BumFluff

recently, can't remember what site I read it on, but there was an article concernign some recent findings about the evolution of eyes and some fossils they have discovered.

Bumf said

 

"I doubt that the wearing of clothing would be the only reason why man's ancestors lost their fur. "

 

It is not the only reason. In any evolutionary development like this, we have to look at two sides to the change.

1. What is the adaptive advantage of the change?

2. How does the organism overcome the adaptive disadvantage of the change?

 

For loss of fur, there are two main adaptive advantages often suggested - improved cooling, and improved resistance to parasites. However, that does not answer the question as to why human are the only terrestrial mammal in our size range to go furless. The reason other mammals have not is that they cannot meet point (2) - they cannot overcome the selective disadvantage of going furless. And that disadvantage is, of course, loss of thermal protection, which we get with clothing.

I'd completely agree that clothing did have some sort of effect on ancient man to have lost their fur but I highly doubt it was the precursor to it. Most likely man began losing his fur, began moving northward where it is cooler and clothing use began to increase (or perhaps began spending most of their time in lakes and rivers to cool down?). However I personally believe that overheating of the body due to the change of environment in that area was the major change that lead to it. Actually they could all have occurred simultaneously.

I think the question to ask at this point is 'why were they overheating?'. I'm fairly certain that the climate change wouldn't have been the only reason because, as you said, there are still animals in that area that have fur covering their body even today. Most likely a lifestyle change occurred at the same time. Now what kind of lifestyle change would have to occur to a creature to have such a vast effect, most likely due to the change in climate?

Or perhaps he knows that the best way to true knowledge is to follow the scientific method and demand that assertions be supported.

 

 

If you want a harmless and pleasurable debate, then take it to General Discussion. This is the Biology forum, specifically, the Evolution, Morphology and Exobiology subforum.

Desertification has well been known to be occuring in Africa for some time. News Search for Desertification of Africa and recent evidence, though I can't recall where I read it, supports the theory that ancient man lived on the border between the jungle environment and the desert environment.

Spending time in water does not require hair loss. Seals and otters have the most amazing fur coats. Evolution for an aquatic existence did not lead to them losing hair. Quite the reverse. They evolved fur that traps air - much denser.

 

Human hair loss is much more easily explained. We have had clothing for a long time. Development of clothing permits heat retention without having fur. And by being able to shed clothing, and having no fur, we can hunt with the major advantage over other animals of superior cooling. As I pointed out earlier, this gives hunting stamina that is extraordinarily superior.

I doubt that the wearing of clothing would be the only reason why man's ancestors lost their fur. I believe it has been stated earlier in this thread that the further north you go the more clothing people wear. Heck near the equator the woman and men are almost naked even today. Do you think that a animal covered in fur would even consider wearing some sort of coat? They would easily overheat.

I've seen a film of that - african's hunting a elan I think. However, what struck me was that it was only possible because the humans could carry their water with them. Does this suggest that we started carrying water with us before we lost our hair? Else, surely we'd have suffered from dehydration. Sweating in hot dery places aint a good idea unless water is readily available. This is why I tend towards the AAH prior to us living on the savannah. i.e., we'd already lost our hair.

That's a good point. However regardless if we lost our hair because of AAH or we lost it due to cooling we would still need to carry the water with us or migrate to where the water was. That's why I think that our ancestors were nomadic. They scavenged and hunted for food, storing which they could, until they had to move on when the water sources began to dry up and the desert began to overtake them.

Why would man have lost their hair because they were partly aquatic and what prompted them to become partly aquatic? Why would we have lost that aquatic ability? The only reasons I could think of why man would become partly aquatic is to get food, fishing without rods, or to get away from predators.

why do all apes have to have the same evolutionary history, as in why would they all have to become like people? Do all people have to be exactly alike?

I think it is a mistake to consider some small subgroup of factors and call it a day. In reality, it's all factors aggregated together which led to the differing outputs.

I'm trying to understand what theories could lead to man becoming bipedal and apes not to. Every theory I've read does in no way describe why one group became bipedal and the other didn't. One of the major contributing factors, in my opinion and as stated above, is that desertification at that time attributed to it significantly.

That the groups had slightly different environmental factors acting on their selection.

And that is exactly what I said. But what environmental factors would cause

one group to become bipedal while the other not to?

