up the heat. same for the summers. i don't shed for the summer, i turn off the heat and turn on the ac. "i" don't consider that to be a adaptation though. maybe it is...
I'm combining these parts because I think they come together nicely for what I'm going to type.

When thinking about adaptations, one cannot compare a human to a turtle or a whale. You have to look at our close relatives and our ancestors. We are apes. Our closest relatives are other apes. Going from that base, we can look at what separates use from them. They are well adapted to wooded areas and can climb generally well. But they can't run for shit. Not a single one of them is bipedal. A huge, HUGE adaptation that helped humans become dominant was the evolution of bipedalism and the ability to run. The gluteus maximus on humans is quite large and powerful compared to other apes. Our Achilles tendons are significantly larger as well. Our hips realigned, and our backs became S shaped. Every one of those changes, and many many more, allowed early humans to stand up and run. Running was useful for scavenging, in that one would see birds circling and they'd run there to get the meat before other predators got there; and also useful for running prey to exhaustion. Both of these behaviors are seen in indigenous groups of humans today.

Another adaptation over other apes is our incredibly long development. This would be the main reason for our increased intelligence. A genetic change caused our hominid ancestor to have a longer period of development, which allowed a longer opportunity for learning in the period when learning is most useful. The brain case in our skulls also got larger, increasing the size of our brains and allowing for far more connections. Hair loss seems to tie into this, as it was likely a neoteny that caused the increased development time. A neoteny is when a juvenile form continues to adulthood, like a muduppy. If you look at pictures of many baby apes, they look far more like adult humans that do their adult forms. The theory is that our ancestor went through a neotony, leading to "baby" looking adults, with less hair and more learning. The less hair ended up helping with heat loss. (I just looked this up, because i wasn't sure why it was evolutionarily beneficial)

Going further back, an adaptation over other monkeys gave our ancestor an advantage in looking for food: Color vision. This adaptation came about because of a gene duplication for one color sensing gene that then evolved to sense another color. It is present in our line of primates, but not other lines. This allowed our ancestors to see the bright colors that can mean ripe or dangerous. This gave them the ability to get the best food.




it is ridiculous. i may have misrepresented my meaning there, my apologies if i did. that sentence and really the entire paragraph before it i intended to be seen as being ridiculous because there is no logic to it. including the main point of why under pretty close to any healthy situation in nature humans are really not seen as a food source by any animal. which.... really seems odd because there should have been a time when we were on the menu as it were. at least one would think..?



outside of sexual selection does it really? how much heat is really retained by arm hair? maybe that explains why women are always cold? all that leg shaving n such :p

We have been prey for animals in the past. We just evolved the hands and smarts to create tools, which we used as weapons. The animals then learned to stay away for the most part.

As for the hair, I was pretty much guessing, but now, as I liked above, I've looked it up, and that seems to be a good explanation.



really interesting info. do you happen to have any links on the proof of controlled fire bit? that i was not aware of at all. if thats true it is extremely interesting. 10 years ago or so i heard about a theory that stated cooked meat may promote an increase in intelligence and may have been a factor in the evolution of human intelligence. i don't know if that study ever went anywhere or not. but if there is merit to that thought that would be extremely interesting... i think i will go research that a bit. will reply later :).

remember, i am in no way an expert in this or any other field. i just babble weird [Mark May] out loud (far more often than i should) in an attempt to educate myself. mostly because im illiterate. but also because reading is dumb. the book always ruins the movie and the movie is almost always quicker to watch than reading the book. so its really about time management. hell i wouldn't even be here if i thought clarity was working on a script :wink:.

Controlled fire is still a hotly (haha get it) debated topic among anthropologists. There are claims that evidence shows controlled fire from ~1.6 million years ago. More conservative estimates, relying on habitual use of fire, put the date closer to 300-400,000 years ago. Whatever is actually the correct time, controlled fire was achieved before Homo sapiens evolved. I got that info from here. Coincidentally, that article also discusses cooking leading to increased intelligence. "Longer chronologies for the use of fire include Wrangham’s recent hypothesis that fire was a central evolutionary force toward larger human brains: eating cooked foods made early hominin digestion easier, and the energy formerly spent on digestion was freed up, enabling their energy-expensive brains to grow. Using fire to prepare food made early humans move away from the former feed-as-you-go-and-eat-raw-food strategy and toward the sharing of cooked foods around fires, which became attractive locations for increased social interaction between individuals."

I love talking about this, and anyone interested in it and trying to increase their knowledge of it, it cool by me.
 
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Your funeral 8D
Coincidentally, that article also discusses cooking leading to increased intelligence. "Longer chronologies for the use of fire include Wrangham’s recent hypothesis that fire was a central evolutionary force toward larger human brains: eating cooked foods made early hominin digestion easier, and the energy formerly spent on digestion was freed up, enabling their energy-expensive brains to grow. Using fire to prepare food made early humans move away from the former [Zeke]-as-you-go-and-eat-raw-food strategy and toward the sharing of cooked foods around fires, which became attractive locations for increased social interaction between individuals."

I love talking about this, and anyone interested in it and trying to increase their knowledge of it, it cool by me.

My only comment would be to point out something clarifying but not contradictory to what you wrote: the increased energy from cooked food could not have allowed our brains to grow larger unless they already had the capability to do so but didn't previously have the energy. I only mention this because it is a precarious jump to many who conflate "while alive" evolution to "genetic, as in from birth" evolution. While alive style isn't real, the latter is.
 
