Primitive snakes

[JimmyDavid]

Primitive is relative to ancient.
I guess everybody agrees that evolution takes a lot of time. Therefore, an ancient species has had more oportunity to perform changes than a modern species.
I don't understand why scientists say that Boas & Pythons are the most primitives snakes because (get this).....they still show remains of lizard bones from where they evolved!!!!!!!?????

That's exactly PAINT-FRESH evolution, it proves that they haven't been around long enough to get rid of those traces.

Anyone else starting to see it my way?

[Katt]

Boids are more primitive than colubrids, relatively speaking b/c colubrids have evolved enough to lose these bone remnants.

[CamHanna]

an ancient species has had more oportunity to perform changes than a modern species.
When an ancient species performs these changes does it not become a modern species?

I don't understand why scientists say that Boas & Pythons are the most primitives snakes because (get this).....they still show remains of lizard bones from where they evolved

That's exactly PAINT-FRESH evolution, it proves that they haven't been around long enough to get rid of those traces.
Boids also lack the venoms of advanced snakes (vipers, colubrids, elapids).

It takes a lot of time and the proper circumstances to become a snake. The current theory is that when varanid-like-lizards became more fossorial they lost a lung, their eyelids and their eyes. The eyes reformed after these "pre-ophidian squamates" emerged from their burrows. This explains why snakes have a similar eye structure to one another and why this eye is different than that of other animals. Boids have the 'snake-eye', and not a left lung or eyelids. From these point it is evident that boids evolved from the same squamates as other snakes did, however they evolved less, so they are more primitive. I suppose that the 'advanced snake line' could possibly have existed before the 'boid line'. If I had the initiative I'd dig around the Internet for fossil records to provide dates; but I don't.

Cam

Edit: The definition of primitive:
From http://dictionary.reference.com/search?r=2&q=primitive
Biology. Occurring in or characteristic of an early stage of development or evolution.
That's a boa my friend.

[Double J]

It is doubtful that there was a seperate "advanced snake line" that evolved convergently and seperately from the more primitive snakes. There are far too many derived traits that it would be unlikely that a seperate evolutionary line from the original snakes would have yielded them.

Primitive..... this is often a loaded term..... it works well for things on a biological basis... but runs into trouble when used on a cultural level. That said... primitive seems to have a stigma attached to it. Why is primitive undesirable when referred to on a biological level? These "primitive" animals have had to change "relatively" little over the course of millions of years.... I consider this to be rather successful. In terms of evolution, if there is little pressure to change, little change will occur other than for reasons of genetic drift and genetic isolation. What makes colubrids, elapids, and vipers so different from boids and pythons is that the evolutionary split occurred so long ago.... 50+ million years of divergent evolution will yield a lot of things, and that is why we have such a wonderful amount of diversity with respect to snakes.

Now for Jimmy..... boas and pythons aren' exactly "paint fresh" Instead, they bear much resemblance to the earliest snakes.... the fossil record shows it... and I beleive fossils show that the first snakes came about in the neighborhood of 55-70 million years ago... though I cannot remember the number exactly. Let's not forget, these earliest forms are responsible for everything today. Snakes simply diverged very early on as there seems to have been a number of niches to fill in after the extinction of the dinosaurs, not to mention whatever else went with them. This is why we have such a rich diversity today. So, you could say that snakes came about in the right place at the right time geologically speaking.... exploited whatever niches were available (there seems to have been a lot of them), and time and evolution did the rest to give us the current level of diversity. Though of course, this is simplified.
I am at the Porter U of W library as I am typing this... perhaps I will dig up a paper on the subject.

Double J

[CamHanna]

It is doubtful that there was a seperate "advanced snake line" that evolved convergently from the more primitive snakes. There are far too many derived traits that it would be unlikely that a seperate evolutionary line from the original snakes would have yielded them.

Somewhere in ophidian evolution boids and advanced snakes diverged. By "advanced snake line" I meant the snakes that eventially, after this divergence, became colubrids, vipers, elapids and so on. I did not mean to imply that Henophids and Xenophids evolved entirely seperatly.

Cam

[Double J]

Ok.. thanks Cam.. I have re-read what you have originally posted, and realized I misread it originally :)

Sorry about the confusion.

Double J

[JimmyDavid]

[QUOTE]
[B]When an ancient species performs these changes does it not become a modern species?

Quite right, and that's my point.
Notice that a useless trait goes away much faster than a usefull one. What good
does it do having remains of leg bones in a snakes body? If boids are so old, they would have had more than enough time to get rid of those, wich proves that they could have "parted" from lizards not that long ago.
A very usefull trait like having venom, could be gainned much faster since it's directly connected to survival.

[Removed_2815]

Originally posted by JimmyDavid
What good does it do having remains of leg bones in a snakes body?
Vestigial spurs are used during courtship; they are still important anatomical features that have not been lost during evolution.
If females are more receptive to males who actively use their vestigial spurs to initiate copulation, then males who do this will be better able to pass on their genes. The offspring will be that much more likely to also have these vestigial spurs and utilise them during courtship. Thus, this anatomical feature should be retained indefinitely.
Cheers,
Ryan

[Removed_2815]

double post

[Double J]

Originally posted by JimmyDavid
Notice that a useless trait goes away much faster than a usefull one. What good
does it do having remains of leg bones in a snakes body? If boids are so old, they would have had more than enough time to get rid of those, wich proves that they could have "parted" from lizards not that long ago.
A very usefull trait like having venom, could be gainned much faster since it's directly connected to survival.

The thing here is.. that if there is no *selective pressure* to losing a body part, there is no immediate necessity to get rid of it. If a vestigial or useless trait has no affect on fitness, then there is no pressure to lose it, and therefore animals that have it are able to reproduce and pass on the genetic material that expresses this useless trait or vestigial body part. Simply because a body part is useless does not always mean that animals with it will be selected out if it has no immediate disadvantage. Thus, since a vestigial body part may not "do any good"... if it does no harm, there is no pressure to select it out.

As Ryan pointed out, there has actually been a selective pressure *to keep* an otherwise vestigial body part in the case of pythons, as females are generally more receptive to makes using their vestigial spurs. Though this trait is not "directly related to survival," it has proven to be important for breeding nonethless.

Evolution is a beautiful thing.

[JimmyDavid]

Double j, i'll have to disagree there. The first rule of evolution is: USE IT OR LOSE IT.
Anyway, why is it that colubrids have no spurs? Wouldn't came IN HANDY as well for courtship?

Katt, i want you to read your own post v-e-r-y s-l-o-w-ly to yourself. Can you see the logic flaw there, yet? Shouldn't it be the other way around?

[Removed_2815]

Originally posted by JimmyDavid
Double j, i'll have to disagree there. The first rule of evolution is: USE IT OR LOSE IT.
But primitive snakes do use their vestigial spurs, and it would appear that there is a selective pressure favouring the spurs (if females are, in fact, more receptive to mates that use them to initiate copulation). They "use it"; hence they will not "lose it" until such an appendage no longer confers a selective advantage upon the user.
Cheers,
Ryan

[Removed_2815]

Originally posted by JimmyDavid
Anyway, why is it that colubrids have no spurs? Wouldn't came IN HANDY as well for courtship?
This is the point of your original post, isn't it? Colubrids are more "advanced," they have evolved different characteristics that set them apart from their primitive counterparts. Not all characteristics are universal across a taxon; colubrids may be the result of when such an appendage no longer conferred a selective advantage upon the user. Hence, they did not "use it" so they were destined to "lose it."
Cheers,
Ryan

[Double J]

Originally posted by JimmyDavid
Double j, i'll have to disagree there. The first rule of evolution is: USE IT OR LOSE IT.


