Bogmihia
06-05-2006, 09:32
This was meant to be a reply in the Angry white female thread, but after writing it I discovered the thread is closed. :headbang: I spent to much time writing it for me to simply give up, so I'm starting a new thread just to post my reply (anyway, we were a bit off topic on the original thread). Some of my comments may not fall exactly within this topic, since they were intended as part of a different thread. Ignore them. Feel free to add what you think about the human genetic future.*
I'm of the oppinion that the traits which, because of our technological advancement, are no longer necessary for our survival, will slowly fade away. I'm not advocating eugenics or anything simmilar (I'm short-sighted myself and my heart has a funny shape, so I'd be stupid to do it :p), it's just what I think will happen. I don't even think it's a bad phenomenon. If you don't need it, why keep it? What's your oppinion on this?*
* the bolded paragraphs were added after I decided to start a new thread. You may want to read only them. What's below has less relevance on this thread and may be confusing to somebody who doesn't know what I and my discussion partners were talking about.
A disadvantage will be selected against.
An 'unnecessary' trait might or might not be lost... because it just doesn't contribute.
You're wrong. I'll give one more example and hope you (not necesarily you, it's the plural) understand it. Let's take a trait which was necessary in the past, but is no longer essential now. Keen eye-sight, for example. If you tell me that 50 000 years ago there were as many people in need of glasses as today, I'll call you a liar. So what happened? For a long time, keen eye-sight was an advantage and was selected for in the human population. After the apparition of agriculture, this trait stopped being so important, although it most certainly wasn't a disadvantage. I hope we can all agree so far. What happened later? Every generation, because of random genetic accidents, some of the people with good eye-sight have short-sighted children. If the trait is irrelevant, then those children will have an equal chance to pass their genes to the next generation. Let's call those original surviving short-sighed people "generation 1". What will be the situation in the second generation? On the one hand, we'll have the short-sighted offspring of "generation 1". On the other, the same process that took place one generation before is still active. That is, some people with a good eye-sight will have, because of random genetic accidents, short-sighted children who will not be selected against because of the lack of an environemental pressure (the fact that keen eyesight is no longer important for survival). So the short-sighted population of "generation 2" is composed of the descendents of short-sighted people from "generation 1", plus some who have become shortsighted in that generation. This means that "generation 2" will have more short-sighted people than "generation 1". The same trend will continue in "generation 3", "generation 4" etc, leading to the current situation where a significant proportion of the population is short-sighted.
I can also mention other human traits. What about body strength? It's certainly not a disadvantage to be strong, and yet the modern humans are not as strong as we were in the past. Chimpanzees, for example, are four times stronger than the average male. Strength is obviously a trait which was not selected against, yet it diminished because the positive reinforcement for it dissapeared.
The conclusion is that an unessential trait will be slowly diluted out, because those born by accident without it will not be at an evolutionary disadvantage. We can be sure that every generation, some people carrying that trait will produce offspring who don't have it, those already not having it would also reproduce without any disadvantage, which means that slowly the proportion of people without the trait will decrease. It's really simple.
Our skulls, including jaws and teeth, are shaped to (A) balance and support the size of our brains, and (B) keep us balanced standing upright on our feet, allowing for maximum head movement radius for scanning the environment. And as Dakini (I think) pointed out, our intestines are sized for meat eating.
I wish people who want to make arguments about human biology would learn something about human biology.
Your're making two seriuos mistakes.
1) Of course our skuls are well balanced, but this has nothing to do with the reduction in size of our jaws and teeth, because our skulls were not unbalanced in the first place! Back when our jaws were larger, our skulls were simply positioned differently. The position changed because our jaws diminished, not the other way around. You've got the cause and effect completely mixed up.
2) A carnivor's intestines are three times it's body length (head to anus). A herbivor's intestines are 20 times it's body length. A man's intestines are 8 times the body length. It's pretty obvious they're not designed for meat eating, but for an omnivorous diet.
Gee, I sure wish you'd learn something about human biology. :rolleyes:
So what is the use of the appendix?