Don't go jumping off a cliff with a red herring! Leave the red herrings to the creationists. The way you state this implies to me that you are ascribing purpose to evolution. So, back to your original hypothesis:

 

 

 

The final sentence of your hypothesis is pretty much in line with current thinking. Everything leading up to that is not. First and foremost, you are indeed ascribing purpose to evolution. For example, "They needed to walk bipedally back to the safety of the jungle". Evolution does not have a long-term view. It has no purpose. Having a mathematical bent, I think of evolution as being a kind of local optimization function rather than a global optimization function.

 

The knuckle walking ape and the bipedal human differ in skeletal structure, musculature, nervous systems, respiratory systems, etc. Bits and pieces of every part of our body had to change. This many changes is not the work of one mutation. Our ancestors did not switch from knuckle walking to bipedalism in one fell swoop. The changes piled on top of each other, eventually leading to full upright bipedalism. The ability to carry weapons and lug food around is an advanced skill. Something else drove the changes that lead up to these abilities. That something else conferred an immediate, local optimizer kind of advantage -- like the ability to see lions off in the distance instead of seeing the lions right before they attack.

You seem to be saying that bipedalism grew of chance. No I don't believe evolution has an all out purpose. Evolution doesn't work to achieve an ultimate goal. It works as with little evolutionary steps through sexual, natural or ecological selection. Bipedalism took a long time to occur, it didn't occur overnight. You misunderstand what I'm saying. What I am saying is that, because of the environmental impact, our ancestors needed to adapt to their surroundings which would eventually lead to bipedalism. Desertification of Africa didn't occur overnight. There wasn't some great God in the sky that said "Let it be!". It took a long long time and humans were adapting to this over a long period of time. The local optimization functions are the reason, in the theory I posted, why one group remained apes and the other group evolved into humans.

I've been reading theory after theory of why bipedalism occurred in humans but I have not read anything stating why one group of ancestor evolved one way while the other evolved the other way. What do you propose is the 'correct' theory of why this occurred?

In saying we are not descended from apes (or monkeys), you are in a way making things worse. We are descended from apes (and monkeys). Just not today's apes (or monkeys).

 

Most creationists are Caucasians from the United States. Turn the question around on them: "I would guess that your are an American of European ancestry. If you're descended from Europeans, why are there still Europeans today?" Then say how this shows the question to be a lie, a misrepresentation of the theory of evolution. Then you can go on with "every non-emotional argument against evolution is a misrepresentation of evolution, and an intentional misrepresentation at that."

I don't know why we continue to argue about this. I have stated that comparing mans ancestors of yesteryear, after the separation of man and apes, are in no means comparable to the apes of today. They went through different evolutionary trends. Which is pretty factual if we in fact did come from one common ancestor, as I believe. Stating that there is no way that ancient man would want to carry food to their place of residence because the apes of today don't is like saying all our mammalian ancestors must have run and jumped off cliffs to their deaths because lemurs do it today.

I've also explained why this separation took place in my opinion. Because of their different areas of habitation.

To Bumfluff

 

I am going to be nit picky here. Humans are descended from apes. In fact, we are still apes. We belong to the Great Ape group of primates. The only thing is that we are not descended from modern apes.

 

Re clothing. I agree with you that clothes were worn a hell of a long time ago. I think that simple clothing was invented way back when our ancestors were hairy apes. It was only after this invention that our ancestors could access the advantages of hairlessness without the disadvantage of dying of hypothermia. Once clothing was worn during the cold hours of the day, and shed for hunting, the evolution of hairlessness would have been rapid.

 

What was the earliest clothing like? Lots of artists draw pre humans wearing animal skins. I doubt it. Untanned skins go rotten really fast. And tanning is not easy. It can be done with tree bark, but that leaves a lump of leather like a sheet of plywood. Not well suited to clothing.

 

I think it is more likely that the first clothing was a variation on woven plant fibre. If you weave a mat of that type, and interlock animal hairs or bird feathers into that mat, you will end up with a type of blanket that will keep you warm very well. Sleeping under that mat during the cold hours would add to warmth. Wrapping it around you would keep you warm later.

 

Making actual clothing (as opposed to a simple blanket) would be more difficult, but pre-human intelligence was probably up to the development.

I completely agree that pre-human intelligence was, most likely, perfectly capable of making clothing. What do you think is more likely though: Prehistoric man began wearing clothing because they were cold and wanted to stay warm or prehistoric man began wearing clothing as a means of showing their rank in society much as Darwin's savages did.