Sorry, you are wrong here.

This is a common misconception that is not entirely true. Evolution is all about selective pressures. Adaptation then is a change in structure or behaviour, based on genetics to respond to an environmental pressure or stressor.

If there is no pressure to have or get rid of something, then there will be no sexual or environmental selection of individuals in that direction. Often traits that are neither advantageous nor detrimental are lost due to genetic drift, or that there is no pressure to keep that trait, so it slowly wanes out.

Still, I can name off a laundry list of unnecessary features of any number of animals, but they still have them because it is NOT ADVANTAGEOUS to get rid of them even though it is not advatageous to keep them either. If a trait does not result in death before reproduction, or prevent reproduction due to undesirability to mates, the genetic material that expresses that trait will be passed on and will likely expressed in the offspring in many cases.

Double J

[spidergecko]

Originally posted by JimmyDavid
Double j, i'll have to disagree there. The first rule of evolution is: USE IT OR LOSE IT.

That is most definitely not true. Species can carry vestigal and useless pieces for their entire existence. The first rule of evolution is: IF IT KILLS YOU BEFORE YOU CAN REPRODUCE, YOU LOSE IT.

[Removed_2815]

Here's a prime example: the vermiform appendix. There's no selective pressure for or against this vestigial process, yet we still have it. Perhaps if we weren't so medically advanced as a species, then there would be the selective pressure of ruptured appendices causing septicaemia and death in people before reproductive age; however appendicitis is hardly a selective pressure today. Things like this may eventually regress or entirely disappear, but until having an appendix negatively affects a person's genetic fitness, it's regression would simply be due to a serious of random mutations (though I don't think the human race is going to survive much longer, evolutionarily speaking ;)).
Cheers,
Ryan

[Removed_2815]

Originally posted by spidergecko
IF IT KILLS YOU BEFORE YOU CAN REPRODUCE, YOU LOSE IT.
Though you won't find this one-liner in textbooks, I like this rule since it just about sums it up...
Ryan

[Double J]

Originally posted by spidergecko
IF IT KILLS YOU BEFORE YOU CAN REPRODUCE, YOU LOSE IT.

Short, sweet, and to the point. Bravo!

[JimmyDavid]

WRONG!
If i don't put my muscles into any kind of effort, they will srink and become smaller. Sure, there's no reason for them to develop but there's also no pressure for it to shrink. Still they do.
The rest of the body follows the same principle.

[Removed_2815]

They shrink because of atrophy, this is a physiological response and has absolutely nothing to do with evolution. You haven't changed your genome and your offspring won't have small muscles because of this.
Ryan

[Double J]

Originally posted by JimmyDavid
WRONG!
If i don't put my muscles into any kind of effort, they will srink and become smaller. Sure, there's no reason for them to develop but there's also no pressure for it to shrink. Still they do.
The rest of the body follows the same principle.

Actually, there is pressure to use your muscles. If you never used your muscles, they would not develop, they would go into atrophy, and you could not get up to eat, and you certainly could reproduce. Thus, there certainly is a selective pressure to use them..... you cannot survive if you do not use them. Without muscles, we cannot move, escape from predators, eat, or reproduce. They are necessary for survival, and we, as all vertebrates have them, and will keep them.

[JimmyDavid]

Originally posted by Double J
[B]Actually, there is pressure to use your muscles.

And if you don't use them, will it hurt to have them strong anyway? I can't see what the body gains by getting rid of muscle?! That was my point when i said that NOT USING is pressure enough to lose.
Double J, i think it goes deeper than that. Your genes affect you and you affect your genes (but in a small percentage, that is not visible in a single generation). That's Darwin's theory. If you spend a life-time running around you will develop strong legs, your genetic sistem will adapt to a certain level, and your children will benefict from that and so on. But the changes will only be visible after many generations.
If it was just about passing on what you got, we would still be stuck as the first carbonic creatures that existed because how could you ever become something different? (duh) .
Some people sugest spontaneous mutations to disregard Darwin, but (although it can happen) it's just dumb.

[Removed_2815]

Originally posted by JimmyDavid
i think it goes deeper than that. Your genes affect you and you affect your genes (but in a small percentage, that is not visible in a single generation). That's Darwin's theory. If you spend a life-time running around you will develop strong legs, your genetic sistem will adapt to a certain level, and your children will benefict from that and so on. But the changes will only be visible after many generations.
This is way off base. Yes, your genes affect you, but you definitely do not affect your genes. Darwin would be appalled to have such words put into his mouth...

If you spend a life time running around, then yes, you as the individual would have stronger legs - this is a physiological response. Your "genetic system" certainly will not adapt as this suggests something is changing genetically, which simply is not the case. Your children will not benefit from your strong legs, since in your example, your legs only got strong from running around for a life-time, and not something that developed as a result of a selective pressure.
If strong legs were a selective advantage, then people with strong legs would face a selection pressure in which those that are most genetically fit, in terms of strong legs, will survive. This is survival of the fittest and this is Darwin's theory of natural selection.

Evolution is "simply" based on a serious of random mutations that either confer a selective advantage or disadvantage on the organism and, due to a variety of selective pressures, the trait is either selected for or against (running around for no reason other than to develop strong legs will not skew evolution into producing a humanoid species with overly strong legs; unless your talking about artificial selection).

Cheers,
Ryan

[JimmyDavid]

RMBolton, if that were true, a species would NEVER turn into another species.
Explain to me: if you don't affect your genes, how come we didn't get stuck as the first life forms around?
By the way, How can you tell that for sure? Do you have info on stuff that puzzles even the greatest scientists?

[Removed_2815]

Originally posted by JimmyDavid
If it was just about passing on what you got, we would still be stuck as the first carbonic creatures that existed because how could you ever become something different? (duh) .
It is all about passing on what you've got, because that's all you have. I'm not sure how much you know about biology, but I'm assuming you know about random genetic mutations. If not, this is merely a natural event whereby a mutation in an organism’s genome arises. Without random mutations then, yes, an organism could never become something different. Fortunately, natural mutation is common and frequent (relatively speaking) when you take into account probabilities of transcription error, and relate this over evolutionary time.

Look at certain penicillin-resistant bacteria for example, this is evolution at an accelerated pace. Through a random genetic mutation, some bacteria are able to secrete an enzyme known as penicillinase, which inactivates penicillin by cleaving the amide bond of its beta-lactam ring. You can imagine how these resistant bacteria would flourish since non-resistant bacteria are destroyed by penicillin, leaving only the resistant strain to reproduce.

Originally posted by JimmyDavid
Some people suggest spontaneous mutations to disregard Darwin, but (although it can happen) it's just dumb.
I'm not sure what you mean here. Random mutations are the backbone of Darwin's theory. For there to be natural selection, there has to be variation in the population. Random mutations are the source of this variation.