Why don't you go back 100 years into the past and ask somebody about the role of our amygdalas?
This is so incorrect, it's actually a little cute. Think about it. You are aware that the general agreement among paleontogists and athropologists is that the earliest human social groups were hunter-gatherer cultures, right? So while the men were hunting, who was doing the gathering? The supermarket deliverymen, while Wilma Flintstone used a mammoth to vacuum the stone hut? No, it was the women and children out gathering plant foods, fish, and small prey. We know this from modern hunter-gatherer cultures, and it is probably the safest bet in history that ancient hunter-gatherers were the same. Meat is hard to get and never guaranteed. Only a few members of the social group will be equipped to go after big game. Plant foods are almost always there, can be gathered by anyone, and are much easier to preserve. But you need more plant food to equal the nutrition of meat, so more hours are spent overall gathering than hunting. Women, therefore, would have spent at least as much, or more, time outdoors as the men.
So, why do women have less hair than men? Have you heard of a thing called hormones? Testoterone causes hair growth and loss in certain patterns. Men have more testoterone than women. Estrogen causes hair growth and loss in different patterns. Women have more estrogen than men. Changes in hormone levels affect body hair patterns in all individuals of both sexes
You really have a problem with the cause and effect thing, don't you? :rolleyes: Of course the male/female differences in pilosity are caused by the hormones. But the different action of our hormones is an effect! The question is what has favored the apparition of these hormonal differences. If you look at chimpanzees, males don't look particualrly more hairy than the females. Something must have triggered the aparition of these hormonal differences between the human males and females. You may give as an explanation the need to dissipate body heat, or whatever you want. But to say the evolutionary cause (and that's what we were talking about) for the increased male pilosity are the male hormones is plain stupid. I'm sorry to say it, but that's the reality. I repeat: the different hormonal patterns observed between men and women have been caused by some environemental factors (the need to cool our brains, if you say so). They are an effect, not a cause.
The word for those people is Inuit. And they don't look like Norwegians, either.
1) I know, I was simply using Dakini's term. If you have a problem, take it with her.
2) I already gave an explanation for that. The Scandinavians also had a positive reinforcement (vitamin D deficiencies) to lose the melanin in their skins. The Inuits :) simply lacked a positive reinforcement to keep it, so the rate of loss was slower.
There are other reasons why you are wrong about the significance of hairlessness. As has been pointed out, it allows for free sweating which is an efficient rapid body cooling system, which was necessary to maintain a healthy temperature in our brains in the hot climate in which we evolved.
Then whay aren't we all bald? :p
I also thought it was cute the way, in an earlier post, you wondered why, if your body generates so much heat, you still feel cold in winter. That's so sweet -- incorrect but sweet -- and irrelevant. The human body has to cool itself rapidly and constantly because the brain is extremely temperature sensitive. It runs at a relatively high heat and, therefore, it cannot stand much increase in the body's internal temperature. That's why, if you get a fever over 105 degrees F, you must be cooled as quickly as possible. Depending on your age and overall condition, staying that hot for as long as 2 - 5 days could cause permanent brain damage.
1) It's not an irrelevant question.
2) Yes, people may even die if they have fever.
P.S. Too many sweets. Watch out for diabetes.
Nope, you're wrong. The genes that control various body functions (such as functions of different skin types) exist and can exist in all human beings. They are either dominant or recessive. But they do not disappear. Human beings to this day contain genes that do not function in our bodies. Such genes are found in some early hominids and other species of animals. They do not function in our bodies now, but there is nothing wrong with them, and there seems to be nothing particular stopping them from becoming functional. Future mutations could easily see these genes reactivating in individuals of our species. Depending on the reproductive choices of generations of human beings, either white skin or dark skin might become more or less rare, but the genes for them likely will not disappear.
It doesn't take all that much energy to maintain DNA.