Do you think that clothing came before or after man became bipedal? And where does bipedalism fit into the evolution from ancestor to man?

That silly monkey objection keeps coming up. It is a non sequitur, and I gave one way to beat it show it for the silly argument that it is. That the same people continue to raise the same objection over and over even after having been told that the objection is invalid means they are not doing so out of ignorance. They are lying. This is OK because lying in the defense of ones religion apparently is not a sin.

 

We both know that we are descended from Australopithecus and that Australopithecus was an ape, so why join them in the lie and say we aren't descended from apes?

I think it comes from me surfing so many forums and arguing again and again why there are still monkeys around today. It's just one of my pet peeves that has grown stronger and stronger with each argument I have with someone stating the contrary. However what I was trying to get at with my original argument of "we are not apes" was that we are not directly linked to modern apes. They are not in the same line of lineage as us and they went through different evolutionary trends than modern man did. Arguing that modern apes do not carry food in their hands today is in no way proof that ancient man, after being separated from prehistoric ape, did not carry food in their hands as a means of storage.

My argument is that ancient man separated from apes because apes lived in an area that didn't go through desertification at that time while ancient man did, then forcing them to forage and scavenge for food which then forced them to become bipedal. something prehistoric apes didn't have to do.

SkepticLance never said that we are in his post.

 

We are descended from apes. Just as the dire wolf is an extinct species of canids, Australopithecus is an extinct species of hominids, aka great apes. As Australopithecus is one of our direct ancestors and Australopithecus was an ape, we are descended from apes. Furthermore, not only are we descended from apes, we are apes.

 

Some object to saying that we are descended from apes on religious grounds. These religious objections have made some who do ascribe to evolution reject the claim that we are descended from apes. These non-religious objections are based on invalid of the claim by those who believe in creationism. One such objection with saying that we are descended from apes implies we are no longer apes. We are apes. End of story.

 

Another objection is that saying that we are descended from apes implies we are descended from the apes extant today. This is the stupid "if humans are descended from monkeys, why do monkeys still exist" non sequitur. The only way to answer this question is "it is said most Americans are descended from Europeans, so why do Europeans still exist?"

 

These objections yield to the creationists. Take the high ground: Not only are we descended from apes, we remain apes to this day.

I am aware that he didn't say in his posts directly that we are descended from apes however it was what was implied than as is what you are implying now. I am not religious. I am aware that man and apes are of the same family. However continuing to say that 'man descended from apes' drives the theists to continue to ask the argument later in your post. I think it better to state 'Man and apes are descendants of the same ancestor' than say 'man descended from apes' because as long as we continue with this statement the longer the ignorance of the statement will continue to effect those that are unknowledgable on the subject and they will continue to ask, out of ignorance, 'If we are descended from monkeys why are there still monkeys?'

I enjoy reading astronomy magazine and a few others. Basically if I see a science magazine at the store I'll usually get it regardless of what it's called. One website that I have not seen mentioned here yet is physorg.com Much the same as sciencedaily but with several different stories and different takes on those stories.

To Bumfluff

 

A couple of points.

 

First : Apes do not carry food in their hands. They carry it in their stomachs. Our early ancestors would have done likewise. However, carrying tools or weapons is a good reason for upright stance.

 

Second ; Relating to hairlessness. Your theory is not new. Loss of hair as a cooling mechanism has been proposed many times. In fact, one of the few special physical attributes humans have is extreme stamina - if you are young, male, and physically fit - and at least some in each tribe fit that description. This permits a special kind of hunting. To chase a gazelle or similar prey animal until it keels over from exhaustion. This is still done by some African tribes. One reason humans can do this is due to lack of hair and a cooling system that is far superior to most terrestrial mammals.

 

The problem with that theory is that it does not deal with the downside. That is : if you lack hair, how do you deal with the very cold conditions that crop up from time to time - usually early morning - and happen even on the equator. It is my belief that no other terrestrial mammal in our size range has lost hair because they cannot cope with this problem. Humans and pre-humans, however, had simple technology. The use of fire or clothing would permit humans to stay warm when it got cold, and thus lose hair, giving the benefit of better cooling for hunting. No other animal has technology and can do that.