Ryan

[Removed_2815]

Originally posted by JimmyDavid
RMBolton, if that were true, a species would NEVER turn into another species.
Explain to me: if you don't affect your genes, how come we didn't get stuck as the first life forms around?
By the way, How can you tell that for sure? Do you have info on stuff that puzzles even the greatest scientists?
Random mutations, natural selection, and evolution are how organisms speciate, this is basic biology.
Evolution is taught in grade school, the "greatest scientists" aren't puzzled...
I suggest you pick up "On The Origin of Species" and an introductory text on Biology, read them cover to cover because I think you're missing some background biological knowledge. That's probably your best place to start.

Cheers,
Ryan

[JimmyDavid]

Not quite. Darwin said mutations occur but never that they were reponsible for the history of evolution. Adaptation was! And that's where the chain of thoughts goes apart among scientists. Some blame mutations on everything, others say life is flexible up the genetic level. My friend, nothing is proven and we can only speculate, that's why i posted "i THINK it goes deeper than that" and didn't get arrogant enough to impose the theory i lean to.

It's clear that you go with the mutation theory (i respect that), i go more along genetic flexibility. Maybe in 1000 years, when we know all about genetics, we can tell for sure wether or not genes are flexible. As for now, i go with it because it makes sense to me.

[Removed_2815]

There's only one theory of evolution.
Adaptation is a result of genetic mutation. There is no dichotomy in theories. Adaptation is an alteration or adjustment in an organism in response to its environment, brought about by selective pressures acting on genetic variation. This is based on mutation. I can't say this any clearer than I already have.

Evolution is just a theory (so they say) but the aspects of evolution are based on solid science, there are no theories within theories. Darwin knew that there was something hereditary that was causing the variation in his finches, he just didn't know what (simply because the discovery of DNA and the study of genetics occurred long after his death).

Not sure what you mean by "genetic flexibility" but I think it has something to do with your strong leg example, which is a ludicrously incorrect example. One of the very first things that people are taught when they decide to study biology is that an individual's genome is immutable. The individual cannot physically change his genes by developing strong legs, this is undeniable fact. My children should be born with 5 fingers on each hand even if I decide to cut mine off.

Ryan

[spidergecko]

Using the "strong legs" example, selective pressure would favour those organisms that require strong legs for survival. The organisms with the weakest legs will be removed from the pool sooner than strong legged ones. The strong legged organisms will proliferate. The weakest of these strong legged organisms have a higher probability of getting killed so in time, only the strongest legged organism will survive. The difference between each organism is a small difference in genetic makeup. Recombination ensures that every individual in a species is potentially different than the others. Those genetic mutations either kill new mutants or enforce the gene pool of current individuals.

If you continually chop the tails off of mice as they are born, 1 million years from now the mice will still produce tailed-offspring (assuming no other mutation takes place).

[CamHanna]

Originally posted by JimmyDavid
Darwin said mutations occur but never that they were reponsible for the history of evolution. Adaptation was!
"Adaptation", in this case, refers the population as a whole. A random mutation occurs at the very beginning of an individuals life, long before birth, though admittedly I don’t understand when exactly, presumably in egg or sperm cell; I’m sure Ryan will know. This individual, by virtue of this random mutation, is more genetically fit (better able to survive and reproduce) than the other individuals in the population. Thus the mutated genes are passed on to the offspring and spread throughout the population, until the entire population has this mutation. This POPULATION has now adapted, using the mutation, to react to some selective pressure. This occurs because individuals without the mutation are not as able to survive and reproduce.

Individual physical fitness, while it may affect an individuals chance of survival, is not heritable. If this physically fit individual has some genetic predetermination to be physically fit then the offspring might also have this predetermined fitness. If the physically fit individual is fit only by virtue of excessive exertion then the offspring will also need to exert themselves excessively to become as physically fit as their parent was. This is an individual adaptation; unless each individual in the entire population trains themselves to be physically fit then the population will not change. This is not evolution.

Mutations can occur in a living individual (ie. a tumor) but this is not in response to anything the individual has done (aside from exposing themselves to carcinogens). This mutation also occurs in only one cell and later in that cells daughter cells; it does not affect the entire “genetic system” and is thus not passed on to the offspring.

Cam

Edit: Then/Than corrections.

[JimmyDavid]

What are you talking about ? Darwin's theory has been questioned so much lately.
Another thing: How come it's an undeniable fact that genes don't change?
Scientists have only scratched the surface of what's involved in that. Nothing is "undeniable" at this point, just yet.
A mutation is a ramdom change, the chances of it to bless you with the EXACT traits you need to survive are close to nothing. How can you blame the entire history of evolution on that?

[Removed_2815]

I am having a hard time reading just what it is you're saying. I'm getting a headache trying to make sense of it all.

Originally posted by JimmyDavid
Darwin's theory has been questioned so much lately.
Darwin's theory has always been questioned; with regards to creation vs. evolution. What part of Darwin's theory is being questioned by evolutionists?

Originally posted by JimmyDavid
Another thing: How come it's an undeniable fact that genes don't change?
Genes do change, who said they don't?

Originally posted by JimmyDavid
Scientists have only scratched the surface of what's involved in that. Nothing is "undeniable" at this point, just yet.
Most of the revelations in genetics are undeniable. We're talking about biochemistry here; these biological processes obey accepted "chemical" laws and successful chemical designs are used over and over in these processes.

Originally posted by JimmyDavid
A mutation is a ramdom change, the chances of it to bless you with the EXACT traits you need to survive are close to nothing. How can you blame the entire history of evolution on that?
Evolution is blind, there is no set goal. I never proposed a teleological basis. It's all random. If you believe that there is some divine scheme then that's fine but perhaps that is why your evolutionary arguments are falling short.
Evolution is in it's essence a series of random events. Have a look at Stephen Jay Gould's work on contingency. If we were to do it all over again, there's no guarantee that a human-like creature would evolve, in fact, it's unlikely.

Cheers,
Ryan

The history of life is not necessarily progressive; it is certainly not predictable. The earth's creatures have evolved through a series of contingent and fortuitous events. - the late Stephen Jay Gould

[tdherper]

Very informative thread, JimmyDavid, you seem to not want to evolve past the fact you are mistaken.....;)

[Cake]

How come it's an undeniable fact that genes don't change
Even if you were able to change the gentic makeup of your leg muscles, by increasing thier mass and strength, this would not affect what you pass on to future generations. The genetic material that you pass on to your children is contained in your gonads. Whether it be testes or ovary. The makeup of these cells is desiganted early in development when the germ cells migrate to thier respective orgaizing regions. It is simply impossible for you to change the genetic makeup makeup of these cells via exercising. You simply play the hand you are delt and if your hand is better than the next persons, you win and get to reproduce.

JimmyDavid I think you may be misinterpreting the term genetic flexibilty to be that it applies on the level of the individual. This is not true. Genetic flexibility applies at the population level. I will attempt to show this by use of the famous example of beak size in Darwins Finches.