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My only comment would be to point out something clarifying but not contradictory to what you wrote: the increased energy from cooked food could not have allowed our brains to grow larger unless they already had the capability to do so but didn't previously have the energy. I only mention this because it is a precarious jump to many who conflate "while alive" evolution to "genetic, as in from birth" evolution. While alive style isn't real, the latter is.
Very true, the genes have to be there to allow the cooked meat to increase brain size.

But, and this is a big but: Regarding the "alive style isn't real", it is. Lamarck wasn't completely wrong. There is an area of research in evolutionary biology called epigenetics, that looks into how factors during an individuals life can effect their offspring. It's really quite interesting, though it's not really anything like what Lamarck postulated.

Here's a journal article about coloration of mice changing due to methylation, which acts to repress gene expression. The researches exposed some of the mice to methyl groups, in the form of folic acid, to darken their coats. They then bred the mice and found that the methyl groups were actually passed on.

Here's
another dealing with humans. This study looked at holocaust survivors for expression of genes dealing with stress. They found, basically, that the survivors were better able to deal with stress than other Jews of the same age that were not in the holocaust. The researches then looked at their children and found that they were actually less able to deal with stress than the general Jewish population.

This is a fairly new field, and new research is being done constantly. It's interesting because Lamarck has been a laughingstock for a century, but it turns out he wasn't completely wrong. Though it's still very safe to laugh, I mean, come on, giraffes necks growing by stretching?! LOL
 
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Very true, the genes have to be there to allow the cooked meat to increase brain size.

But, and this is a big but: Regarding the "alive style isn't real", it is. Lamarck wasn't completely wrong. There is an area of research in evolutionary biology called epigenetics, that looks into how factors during an individuals life can effect their offspring. It's really quite interesting, though it's not really anything like what Lamarck postulated.

Here's a journal article about coloration of mice changing due to methylation, which acts to repress gene expression. The researches exposed some of the mice to methyl groups, in the form of folic acid, to darken their coats. They then bred the mice and found that the methyl groups were actually passed on.

Here's
another dealing with humans. This study looked at holocaust survivors for expression of genes dealing with stress. They found, basically, that the survivors were better able to deal with stress than other Jews of the same age that were not in the holocaust. The researches then looked at their children and found that they were actually less able to deal with stress than the general Jewish population.

This is a fairly new field, and new research is being done constantly. It's interesting because Lamarck has been a laughingstock for a century, but it turns out he wasn't completely wrong. Though it's still very safe to laugh, I mean, come on, giraffes necks growing by stretching?! LOL
That is interesting, but I am very curious as to how this could occur genetically.
 
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I've been lisening to a blog by Malcolm Gladwell called "Revisionist History". I'll leave one episode here for it's social commentary. It can be moved if found to be political for some reason. It's about "tokenism" in society.



 
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That is interesting, but I am very curious as to how this could occur genetically.
It's not actually genetic change. The methylation does not change the genome, but it changes gene expression. The methylation is then replicated when meiosis occurs and that is passed on. Selection can act on the newly expressed trait, but it does not change allele frequency, which is required for evolution to take place. If taken over many generations, the methylation can eventually lead to speciation due to selection indirectly working on other genes and changing allele frequency.
 
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It's not actually genetic change. The methylation does not change the genome, but it changes gene expression. The methylation is then replicated when meiosis occurs and that is passed on. Selection can act on the newly expressed trait, but it does not change allele frequency, which is required for evolution to take place. If taken over many generations, the methylation can eventually lead to speciation due to selection indirectly working on other genes and changing allele frequency.
That is pretty much what I was looking for.
 
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couple of studies i found on a link to cooked food to larger brain/intelligence:

http://www.smithsonianmag.com/science-nature/why-fire-makes-us-human-72989884/?no-ist

http://www.livescience.com/24875-meat-human-brain.html
"The bottom line is, it is certainly possible to survive on an exclusively raw diet in our modern day, but it was most likely impossible to survive on an exclusively raw diet when our species appeared," Herculano-Houzel told LiveScience.

i highlighted this quote specifically only because it validates a part of my original post and that makes me feel slightly smarter :biggrin:. what i take from this is that without a knowledge of fire (ie any form of technology) our species could not survive in the wild. while this doesn't validate my entire argument. im still calling this partially supportive and potentially evidence im not the least intelligent person on the planet. i take the partial wins where i can get em :P
 
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couple of studies i found on a link to cooked food to larger brain/intelligence:

http://www.smithsonianmag.com/science-nature/why-fire-makes-us-human-72989884/?no-ist

http://www.livescience.com/24875-meat-human-brain.html


i highlighted this quote specifically only because it validates a part of my original post and that makes me feel slightly smarter :biggrin:. what i take from this is that without a knowledge of fire (ie any form of technology) our species could not survive in the wild. while this doesn't validate my entire argument. im still calling this partially supportive and potentially evidence im not the least intelligent person on the planet. i take the partial wins where i can get em :P
I have an issue with that quote, and it is likely out of context as I assume the person knows a bit about which they are talking, our species never "appeared." We didn't miraculously suddenly exist. Every step from our ancestors was a baby step, we didn't simply go "now fire!" and boom became a new species.
 
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I have an issue with that quote, and it is likely out of context as I assume the person knows a bit about which they are talking, our species never "appeared." We didn't miraculously suddenly exist. Every step from our ancestors was a baby step, we didn't simply go "now fire!" and boom became a new species.
This is why I love when religious folks, or rather, some religious folks, use the term "missing link." I am the missing link. Every single person is the missing link. It isn't missing, it is gradual. One has to have zero understanding of biology to even ask where the "missing link" is.
 
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