Human evolution from a scientific stantpoint - Scientific debate, not a religious one

Well nosoul closed the religion topic, but not before blanka was able to make a post concerning the topic of human evolution that I brought up. Thus, I'd like to talk a little more on the topic of human evolution.

This topic is from a SCIENTIFIC standpoint, not a religious one. So if anyone posts here saying something like "ur wrong tho cuz evolutin doesnt exist god made man," then that's gonna be considered spam. I've been in search of a clean, straightforward debate for quite some time now. My debates on BG have more or less run their course, so I figured I'd return to my roots here on this forum. Now, let the human evolution debate begin!

blanka09 said...

Ok.. Let me put it this way.. Humans didn't evolve from chimpazees.. cause if they did.. Why didn't the other chimpazees involve??

There was a special on the discovery channel a year or so ago that I really wished I had recorded. You might be able to find an article about the program on the Discovery Channel website, or possibly backorder a copy of the program.

Either way, that's a good question. If humans evolved from chimpanzees, then why didn't ALL chimpanzees evolve? First, you'd have to take a look at evolution at large.

What causes evolution? The biological definition of "evolution" is the "change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species." (source: http://dictionary.reference.com)

The result of natural selection. Look at wild animals, or more specifically, animals that hunt and live in packs or herds. More specifically, look at creatures such as the wolf, lion and monkey. All three of these creatures are family-type animals. The females protect the children, and the males protect both the females and the children. Now, the males in the pack do not always get along. When this happens, one or more males will challenge the leader of the pack. The loser is exiled from the social group. Sometimes, the loser will be followed by a share of females and children, and strike out on their own. Scientists believe that this is the spark that lit the fuse of the stick of dynamite called "human evolution."

Take a look at a human and a chimpanzee. If you look at a strand of chimpanzee DNA, you will find that it matches a strand of human DNA almost completely, making a match at 99.4% indenticality. Now take a look at the physical aspects. Both human and chimpanzee have two arms, two legs and a head. The head contains two eyes, two ears, a nose and a mouth, in almost exactly the same facial positions. Chimpanzees have tails, while humans do not. HOWEVER, we do have a tailbone, which provides evidence that human beings, lower on the evolutionary ladder, once had tails. But for some reason, we no longer needed them, and eventually evolved to the point where tails were no longer part of our anatomy. Humans and chimpanzees share the exact same internal organs and various systems--nervous, reproductive, digestive. All organs are located in the exact same areas of the body as in humans. Finally, take a look at their brains. Similar brain size and shape (proportionally). They have the ability to think...they can plan, they can solve puzzles, and they have the ability to use simple tools. Socially, they contain the same basic primal social, family and hierarchial traits as basic humans. Both are also very territorial, and will protect their territories and families with fierce savagery.

How can two creatures be so similar, both anatomically and mentally, and yet not be related? Now, for the theory of the human evolution.

Remember what I said above about natural selection? About how one group of creatures from a larger social family will be outcast? Well scientists have conjured up the following theory:

Around five million years ago, there was a schizm in the social structure of a large group of mammals....either a relative of the modern-day chimpanzee or ape or whatever. A large portion of this social structure was outcast, being cast out of the jungles and forests and into the grasslands and plains of africa (where most scientists believe human evolution first began). Over time, these monkeys became bipedal. They learned to balance, stand and walk on their hind legs. The reason for this was so they could peer over the tall grass in order to spot predators. Therefore, the first step of human evolution. Over the next 4.8 million years or so, this large group of human-like mammals continued to evolve, until finally forming homo sapiens around 200 thousand years ago. To be honest, I'm not too sure about the details surrounding the period of time after the outcasts were sent into the grasslands, which is why I didn't specify on anything. Once I find the program or article from the Discovery Channel, I'll elaborate a bit more. But that's what scientists believe. Human beings evolved from an outcast group of chimp-like mammals.