A population of finches has a range in beak size from small to large. The small size beaks are specialized for consuming small seeds, while the large size are specialized for consuming large seeds. Inbetween these two extremes there is a range beak sizes which corespond to being a generalist feeders which cannot consume the largest for the smallest seeds, survive by consuming the mid range in sizes. Beak size is a heritable trait. One year there is a severe drought resulting in the production of a large amount of small seeds, and only a few large ones. The finches which posses small beaks are better adapted for this environment while the birds with large beaks are not and the majority of large beaks die off. Birds in the mid range of beak size do ok but not particularily well. This results next year with more birds that posses small beaks mating and thus the genes for small beaks are passed on and not that of large beaks. There is still a representive of the large beaked population present, representing along with the few remaining midranged sized beaked birds the genetic flexibility of the population. Now as long as the food source stays some what the same, the large beaked offspring are less likely to survive to reproduce then their small beaked counterparts. The individuals with midranged beak size do decent and some do survive to reproduce, maintaining the gentetic flexibility of the population.

The population now consists of the majority being small beaked, some midrange beaked, and only a few large beaked. Further selection pressures could also affect the populations such as more moisture content in one region than another resulting in larger seeds for the larger beaked birds. Thus they geographically isolate from the small beaked birds and then become reproductively isolated, resulting in a speciation event.

[CamHanna]

Originally posted by Cake
Even if you were able to change the gentic makeup of your leg muscles, by increasing thier mass and strength, this would not affect what you pass on to future generations.
Perhaps I am misreading this quotation, but I feel obligated to point out that, while physically you can change through exercise, you cannot change your genetics. Even the "genetic makeup of your leg muscles" remains the same; the legs only change physically. You are correct, large leg muscles from exercise are non-heritable.

[Cake]

I think I may not have written that segment clearly. I intended to point out that you cannot change your gentic make up. BUT(and that is a huge BUT) if it were possible, the change would be localized and would not affect the genes included in any produced gametes.

[JimmyDavid]

RMBolton, what i said doesn't sound like divine work. It's when a a reptile happens to gain very usefull wings out of a "random" mutation that it starts to sound like that.
You have been reading too much x-men comics.

[CamHanna]

Sorry Cake, I just skipped right over the IF part of that statement. No hard feelings I hope.:)

[JimmyDavid]

Food for thought: If evolution depends on mutations, that means everything you GAIN needs a mutation, what about everything you lose? Are boids waiting for a mutation that finally removes bone remains from them? why did birds lose their teeth? another mutation? Why don't we have remains of scales, tails, strange bones, fangs or other strange traits from the past creatures that we once were? A handy mutation took care of all that for us?
The more i think of all that, the more i believe that you develop what you use and lose what you don't need. And for that to work, your genetics must be somewhat changed by the time you breed, otherwise there would be no species evolution only individual.

Another fact: a mutation is a flaw (physical handycap), and most of the times mutated creatures are sterile.

[Cake]

No worries CamHanna, when I read it back to myself it wasn't very clear.

[Removed_2815]

Originally posted by JimmyDavid
If evolution depends on mutations, that means everything you GAIN needs a mutation, what about everything you lose? why did birds lose their teeth? another mutation? Why don't we have remains of scales, tails, strange bones, fangs or other strange traits from the past creatures that we once were? A handy mutation took care of all that for us?
Let's see if I can yell this loud enough so that you understand: YES!!!!!!!!!! YES, to every one of your questions.
You're thinking that birds had to lose their teeth as part of some divine plan and that a "handy" mutation came along to do this for them, this is teleology and I already said that you cannot think this way if you want to discuss evolution.

We do have remains of tails, etc., we do have homologous bones to other animals, and we do have embryonic characteristics that are similar to many other species.... Jimmy, it's very difficult to argue with biologists if you have not studied the science yourself.

Originally posted by JimmyDavid
You have been reading too much x-men comics.
You call 'em X-men comics, I call 'em Biological texts and scientific literature. You'd be well advised to have a look at these comics yourself before participating in an evolutionary discussion.

As for the rest of the tripe in your last two posts, you appear to have an unyielding amount of unfounded opinions that I am not about to attempt to dissuade you of. Just do us all a favour and do a little simple research beforehand, none of us here want to take you through a crash course in biology if you're not going to listen. You might of learned something if you paid attention.

It's been fun but I think I've said all that needs to be said.

Ryan

P.S. Mutations are not "flaws" if they serve to make one better suited to his/her environment and mutations very rarely render an organism sterile.

[JimmyDavid]

You keep saing i'm bringing a religious intention to my debate (?) I think you are having issues understanding it.
Since we are talking about comics. Did you read the death 0f superman? Ever heard of Doomsday? .... Can you prove that it's impossible to create a creature that way?

[JimmyDavid]

[QUOTE][i]Originally posted by RMBolton If we were to do it all over again, there's no guarantee that a human-like creature would evolve, in fact, it's unlikely.


err...that's a stupid comment Bolton. If we started all the way from the beggining (same big-bang, spreading matter through the void in the same way, under the same laws of physics) the universe would be created as an exact copy the existant.

[CamHanna]

Originally posted by JimmyDavid
err...that's a stupid comment Bolton. If we started all the way from the beggining (same big-bang, spreading matter through the void in the same way, under the same laws of physics) the universe would be created as an exact copy the existant.

"My cat's breath smells like cat food."

[CamHanna]

Originally posted by JimmyDavid
err...that's a stupid comment Bolton. If we started all the way from the beggining (same big-bang, spreading matter through the void in the same way, under the same laws of physics) the universe would be created as an exact copy the existant.

If it all happened exactly the same way then you are correct, it would all happen exactly the same way. It is incredible unlikely though.

[spidergecko]

Originally posted by JimmyDavid err...that's a stupid comment Bolton. If we started all the way from the beggining (same big-bang, spreading matter through the void in the same way, under the same laws of physics) the universe would be created as an exact copy the existant.

If this was true we should be able to predict what the earth will look like in a million years.

I don't understand how you believe probability has no effect on the outcome of the universe.

[JimmyDavid]

That's correct. But you would need to know an infinite number of variables. That makes it impossible.
Think of it this way: when you build a domino formation you know from the moment the first domino falls, the last one has the same fate. If you build the exact same formation again, the results will again be the same, and so on. The universe works that way, only the variables are infinite.

[spidergecko]

Then I understand completely what you are saying. You believe the universe has a set path and that regardless of our belief that the universe is random, it is, in fact predetermined.

If this is true then there really is no point discussing the issue since "scientists" believe the universe is random and never duplicated.

[JimmyDavid]

You can say it's fated. Not predicted (because it's impossible) but yes fated.

[Double J]

Originally posted by JimmyDavid

You have been reading too much x-men comics.

Clearly RMBolton has been reading *textbooks*


Originally posted by JimmyDavid
If you spend a life-time running around you will develop strong legs, your genetic sistem will adapt to a certain level, and your children will benefict from that and so on. But the changes will only be visible after many generations.
If it was just about passing on what you got, we would still be stuck as the first carbonic creatures that existed because how could you ever become something different? (duh) .


Again.. this idea is incorrect, and disproven. The idea you are referring to is strikingly similar to Lamarck's theory of gemmules.
This was before the discovery of DNA and chromosomes. Essentially, Lamarck beleived that animals inherited characteristics through the transmission of gemmules, and these gemmules were affected by physiological change duting the lifespan of the animal. I will use the classic example of giraffes to illustrate how gemmules work. It is a fact, that the ancestors of giraffes were short necked animals. Lamarck then proposed that the ancestral giraffes strtched their necks out furthur and further to reach higher into the trees throughout their lifespan. This trait then, according to Lamarck, would be passed onto the progeny of these giraffes. Each generation would then stretch their necks out further, until we have the grafes of today. I think the flaw in this logic is rather clear. If traits wer passed in this fashion, then an animal that has lost a limb woud give birth to limbless babies. Thus, it is logically clear that physiological change has no efect on genetic material. Let's not forget theoodles molecular data to support this.