We are not descended from apes. We descended from the same ancestor as apes have. (Which I am sure you are aware of since I have been reading this forum for quite some time now.) If the food sources were beginning to dry up due to desertification and less vegetation you don't think that early man, with his superior knowledge, would have stored some away to eat later much as mammals of lesser intelligence are doing even today?

I'm aware the hairlessness part isn't knew. I actually have been reading many websites on this topic and the hairless loss due to cooling is the most accepted throughout.

Another belief I have is that ancient man began wearing clothes, not because he wanted warmth, but because it was more of a status symbol. When traveling in packs one of the members of that pack would be the leader and they would be wearing the clothing or markings to signify as such. Eventually, as it began getting colder, man began wearing more clothing to keep warm. Archeological discoveries dealing with clothing turned up first I believe at most 10,000 years ago. (As I believe has been stated earlier in this thread or in another dealing with much the same thing.) However I do believe that man has been wearing clothing for quite a lot longer than that.

I actually made a post on anopther site the other day dealing with this exact thing. I actually might have got the original idea from this website. Here it is:

"I've recently been thinking about this a lot recently and have come up with a likely scenario that lead towards the separation from man and apes.

Recent geological evidence has shown that millions of years ago Africa began turning from a lush jungle area to a desert climate through desertification and that areas between different jungle environments were separated by vast stretches of savanna. It is my belief (Although I'm fairly certain this has been proposed before) that our ancient mammalian ancestors lived on the borders of these jungle/savanna wildernesses. To forage and hunt for food they needed to travel outside of the safety of the jungle, both armed with weapons such as sticks or clubs and in packs, to gather what they needed. Having a weapon in one hand and a pile of food in the other didn't really allow for movement on all fours. They needed to walk bipedally back to the safety of the jungle. Eventually their bipedalism grew enabling them to carry more food as well as enabling them to protect themselves better. With bipedalism becoming more common it allowed our ancestors to free up their hands which would then provide them the means of more tool use, better tools and subsequently bigger brains.

The question of how we lost our body hair is one that I agree with the experts on. We lost it because with the more active lifestyle of foraging and hunting for food on the savanna caused our ancestors to overheat. When our bodies adapted to this more active lifestyle it resulted in the loss of hair as means of cooling. Why do some animals still grow hair in that part of the world you ask? My answer is that the animals that do grow hair use it as a means of protection from the Sun. The animals that live in that part of the world are built for short bursts of speed in order to catch their prey (Or if they are herbivores they spend most of their time merely standing around eating plants). They wouldn't overheat they way our ancestors, who weren't built for running long distances on the savanna, did because they don't have to work as hard to travel such vast distances.

The loss of body hair would lead then directly into the darkening of the flesh that formerly laid underneath the hair due to the protection of radiation from the Sun. It is a commonly held belief that the whitening of the skin for certain races occurred because of the amount of UV radiation from the sun at more northern climates. My belief is that while this is only partly true it is nowhere near the whole story. If it was merely due to UV radiation from the sun then chances are that the northern population would still be dark skinned because there would be no reason at all why the skin would become lighter. Dark skin is a better protection for radiation from the sun. Proof is in the fact that the darker skinned you are the less of a chance you have of getting cancer due to the Suns radiation and in effect less of a chance in the radiation from the Sun causing genetic alterations.

On the other hand it is a well known fact that our bodies metabolize vitamin D through certain types of radiation they take in from the Sun. Dark skinned people in northern climates have a greater chance of having vitamin D deficiency because of the less direct sunlight than in equatorial climates. This is the reason why milk and other products are often fortified with vitamin D. It is my belief that human flesh began whitening because protection from the Suns radiation was not needed in more northerly climates as well as the amount of Vitamin D lighter skin could take in."

I'm wondering if anyone sees any flaws in this argument?

I'm not debating that Pluto might be too small to be considered an actual planet, what makes it stupid to demote Pluto is the fact that every astronomy book ever written calls Pluto the ninth planet, not to mention the fact that everyone has heard of Pluto, whereas Ceres and Eris are virtually unknown to most people. Besides, Pluto has a moon, and a very thin atmosphere (at least I think it does). The point is that Pluto has always been known as the ninth planet, and I think it should still be, if for no other reason than to keep all of the books accurate.

Ceres was once known as a planet before they discovered that there was an asteroid belt. If we go by what you say Pluto should actually be the tenth planet and whatever planet this thread mentions should be the twelfth planet. Or maybe the thirteenth or fourteenth.