I've never said the genes would dissappear. What I said was that "the natural tendence would be towards a decrease". And yes, if the environement were to change in the future, the genes and the traits determined by them would become predominant again. However, me and Dakini were discussing what would happen if human science would make the environemental factors influencing skin colour irrelevant. Read the first paragraphs of my post to see what would happen if a trait becomes unnecessary. I'm too lazy to write the same thing twice.
I'm of the oppinion that the traits which, because of our technological advancement, are no longer necessary for our survival, will slowly fade away. I'm not advocating eugenics or anything simmilar (I'm short-sighted myself and my heart has a funny shape, so I'd be stupid to do it :p), it's just what I think will happen. I don't even think it's a bad phenomenon. If you don't need it, why keep it? What's your oppinion on this?*
* the bolded paragraphs were added after I decided to start a new thread. You may want to read only them. What's below has less relevance on this thread and may be confusing to somebody who doesn't know what I and my discussion partners were talking about.
A disadvantage will be selected against.
An 'unnecessary' trait might or might not be lost... because it just doesn't contribute.
You're wrong. I'll give one more example and hope you (not necesarily you, it's the plural) understand it. Let's take a trait which was necessary in the past, but is no longer essential now. Keen eye-sight, for example. If you tell me that 50 000 years ago there were as many people in need of glasses as today, I'll call you a liar. So what happened? For a long time, keen eye-sight was an advantage and was selected for in the human population. After the apparition of agriculture, this trait stopped being so important, although it most certainly wasn't a disadvantage. I hope we can all agree so far. What happened later? Every generation, because of random genetic accidents, some of the people with good eye-sight have short-sighted children. If the trait is irrelevant, then those children will have an equal chance to pass their genes to the next generation. Let's call those original surviving short-sighed people "generation 1". What will be the situation in the second generation? On the one hand, we'll have the short-sighted offspring of "generation 1". On the other, the same process that took place one generation before is still active. That is, some people with a good eye-sight will have, because of random genetic accidents, short-sighted children who will not be selected against because of the lack of an environemental pressure (the fact that keen eyesight is no longer important for survival). So the short-sighted population of "generation 2" is composed of the descendents of short-sighted people from "generation 1", plus some who have become shortsighted in that generation. This means that "generation 2" will have more short-sighted people than "generation 1". The same trend will continue in "generation 3", "generation 4" etc, leading to the current situation where a significant proportion of the population is short-sighted.
I can also mention other human traits. What about body strength? It's certainly not a disadvantage to be strong, and yet the modern humans are not as strong as we were in the past. Chimpanzees, for example, are four times stronger than the average male. Strength is obviously a trait which was not selected against, yet it diminished because the positive reinforcement for it dissapeared.
The conclusion is that an unessential trait will be slowly diluted out, because those born by accident without it will not be at an evolutionary disadvantage. We can be sure that every generation, some people carrying that trait will produce offspring who don't have it, those already not having it would also reproduce without any disadvantage, which means that slowly the proportion of people without the trait will decrease. It's really simple.
Our skulls, including jaws and teeth, are shaped to (A) balance and support the size of our brains, and (B) keep us balanced standing upright on our feet, allowing for maximum head movement radius for scanning the environment. And as Dakini (I think) pointed out, our intestines are sized for meat eating.
I wish people who want to make arguments about human biology would learn something about human biology.
Your're making two seriuos mistakes.
1) Of course our skuls are well balanced, but this has nothing to do with the reduction in size of our jaws and teeth, because our skulls were not unbalanced in the first place! Back when our jaws were larger, our skulls were simply positioned differently. The position changed because our jaws diminished, not the other way around. You've got the cause and effect completely mixed up.
2) A carnivor's intestines are three times it's body length (head to anus). A herbivor's intestines are 20 times it's body length. A man's intestines are 8 times the body length. It's pretty obvious they're not designed for meat eating, but for an omnivorous diet.
Gee, I sure wish you'd learn something about human biology. :rolleyes:
So what is the use of the appendix?
Why don't you go back 100 years into the past and ask somebody about the role of our amygdalas?