Let's not forget that not all evolution occurs via random mutation. Rather, adaptation often occurs as a result of extremes of variation.

[JimmyDavid]

Finally someone is bringing good points of view and not just trying to be a smartass.
double J, what you say makes sense, but still i disagree in certain things.
First, the limbless thing is not a good example. I said that you pass the traits in a slow way, taking many generations.
Someone posted that selective breeding is responsable for evolution. But for that you need 2 genetic doners. Let's say mankind had gone sterile, and
we adopted the cloning process to continue existing trough generations (only 1 doner). Would our evolution forever freeze?

[Removed_2815]

Originally posted by JimmyDavid
[QUOTE][i]err...that's a stupid comment Bolton.
That's not my comment, it's the basis of contingency. That's the essence of Gould's work.
If we went back to a random point in Earth's history, let's say, at the beginning, and allowed the tape to play again, we WOULD NOT ARRIVE AT THE SAME PLACE WE ARE NOW! We're talking about an infinite number of chance events. Perhaps you should have a chat with Simon Conway Morris, he's Gould's opponent and his ideas are almost universally discredited. I have interviewed him, you're just as annoying as he is.

The fact that you think it is a "stupid comment" just validates how little you know about biology.

Anyway, I truly feel the value of this post expired long ago. Unless you have some legitimate questions, and are willing to accept the answers for what they are, then I suggest you drop it.

Ryan

[JimmyDavid]

It would not be, assuming it's rather unlikely that the exact same conditions would be at play. But i believe we were, pass that point, talking IF it all took place the same way.

What does that have to do with Biology?

If you think i'm being annoying why are you participating in this thread?

[Removed_2815]

Originally posted by JimmyDavid
talking IF it all took place the same way.
So you're saying that if it were the same, then it would be the same... That's a heck of an insight.

[JimmyDavid]

That's exactly why i said it was a stupid comment to start with.

[Removed_2815]

Is this guy making anyone else's ears bleed?

[JimmyDavid]

Are your ears bleeding? Maybe that's because your brain is sick, pal.

[CamHanna]

You're not alone Ryan.

[JimmyDavid]

I've seen a handfull of threads being closed because of you, man. It's not that you don't bring good debate material or are short of information. It's just that, at some point, you have no more patience to listen to others and get nasty.

[HeatherRose]

I've seen a handfull of threads being closed because of you, man.

I haven't... which threads are these?

There is only so much patience one can have when someone calls their information 'stupid' and doesn't have anything substantial to counter with or prove it wrong.

That said, can we please attempt to keep it just a little more civil? This is an awesome thread, lots to think about.

[CDN-Cresties]

I have skimmed through this thread and I would just like to say that RMBolton has been correct in what he has said. Sorry JimmyDavid but you are the one who is "short on information" on this thread.

[tdherper]

JimmyDavid you are clearly lacking the knowledge or understanding of those you chose to challenge on the subject. Trying to call people out for YOUR failure to accept the facts clearly shows as I stated before that your views are not "evolving" with the information being afforded to you.

I have found this thread very informative and educational and it's your attitude that is poisoning the thread. If you cannot be persuaded by the facts presented to you, I'm affraid your understanding of the subject is "fated" to be.....

[spidergecko]

In JimmyDavid's defence, he does have a belief that the universe is fated. This means probability does not exist and everything that happens was meant to happen. Things don't change based on their environment, they change because the fates say they will. Following this logic, everything he writes make complete sense. I can't say I agree or that the majority of people agree, but following his logic, it does make sense.

[Lioness]

i dont know much about this kinda stuff yet...but man, jimmy, u start the best topics:D

[lostwithin]

JimmyDavid, I just read over this entire post, and what I got out of it is you began a topic with a ligament question. Which I belive has been answered but incase it hasn't.

You are looking at it a bit incorrectly, the reason Boids are considered primitive is because they bare the closest resemblance to the ancestral snakes. they have been evolving just as long as colubrid species they just have not gone through as much change. Its not like coloubrids started evolving moved through the "boid phase" and into a more advanced species before boids began evolving. they simply branched off for whatever reason and evolved at a different rate/ different direction. then boids did.

If it helps try to look at it in human/chimp turns. both are now considered to have evolved from a common ancestor. Chimps bare a closer resemblance to that ancestor, but they have been evolving for the same amount of time. they just have done so in a different way. Technically neither is any older then the other. But chimps would be considered primitive because of there closer resemblance to that ancestor.

In the end I would suggest doing much more research into evolution You seem to have a few key points to learn before you should argue anything. theirs nothing wrong with being wrong and being corrected but to argue an incorrect point just makes you look foolish.


Devon

[Jeff_Favelle]

JimmyDavid, you're giving me a headache man. If I didn't have a head that was about to explode because of your "genetics" breakdowns, I could refer you to a couple of books that could explain it to you.

1) The smallest unit of life that can evolve is a POPULATION!!! The individual cannot evolve and events that happen to it (ie making your legs smaller) is NOT HEREDITARY. It does NOT change your genotype.

2) Boas are the most primitive of SNAKES. No one said they were a pimitive animal. But if you had two lines of snakes that had legs eons ago, and one line had evolved to get rid of them COMPLETELY and another line still had working remnants of legs, which line is the MORE primitive??? Obvious, no? They call boids primitive in RELATION to other snakes, not to other animal groups.

3) Evolution takes a LONG time (there are exceptions) and happens as the result of selective pressures (ie THE HABITAT CHANGES!) affecting who is successful and who is not ( so that they can pass on their genes).

I do hope you pick up a book on this, because you are close, but you are confused on a lot of the basics.

Cheers guys. Good discussion.

[JimmyDavid]

Seems that the part where most disagree with me is about genetic flexibility, where i said it's possible for a creature to pass some transformed genetic data to it's next generation.
While i understand this is a herp site, not a Biology convention, i was expecting you all to know that such is more than known to happen. And more,
evolution does not depend on selective breeding, like someone pointed out here.
Perhaps the best example is the virus.
The virus is a sexless creature (there are no males or females) and their next generation takes only one doner, so you could say they are supposed to be an exact copy of the "parent". But yet they change. Everytime a virus endures a challenge (drugs, for example) they become stronger and they change at genetic level, that's why our body can't recognize it anymore and vaccines stop working.
The next "bloodline" carries the alterations performed by their "fathers" and that's why we have a new flu-type almost every winter. This would never be possible if the genetic content passed on didn't include the modifications made.

[tdherper]

:zi:

[lostwithin]

Nice point JimmyDavid, but there is a reason the a virus falls under a separate category all together. they are not part of the "super kingdom" of Eukariota, which contains animals, plants, fungi , and protozoa.

Your comparison would be like be saying since you can vaporize a container of mercury but it is still mercury just in another form. that is a proven fact, so obviously I could vaporize my Ball python and it would still be a ball python just in a gaseous form.

Now how ridiculous does that sound ? again I will suggest that you do more research before arguing a point and making yourself look foolish.