Now, why didn't the rest of the chimpanzees evolve into humans, you ask? Simple....they had already adapted to their jungle- and forest-type of environments. Therefore, no evolution was necessary. The outcast group, however, was suddenly thrust into an alien environment. They had no instincts of how to survive in such an environment, and therefore were forced to adapt and evolve. No evolution was necessary for the jungle chimps because they had already adapted to their environment.

Now an earlier species known as the Australopethicus Africanus or in the early man is where we evolved from. From that to the homo habilis (cause they could handle stuff).. to the homo erectus (cause they could walk straight) and to the present homo sapiens.. (cause they think.. which isn't sometimes good for them.) Now do I believe in what I've just wrote.. maybe.. maybe not. But that's just the origin of the present human beings according to science.

Actually, the origin of present-day humans goes back a little farther than the africanus, and you also skipped a few key stages in human evolution. The origin of present-day humans actually looks something like this:

(source: http://www.onelife.com/evolve/manev.html)


[quote]If infact the science was true and correct and accurate all along, then why haven't the homo sapiens evolved.. after living for such a long time?? These are just some of the questions.. that how should I say.. distorts my belief in science and evolution as the origin of man.

Take a look at the chart displaying the origins of human evolution. The first stage of human evolution lasted 1 million years. The second lasted 300 thousand. The third lasted 1.3 million. The fourth lasted 1 million. The fifth and sixth, which coexisted at the same time, lasted 800 thousand. The seventh lasted 1.6 million. The eighth lasted 200 thousand before we split off into neanderthals and humans, and the neanderthals died off after 170 thousand years. Now I know that adds up to more than 5 million years, but there was some overlapping of species here and there (anamensis to afarensis, afarensis to africanus, and homo erectus briefly overlapped with the existence of both Australopithecus robustus and Homo habilis, which coexisted with each other.

So in the past 5 million years, there have been 10 different species of human in the evolutionary ladder, including present-day humans. Now you say "why havn't homo sapiens evolved?" Well there are a number of answers to that question...

1. We have indeed stopped evolving, due to the fact that we no longer have to adapt to our environment. Due to our technology, we are no longer forced to adapt to our environment, because we now have the ability to make our environment change in order to accustom our needs and comforts. Therefore, evolution is not forced upon us.

2. Evolution is still occuring, but has slowed down (due to the same reason stated above). We no longer have the need to physically evolve, so our brains and mental capabilities will continue to evolve over the millenia. At this moment in time, we are only able to consciously access 10% of our brain. Over time, maybe we will evolve the ability to access even more.

3. Evolution is still continuing, but we just havn't seen any sudden changes yet. Remember, homo sapiens are still young. We have only been around for 200 thousand years. If you do the math, the average amount of time it takes for one specie in that chart to evolve to the next is an AVERAGE of 500 thousand years. We aren't even halfway through that. Therefore, we havn't seen as much change becuase we havn't been around long enough to require change, which gives rise to the BELIEF that we have stopped evolving, which is highly unlikely.



Okay, like I said above, I want a SCIENTIFIC, FACT-BASED discussion here. This topic is NOT about the existence of god, heaven & hell, the bible, the torah, the teachings of Siddharta Guatama, etc. This debate is about the idea of human evolution. If you can't provide facts and evidence to support your case, then don't post.

I'm *HOPING* for an actual debate here. Let's see if anyone can give that to me. I mean, if Hibiki could make a successful topic last year about the theory of relativity, I HOPE i can create a successful topic about human evolution.



Edited By Shauku on Mar. 22 2004 at 18:17

[Angel-Eyes]

dont worry youll get a debate............just let me get my sources and ill be back

[TarkanX]

2. Evolution is still occuring, but has slowed down (due to the same reason stated above). We no longer have the need to physically evolve, so our brains and mental capabilities will continue to evolve over the millenia. At this moment in time, we are only able to consciously access 10% of our brain. Over time, maybe we will evolve the ability to access even more.

We don't use 10% of our brain, any neurologist with a Ph. D. will tell you that. We use all of the parts of our brain, just not at the same time, since firing all neurological impulses at once can cause brain damage or even a stroke.