This is so incorrect, it's actually a little cute. Think about it. You are aware that the general agreement among paleontogists and athropologists is that the earliest human social groups were hunter-gatherer cultures, right? So while the men were hunting, who was doing the gathering? The supermarket deliverymen, while Wilma Flintstone used a mammoth to vacuum the stone hut? No, it was the women and children out gathering plant foods, fish, and small prey. We know this from modern hunter-gatherer cultures, and it is probably the safest bet in history that ancient hunter-gatherers were the same. Meat is hard to get and never guaranteed. Only a few members of the social group will be equipped to go after big game. Plant foods are almost always there, can be gathered by anyone, and are much easier to preserve. But you need more plant food to equal the nutrition of meat, so more hours are spent overall gathering than hunting. Women, therefore, would have spent at least as much, or more, time outdoors as the men.
So, why do women have less hair than men? Have you heard of a thing called hormones? Testoterone causes hair growth and loss in certain patterns. Men have more testoterone than women. Estrogen causes hair growth and loss in different patterns. Women have more estrogen than men. Changes in hormone levels affect body hair patterns in all individuals of both sexes
You really have a problem with the cause and effect thing, don't you? :rolleyes: Of course the male/female differences in pilosity are caused by the hormones. But the different action of our hormones is an effect! The question is what has favored the apparition of these hormonal differences. If you look at chimpanzees, males don't look particualrly more hairy than the females. Something must have triggered the aparition of these hormonal differences between the human males and females. You may give as an explanation the need to dissipate body heat, or whatever you want. But to say the evolutionary cause (and that's what we were talking about) for the increased male pilosity are the male hormones is plain stupid. I'm sorry to say it, but that's the reality. I repeat: the different hormonal patterns observed between men and women have been caused by some environemental factors (the need to cool our brains, if you say so). They are an effect, not a cause.
The word for those people is Inuit. And they don't look like Norwegians, either.
1) I know, I was simply using Dakini's term. If you have a problem, take it with her.
2) I already gave an explanation for that. The Scandinavians also had a positive reinforcement (vitamin D deficiencies) to lose the melanin in their skins. The Inuits :) simply lacked a positive reinforcement to keep it, so the rate of loss was slower.
There are other reasons why you are wrong about the significance of hairlessness. As has been pointed out, it allows for free sweating which is an efficient rapid body cooling system, which was necessary to maintain a healthy temperature in our brains in the hot climate in which we evolved.
Then whay aren't we all bald? :p
I also thought it was cute the way, in an earlier post, you wondered why, if your body generates so much heat, you still feel cold in winter. That's so sweet -- incorrect but sweet -- and irrelevant. The human body has to cool itself rapidly and constantly because the brain is extremely temperature sensitive. It runs at a relatively high heat and, therefore, it cannot stand much increase in the body's internal temperature. That's why, if you get a fever over 105 degrees F, you must be cooled as quickly as possible. Depending on your age and overall condition, staying that hot for as long as 2 - 5 days could cause permanent brain damage.
1) It's not an irrelevant question.
2) Yes, people may even die if they have fever.
P.S. Too many sweets. Watch out for diabetes.
Nope, you're wrong. The genes that control various body functions (such as functions of different skin types) exist and can exist in all human beings. They are either dominant or recessive. But they do not disappear. Human beings to this day contain genes that do not function in our bodies. Such genes are found in some early hominids and other species of animals. They do not function in our bodies now, but there is nothing wrong with them, and there seems to be nothing particular stopping them from becoming functional. Future mutations could easily see these genes reactivating in individuals of our species. Depending on the reproductive choices of generations of human beings, either white skin or dark skin might become more or less rare, but the genes for them likely will not disappear.
It doesn't take all that much energy to maintain DNA.
I've never said the genes would dissappear. What I said was that "the natural tendence would be towards a decrease". And yes, if the environement were to change in the future, the genes and the traits determined by them would become predominant again. However, me and Dakini were discussing what would happen if human science would make the environemental factors influencing skin colour irrelevant. Read the first paragraphs of my post to see what would happen if a trait becomes unnecessary. I'm too lazy to write the same thing twice.