Devon

[JimmyDavid]

Mercury is a physical element, a Virus is a living cell with a dna chain as complex as any other creature's. I don't see any connection.

[lostwithin]

No as a matter of fact a virus is a particle, more specifically a nucleic acid with a protein shell.

Now again I will suggest you take the time to do some research before you argue an incorrect point then back it up with incorrect information.

Devon

[Removed_2815]

Originally posted by JimmyDavid
a Virus is a living cell with a dna chain as complex as any other creature's.
You're joking, right?

[JimmyDavid]

Let's see: In school i was told that a virus lives, reproduces and dies. That makes it a living creature (the fact alone that it reproduces means it has a dna chain) but now i'm learning it's all wrong. Why did i listen to my teachers? should have known better...

[JimmyDavid]

Originally posted by lostwithin
No as a matter of fact a virus is a particle, more specifically a nucleic acid with a protein shell.


I said a virus is a living cell, you say it's not and then you DESCRIBE one. Go figure it...

Ok, drop the virus example. There are deep-sea creatures that follow the same reproduction system. No male or females. Is it possible that these creatures never evolved and never will? please...

[lostwithin]

the fact that it reproduces or multiplies, does not mean it has a DNA chain. In fact wether viruses are even considered alive or not is still debated. Maybe your teachers were wrong maybe you just weren't listening. Either way all the information can easily be found in any high school text, or all over the Internet. you just have to take the time to read rather then make things up.

Devon

[JimmyDavid]

Originally posted by lostwithin
In fact wether viruses are even considered alive or not is still debated.



If it's even being debated how come you're so sure of everything you say?

[JimmyDavid]

Originally posted by lostwithin
[B] Maybe your teachers were wrong

I have nothing more to say...

[spidergecko]

Parasitic microorganisms become tolerant and immune to antibiotics because they reproduce quickly, and undergo regular mutation. Those parasites in the population that are able to withstand the treatment long enough to reproduce, because of a slight difference in genetic make up, are able to pass the difference in code to consecutive generations. It has nothing to do with getting used to the antibiotic.

[Removed_2815]

A virus is neither a cell nor is it considered living.
The closest X-men comic that I have at hand is my "Fundamentals of Biochemistry" by Voet, D., Voet, J.G., and C.W. Pratt. 2002. So it will have to do:
"Viruses are much simpler entities than cells and are not classified as living because they lack the metabolic apparatus to reproduce outside their host cells."

"Virus: A nonliving entity that co-opts the metabolism of a host cell to reproduce."

[lostwithin]

that is not the description of a cell at all. you really are having trouble with this concept of not arguing points you don't understand , and the fact that there are hermaphrodite animals does not mean they follow the same reproductive behaviors at all. and if you are speaking of asexual animals that again is a completely different mod of reproduction. PLEASE take the time to look things up , you are just tossing random facts out there and trying to make them match your needs, it doesn't work that way. it just makes you look ridiculous.

Devon

[Removed_2815]

Originally posted by JimmyDavid
I have nothing more to say...
Dost mine eyes deceive me?

[lostwithin]

Using your teachers as an excuse is very childish. there is nothing stopping you from learning things on your own. Your just Wrong on many many different points, get over it. Learn the right things and then participate in a debate if your like.

Devon

[JimmyDavid]

News to you all: Viruses DO have dna. That's exactly how they attack cells and bacteria, by inserting their dna into them.

RMBolton said a virus is a non-living creature, Lostwithin said there's debate aroud it. Guys, get your act together.

[lostwithin]

If it's even being debated how come you're so sure of everything you say?

I have only relayed facts that are well known, non of which have anything to do with viruses being alive or not. there structure and the fact that they are of a separate super kingdom would still remain the same regardless of the definition of a living organism.

Devon

[lostwithin]

JimmyDavid, I did not say a virus DID NOT have DNA, I said they were composed of a nucleic acid, which could be either a form of DNA or RNA. Some have one some have the other.

And what RMbolten says is his right. They do not fit the description of a living organism, I simply chose not to take a stance on the matter.

And if anyone should get there act together it should be you , you are all over the place in this thread. You are wrong get over it, learn from it and live life a little be more informed then when the post began.

Devon.

[Removed_2815]

Originally posted by JimmyDavid
RMBolton said a virus is a non-living creature, Lostwithin said there's debate aroud it. Guys, get your act together.
:rolleyes:

The only debate comes from people who want to stretch the traditional "Characteristics of Life" so that it encompasses viruses.
There are specific characteristics of life that something must usually possess to be considered living. The characteristics of life (cellular organization, sensitivity, growth, development, reproduction, regulation, homeostasis, heredity, etc.) are not all satisfied by viruses, save for reproduction. But viruses cannot reproduce on their own. This is why it is generally accepted that viruses are not living. But just like with everything else in science, there are JimmyDavid-type people who will simply argue for argument's sake and thus, there is always controversy.

Close to 100% of the texts and literature out there regard viruses as non-living entities.

Ryan

[lostwithin]

I'll second what RMBolton said, and from what I have learned both in school, and through research I would have to agree they are non living. I gave credit to the debate for the sake of JimmyDavid's argument to simplify things. It didn't work lol.

Devon

[Removed_2815]

I don't have a concrete opinion on the matter either, really. I'm a biologist, not specifically a virologist. I just thought a quote from a recent text would help show that the vast majority of the scientific community consider viruses to be non-living. For JimmyDavid to say "a Virus is a living cell" is what prompted the response.

Ryan

[Double J]

Originally posted by JimmyDavid
Let's see: In school i was told that a virus lives, reproduces and dies. That makes it a living creature

A virus does not reproduce on its own. It neither goes through the processes of mitosis or meiosis.

Originally posted by JimmyDavid

I said a virus is a living cell

A virus is not a cell, nor does it bear any reseblance to anything cellular. It has no nucleus, not to mention about a billion other differences.


Originally posted by JimmyDavid

(the fact alone that it reproduces means it has a dna chain) but now i'm learning it's all wrong. Why did i listen to my teachers? should have known better...


Viruses completely lack DNA. Theie genetic material is composed of RNA.
The structure of DNA is not that of a chain, rather its structure is that of a double helix.

No disrespect Jimmy, but it sounds lke you were not paying too much attention to your teachers after all.



Jimmy, though I lack the intention of any disrespect, please take another look through some biology texts.
Case in point:

Originally posted by JimmyDavid
News to you all: Viruses DO have dna. That's exactly how they attack cells and bacteria, by inserting their dna into them.

Again, viruses contain no DNA whatsoever, as their genetic material is composed of RNA alone. Clearly, you need to do some more reading.


Keep in mind, I have no problem posting references for everything I have stated in these posts.

[nita]

Interesting discussion, I have to agree with every one but JimmyDavid. Biology was my fav in school and although I'm not as informed as RMBolton and others here I do know that we can not change our DNA by affecting physical change to myself, me going tanning to have a darker complextion will not mean my children will be born darker skinned. Lots of great info in this thread though, Thanks RMBolton, Double J, and Lostwithin.