If we did use 10% of our brain, we would be incapable of doing anything, we wouldn't be able to speak, listen, think or remember.

[Evil-Blanka]

[quoteost_uid0="kester-"]dont worry youll get a debate............just let me get my sources and ill be back[/quote]
yo it is human evolution cuz through years your bodey go through changes like your feet grow or somthing like that take pokemon for exsample when slowbro evolves it gets older and evolves in to sloking he can walk he is taller

[MasterX05]

Tarken is dead right only at certain times u would use a part of your brain. When you are driving you are concentrating on the road and others cars. When you are running u are using diffrent part of the brain or like when you are in a ocnverstaion, or taking a test. It is impossible to use ur brain at 100%. So unless u are doing 50 things at once I doubt that it would rise any higher.

[m0u5y]

how can we evolve when the technology and medical discoveries we have come up with are hindering it. if you think about it, since we can cure so many desieses then the whole survival of the fittest cant work. if the "good" genes cannot be passed down and the "bad" ones are kept in the genetic pool then we can NEVER evolve, at least phisically. Now, mentally, that's another matter. we have been gaining knowledge, and for one you can say that our ways of life and the ways we apply the knowledge are evolving. we might be getting smarter and maybe that is the fated way humans have to go toward (even though ive noticed that kids now a days are getting dumber.) if we are evolving, we are doing so by losing teeth generation after generation, having genetic conflicts when interbreeding with people from different countries (as for example, im half italian and half american and my teeth dont fit in my jaw lol) getting weaker because our bodies are use to medicine working for them instead of their own immune system... no we didnt evolve from chimps, chimps and humans evolved from a common ansestor accorting to scientific findings. i mean hello, we have a common ansestor with bugs! people get confused because humans and chimps have a great deal of genetic info in common. the defenition of evolution is A gradual process in which something changes into a different and usually more complex or better form. it says better not worse. another factor involved is that humans will change the enviornment to suit their needs. if evolution occurs to adapt to the enviornment how can it happen when the enviornment is manipulated by humans?

TarkanX said...

We don't use 10% of our brain, any neurologist with a Ph. D. will tell you that. We use all of the parts of our brain, just not at the same time, since firing all neurological impulses at once can cause brain damage or even a stroke.
If we did use 10% of our brain, we would be incapable of doing anything, we wouldn't be able to speak, listen, think or remember.

Forgive me for not clarifying. Yes, we use all the different parts of our brain, all the different sections and lobes. What I meant was that we cannot FULLY access the potential capabilities of all the different parts and functions of the brain. What I meant was that if you take all of the brain functions we can access, both subconsciously and consciously, and put them together, it'd only still be about 10% of the entire brain.

Of course, I know that you cannot access the whole of the brain simultaneously, for the exact reasons you stated above. What I meant was that as a whole, human beings are only capable of accessing 10% of the brain's POTENTIAL ability. As a whole.

m0u5y said...

how can we evolve when the technology and medical discoveries we have come up with are hindering it. if you think about it, since we can cure so many desieses then the whole survival of the fittest cant work. if the "good" genes cannot be passed down and the "bad" ones are kept in the genetic pool then we can NEVER evolve, at least phisically. Now, mentally, that's another matter. we have been gaining knowledge, and for one you can say that our ways of life and the ways we apply the knowledge are evolving. we might be getting smarter and maybe that is the fated way humans have to go toward

[color=green]I covered that in my second possible answer to the question "why aren't we evolving anymore."[/quote]

if we are evolving, we are doing so by losing teeth generation after generation, having genetic conflicts when interbreeding with people from different countries (as for example, im half italian and half american and my teeth dont fit in my jaw lol)

That's not an example of evolution, no. There are no genetic conflicts between people of various races and "interbreeding." You being half italian and half american (i suppose you mean american indian?) is NOT the reason for your dental problems. I am half italian, the other half comprised of scottish, english, polish and native american descent, and I have no strange physiological problems, so the idea of "genetic conflicts when interbreeding" goes right out the window.