How did they figure that out? It's rather interesting

http://www.sciencedaily.com/releases/2008/05/080529141404.htm

I don't think when people say "information canot be destroyed" they were talking about information written on a piece of paper or something you thought about yesterday. I think what they are talking about is on the quantum level is it not?

Regardless... everyone has a different belief in what ghosts are or what makes a ghost. One possibility I posted on another forum is perhaps all matter in a specific spot reacts to energy around it. If there is enough energy (I'm talking about the electric currents inside your brain when you think) that energy will flow and be stored in that particular form of matter. At specific times that information is played back from that particular piece of matter.

Another thought I had about a year ago is this. I pictures time like a ribbon that was folded over and over ontop of itself. Every once in awhile along that ribbon it's depth lessons so much that another part of the ribbon seeps through and the matter within that ribbon of time momentarily shows itself to that ribbon whos depth lessened.

Anyways I'm probably making very little sense to everyone and after reading my post I'm making very little sense to myself so I think I'll just stop here for now.

I found this section of your blurb eye opening:

given the lattice of shroendingers cat

I was looking for information regarding this subject after reading this post and came across this http://map.gsfc.nasa.gov/universe/uni_matter.html which states that baryonic matter is very different than dark matter as dark matter is also known as non-baryonic matter.

I've read that the water the was formerly on Mars had too much salinity to create life. Giving the amount of Salt in the water how low would the temperature have to fall in order for it to freeze? I know that salty water on Earth needs to fall far below the temperature of what normal unsalinated water would freeze at.

Even if we find life (or evidence of life) on other solar system planets it is not evidence that life has formed more than once, as there's quite alot of evidence about single cell life forms surviving in space and feasibly travelling planet -> planet....

Chances are if we find life in other Solar Systems those lives would have evolved independantly. The possibility that a living organism being transported from one planet in one solar system to another planet in another solarsytem is so remote I don't even have the words to describe how remote the chances are. It has absolutely nothing to do with how often a living microbe is transported via asteroid from a planet, it has more to do with the distance between the planets and how unlikely it is that an asteroid would travel millions of miles across space only to crash into another planet orbiting some distant star and have that still living organism begin to adapt and breed in it's new surroundings.

The possibilities of life originating within our solar system and being spread out, still within oru solar system is more likely but it is still a long shot.

If clues of the existence of life on the bodies within our solar system that may be able to support it besides Earth, namely under the surface of Mars and under the ice sheets of Europa, are found to support or to once have supported life I'm fairly certain that there are quite a lot more possibilities of intelligent life elsewhere in the universe. Until we discover what exactly makes a lifeform and under what specific conditions a lifeform can exist I think that anyone saying one way or the other is merely a guess. If life can form 4.5 billion years ago on Earth under those harsh conditions and if life can live near the heat ducts of the ocean it can survive almost anywhere. Living microbes have also been tested and have been found to be able to survive in the extreme cold of space.

All animals need is some type of little shove to get going and they can easily adapt to their surroundings. To think that life couldn't evolve aside from how it evolved on Earth is just ludicrous. I'm actually reading a book right now that deals with exactly this sort of thing. It states that non-Earth like life is probably very abundant in the universe. When people speak about how there is probably very few worlds with life on it they probably mean Earth-like life.

The cyclic universe theory (big crunch) has continued to be updated as new discoveries are being made. Dark energy is thought by those that support this theory to be a type of energy that will eventually diminish and gravity will take over beginning the big crunch.

Another theory, spelt something like ekpyrote, theorizes that two branes (part of string or M-theory) will eventually coalesce and the cyclic universe will begin over again.

I believe that the universe is 4D. For instance if you could bring a 2D person to Earth their 2D brains would not understand the concept of 3D objects and would not see the 3D universe in the first place. This is like us 3D humans, we are unable to understand the concept that the universe has a 'Fourth' dimension. dark matter could also be 4D as it cannot be see or detected by anything 3D but we know that it has a fundamental part in the creation of the universe

If the universe were 4d we could still see the 3d shape of the 4d object. Taking your example a 2d person would be able to see a 3d object along the plane on whnich it exists. As that 3d object moves through the plane the 2d vision of the object would change for the viewer until it completely evaporated. The evaporation for the 2d viewer would take place when the 3d object passes completely through the 2d plane.