[JimmyDavid]

Wow, i just got home and i'm surprised to see this thread is still going. :)

I would like to point some other things that discourage the theory of evolution through random mutations.
To begin with, a mutation isn't even supposed to happen, when it does it's because something went wrong with the dna copying. Though i don't believe in higher designs, i also can't image nature being so incorrect that leaves evolution dependant on mistakes.
But it gets worse; since a mutation is a mistake to start with, it is more lickely that it creates a defective creature other than an enhanced one. STILL assuming it does - notice that chances are growing thinner - and an animal is born with traits that set him superior to the rest of it's species, he still has to breed - chances are growing even thinner because in nature not all animals get to be successfull breeders- but the question is : who will be his partner? Since he is unique, he will have to breed with a REGULAR specimen and therefore spoil those rare genetics (back to zero). If he (By a Long shot) has brothers or sisters that received the same traits, they can breed but will create an inbreed generation that will, most lickely, be unhealthy or even sterile.
The chances of a mutant avoiding premature extinction are slim, much less replacing the entire mother-species.

[CamHanna]

Posted by JimmyDavid
To begin with, a mutation isn't even supposed to happen, when it does it's because something went wrong with the dna copying. Though i don't believe in higher designs, i also can't image nature being so incorrect that leaves evolution dependant on mistakes.

"There is nothing either good or bad, but thinking makes it so." Most mutations are unsuccessful, but some, by some lucky coincidence, are beneficial.

Posted by JimmyDavid
chances are growing even thinner because in nature not all animals get to be successfull breeders
This mutated animal has some mutation to help it mature into a successful breeder. If it doesn't work then no big deal, another mutation will come along, then another and another after that. Eventually one of these mutations is bound to find it's way into the main population; that's evolution. This takes tens of thousands of generations. Burbrink (2002) indicates that speciation can occur after 40 000 generations (he may have been citing someone else, I'm not going to look it up).

Posted by JimmyDavid
Since he is unique, he will have to breed with a REGULAR specimen and therefore spoil those rare genetics (back to zero).
A mutation is, by definition, heritable. Albino ball pythons are mutants. They breed with normals to produce hets and these hets breed together to produce albinos.

Winston Churchill once said: "A fanatic is one who can't change his mind and won't change the subject."

Cam

[JimmyDavid]

The fanatic comment is out of line! Why is it that after every constructive statement (wich is good for the debate) you feel the need to "spice" it up with an attack?

[lostwithin]

JimmyDavid,

You have shown over and over that you are trying to discuss a topic that is way beyond your understanding.

The reason you are having trouble with this is you are trying to use very limited bits of information to form an entire complex theory , and to make it worse you aren't even right about the few facts you are trying too use. Your all over the place with your information and all in all you are just plain confused.

Now who are you to say a mutation is not supposed to happen. It is a perfect method of keeping diversity in a population allowing it to have the means necessary to adapt to an ever changing environment.

So since you refuse to listen to anything anyone is says go online and look it all up yourself. and don't just fill in blank spots with guess work.

Or you could just prove the entire scientific community wrong and evolve yourself some wings.


Good luck with whichever choice you make.

Cam,
great quote.


Devon

[CamHanna]

Sorry mate. I found that quotation today and thought it clever. This was only a convenient place to share it. I assure you it's all in jest not personal. You can assume that any 'attack' I make against anyone is made with a ':)' in mind. No hard feelings I hope.

Cam

[JimmyDavid]

Ok. No harm done, i guess. :)

[tdherper]

:zi:

[spidergecko]

Originally posted by lostwithin
The reason you are having trouble with this is you are trying to use very limited bits of information to form an entire complex theory , and to make it worse you aren't even right about the few facts you are trying too use.

The theory isn't even complicated. It is very simple. However, I think JimmyDavid is missing a key idea.

"Nature is not trying to reach perfection. Nature is trying to reach equilibrium."

As for the "thinning genetics" issue: mutations are carried to subsequent generations. If a mutant survives to breed, more animals will carry the mutation. In time, more individuals in the population will carry the mutation and the probability of two mutant individuals crossing increases. Mutations are NOT bad! They just ... happen.

[JimmyDavid]

CamHanna, your justification through "hets" is a good try and smart thinking as well, but in the end justifies nothing. And the fact that you used a ball python as an example is way too convinient ;) , why didn't you choose a species that produces only one kid per breeding?
A het is not the real thing, only a child that carries part of the genes from both fathers (it's possible to recover traits from either parent) but you make it sound like it's easy and it's not. It works in captivity because we select specimens to breed, in nature it all happens randomly. And your "het kid" would be nothing but a watered-down form of his father; from that point on consecutive breedings with regular specimens would only serve to keep watering down those special traits even more. Unless he could breed with another het, but there would be none. Also unless he could breed directly with his father (that's a long shot, and still the offspring would be inbreed ).
But your point was good, it really was.
I don't know how manny of you have info about the Chaos theory, but the more you learn about it, the more you suspect "convenient" probabilities like beneficial mutations.


Ps _ Also take in consideration that there's a natural tendency in species to breed with familiar looking specimens. That's why Hybrids are rare to obtain. A
creature that looks or acts different within a population probably will never get an interested breeding partner. Once again chances for a mutant to keep going don't look good.



Food for thought: You guys make it sound easy that a new species rises from a single specimen; scientists consider a species is doomed when numbers are reduced to a few thousands. Compare the odds.....

[Cake]

A het is not the real thing, only a child that carries part of the genes from both fathers (it's possible to recover traits from either parent) but you make it sound like it's easy and it's not. It works in captivity because we select specimens to breed, in nature it all happens randomly. And your "het kid" would be nothing but a watered-down form of his father; from that point on consecutive breedings with regular specimens would only serve to keep watering down those special traits even more. Unless he could breed with another het, but there would be none.

Lets not forget that there is more to genetics then simple recessive traits. there are also co-dom, dom, and sex linked traits. Just to say the ones that came to my head quickely. Your watered down theroy works well when you consider the trait to be neither benificial nor deleterious. If the trait is beneficial it will improve the individuals reproductive success.

I don't know how manny of you have info about the Chaos theory, but the more you learn about it, the more you suspect "convenient" probabilities like beneficial mutations.
Does this not go directly against what you were saying earlier in this thread that if evolution were to happen, it would come to the same end result. The probability that the series of random mutations that happened to result in the human race, are extremely unlikely to occur in the same sequence again.

[Removed_2815]

Originally posted by JimmyDavid
in nature it all happens randomly.
I thought it was all "fated?"
http://wealthsmith.com/animated_man_digging_hole.gif

[JimmyDavid]

It's all fated, but random as far as our understanding goes.
If the fate of the world is to be destroyed by a comet, it is coming our way already and we just don't know it. In fact, it's course could be traced back since the dawn of earth. But we can only play with information that we have, so everything is random FOR US.

[tdherper]

:zi:

[JimmyDavid]

Hehe, very mature, tdherper.
Your smiley looks cool, though.

[tdherper]

It's a weeble... "weebles wobble, but they WONT fall down!" :zi:

[tdherper]

PS It was fated when they wrote that jingle .... it would apply to this situation.....they/we just didn't know it at the time.....:confused:

[JimmyDavid]

hahahaha, you made my day. Great humor.
(and so very right) ;)

[Double J]

Originally posted by JimmyDavid

A het is not the real thing


Jimmy.... a heterozygous individual is absolutely a real thing. Heterozygous, on a most basic level, this refers to the condition of one carrying two alleles of the same gene. In the case of a heterozygous individual, you can have either allele being dominant and/or recessive with the expression of one or the other, or in some cases, a heterozygous individual may express a sort of blending of the traits of the alleles on that gene. Again, this is incredibly simplified.
A het is not a real thing?????? Jimmy.... again this shows how poor your knowledge of genetics and evolution is. READ A TEXTBOOK!!!!!!! Organisms that are heterozygous exist! This is not a man-made model, it is real!