The genetic difference between people of various nationalities is very minor, when considered against the whole of the race. Things like skin color, hair color, hair texture, etc, are all determined by a minor one or two genes in the body that can be evolved rather rapidly. The possibility of having a genetic "conflict" is slim to none.

no we didnt evolve from chimps, chimps and humans evolved from a common ansestor accorting to scientific findings. i mean hello, we have a common ansestor with bugs! people get confused because humans and chimps have a great deal of genetic info in common.

That's more or less what I said in my post....that we evolved from, and I quote, "a relative of the modern-day chimpanzee." I simply said "chimpanzee" during most of my post because I figured it would be easier than saying "a primitive version of the Pongidae pan troglodytes."

But yes, you're correct. The modern-day chimp and the modern-day human both evolved from a common ancestor. The only difference is that the modern-day chimp underwent very little evolutionary activity in the past 5 million years, whereas us humans underwent a substantial amount of evolutionary activity.

We don't have a common ancestor with bugs, but we do have common ancestors with organisms similar to the amoebas that you could scrape off the inside of your cheek.

the defenition of evolution is A gradual process in which something changes into a different and usually more complex or better form. it says better not worse.

That's the generic, basic definition of evolution. In this instance, evolutionary biology, the definition of evolution would be "change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species." By common sense you would figure it would be a better version of the specie. But we are not evolving into a "worse" version of homo sapiens sapiens. We're just evolving into a "different" version. We both share common grounds in the fact that you and I both believe that human beings have stopped or considerably slowed down human evolution on the physical level. I nowbelieve that we are beginning to evolve on the mental level.

An extraordinary example of this, though fictionary, would bein the movie "The Time Machine," based on the novel by Jules Verne. Human beings forced themselves to breed into select castes focusing on different traits. One caste focused on evolving their physical abilities, another their mental abilities. I believe human beings are going to start evolving towards the latter....our brainpower will continue to evolve while our bodies physiclaly do not.

another factor involved is that humans will change the enviornment to suit their needs. if evolution occurs to adapt to the enviornment how can it happen when the enviornment is manipulated by humans?

I already addressed that point in the very first possible answer to the question of "why have humans stopped evolving?" Humans are capable of manipulating our environment to suit our bodies, and therefore evolution has been halted or slowed, for the time being.

[VampireNinja]

Here we go again.... :biggrin:

[m0u5y]

hahah! ok well, see on my father's side there the trait of small mouths is common, on my mother's side its the opposite. oh and im half american... when you say american you really dont know what the heck that is, i know a little irish and some other mess is in there but that's about it. how about the fact that genetic traits for a specific region can be useless or hindering when a person lives in a different one. to tell ya the truth, too much green reading lol... i kinda skimmed through it, good exercise for my biology thesis. :alien: well at least i know im not alone with my weirdo ideas lol. the thing is, humans travel all over the planet, unlike other species who evolved because somehow the were seperated and werent able to re-meet. another problem, now how are you going to deal with genetic engeneering? humans are a nuisance, look at what we're doing? we're goin over nature's head and breaking the laws of evolution lol.

[viper2040]

whoever made that arguement that all chimps would have evolved is a moron who dont know how evolution works.

Heres a quick summary:
One chimp has an abnormal, higher functioning brain, and he happens to be more successful at surviving than other chimps. He sucessfully mates, and the next generation retains the "abnormal" genes. Over time, a distinct species forms. Sometimes, the old species dissappears, but not always.

This is a VERY simplified, not 100% accurate summary. But the key point is that its NOT some "force" that causes the entire species to change at once--its "mutations" that occur within perhaps a single individual in each generation, and slowly successful traits become dominant.

Not that I know whether its chimps we supposedly evolved from....



as for the religious part, whos to say our "creation" by God was not actually an evolution process--a "day" for him is who knows how long. (I dare you--call this spam :biggrin: )