Originally posted by JimmyDavid

I don't know how manny of you have info about the Chaos theory, but the more you learn about it, the more you suspect "convenient" probabilities like beneficial mutations.

Ps _ Also take in consideration that there's a natural tendency in species to breed with familiar looking specimens. That's why Hybrids are rare to obtain. A
creature that looks or acts different within a population probably will never get an interested breeding partner. Once again chances for a mutant to keep going don't look good.

Food for thought: You guys make it sound easy that a new species rises from a single specimen; scientists consider a species is doomed when numbers are reduced to a few thousands. Compare the odds.....


Jimmy... I cannot stress this enough.. so I will type it in caps this time...

NOT ALL ADAPTATION AND/OR EVOLUTION IS A RESULT OF RANDOM MUTATION!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I will say it one more time so it sinks in:

NOT ALL ADAPTATION AND/OR EVOLUTION IS A RESULT OF RANDOM MUTATION!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Okay, read this carefully. There is a range of varation and variability for any number of traits in a population. Thus, going back to giraffes in an extremely simplified model.... in the process of their evolution, some giraffes have longer necks than others. Therefore, you can have animals of similar general body size, with varying lengths of their necks. Giraffes A, B, C, and D have necks ranging from say 7-9 feet. Giraffes E, F, G, and H have necks that range from 4-7 feet. We will say then, that all of these animals are within a few months of each other in terms of age, and are within a few months of sexual maturity. To continue, perhaps we can now imagine that the past few years have been realtively prosperous for the giraffes in terms of reproduction, so the population has risen by X percent. However, the carrying capacity of the savannah and the acacia trees which they feed on cannot support this many animals. As this increase in population feeds, the lower leaves on the acacias have thinned out. There are then far fewer leaves on the lower portions of these trees. However, giraffes A through D, through the simpleness of species variability, (they are fortunate in this case of course) to have necks that are a few feet longer than individuals E through H. Now, there is a shortage of low-growing acacia trees from heavy feeding from a high population. Much of the lower growth is now gone. Giraffes A through D have little trouble reaching higher into the acacias for leaves. Giraffes E through H however, are having trouble finding food at this point, and have to wander farther and wider for food... though giraffe H may be able to scrounge a little more than the others on the lower end of the neck length range as his neck is in the middle of the range (7 feet). Thus, giraffes E, F, and G have starved because they could not reach higher into the trees, while giraffes A through D, as well as maybe E are able to live through this harder season, outcompete these shorter necked individuals, and reproduce a few months later. So, in this model, the giraffes with slightly longer necks have been selected for, as they have had an edge in this case of exploiting a resource like food. They then, have passed on the genetics for slightly longer necks. Again, this is not a result of mutation!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Rather it is a result of selection of individuals at one extreme of a *range of variability.* This does work both ways as well. There is a limit to how beneficial a long neck can be, and this will often be controlled as well. Now, let's not forget that there will still be variation in subsequent generations, though it will tend to be to the higher necked end of the spectrum. However, this is controlled as well. This process is called NEGATIVE FEEDBACK. This works to keep variability within a range. Giraffes with necks that were too long may have had problems drinking water early one, or may have had problems running, or even skeletal or muscular problems that would lead to death before reproduction. Thus, the biology of the animal itself may limit the range of variability as well. And of course, the animals with the shorter necks on the extreme end of variability may have problems feeding at a young age, and then may not reach reproductive age. However, this variability with a low end of the spectrum is beneficial as well. For some reason, if there was a beneficial reason to have a shorter neck for feeding on the ground.... say acacia trees were wiped ourt by some sort of disease or climatic change, there is the variability within the giraffe population to go back to a shorter necked population if need be.
This does not always work though, though varaibility allows you to deal with a change, not enough variability, or a change that occurs too fast in the environment may lead to extinction.

I hope this simple model allows you to realize that not all adaptation and evolution occurs through random mutations.

Double J

[JimmyDavid]

Originally posted by Double J


I hope this simple model allows you to realize that not all adaptation and evolution occurs through random mutations.

Double J

Well, that's been what i've struggled to say. Isn't it!!??

Evolution through genetic combination sounds more logical. Still, it doesn't explain everything, notice that genetic mixing within a population has more of a tendency to LEVEL and not ADD UP. When 2 giraffes breed, one will have a longer neck than the other; the offspring will lickely have a neck lenght that's between both. You can say that the more a species breeds, the more it searches for a stable form of it's own.
And Don't forget that an asexual creature evolves as well. How do you explain that?

[CamHanna]

Perhaps albinism wasn't a good example as it is not a beneficial trait.

Melinism in Ontario's eastern garter snake is a simple recessive mutation that is quite common in some populations. Presumably a black snake is at an advantage because it can warm up faster and thus reduce it's basking time and increase it's chances of survival. Because it is beneficial the mutation has proliferated.

It's true that hets won't have the same benefit as homos but also, a het is no worse off than the rest of the population. When it breeds to a normal a het produces 50% hets. Certainly not all the hets will survive to adulthood but likely some will and eventually two hets are likely to breed together. If the homo form is successful then it will either produce more hets when bred with a normal or more homos when bred with a homo (or het). This all occurs in wild eastern garter snake populations.

Like Cake pointed out there are patterns of heritability at play as well.

I should also point out that one successfull mutation doesn't make a new species, only a new morph. To make a new species it takes many, many mutations. So many that the new species no longer interbreeds with the old species.

A mutated animal likely won't have trouble finding a mate should it survive to adulthood. Melinistic garter snakes is one example but perhaps corn snakes are a more familier one. A captive albino-motley-anery-lavender will readily breed with a normal. I'm sure that if the two met in the wild (though there aren't many wild a-m-a-l corns) they would be just as likely to breed.

A species is defined as a group of individual that will interbreed. So, once our 'mutant' group no longer breeds with the normal group it is a new species. Speciation, like I said earlier, takes place after many, many, many small mutations.

I should point out, like Double J did, that not all 'mutations' (i've used the word loosely), are as simply as melinism. The giraffe example is a good one where neck length is probably dependent on a number of genetic influences but none-the-less is passed to the offspring.

Cam

[Removed_2815]

Originally posted by JimmyDavid
Well, that's been what i've struggled to say. Isn't it!!??
No, and I think you've missed the point again.
Mutations are the source of all genetic variation. Genetic variation refers to the genetic heterogeneity in a population.

Ryan

[JimmyDavid]

Originally posted by CamHanna

I should also point out that one successfull mutation doesn't make a new species, only a new morph. To make a new species it takes many, many mutations.

Cam

Now there a agree totaly. And that's what makes one think what are the odds that another mutation comes along to continue EXACTLY the work started by the previous.

[JG20]

Wow, that was a great read. All eight pages, so far...

JimmyDavid, you're totally missing it. There's no documented evidence of an individual/organism changing it's genetic compositon or that of it's gonads through physiological, metal, or whatever type of training. If there was, then the whole evolutionary theory would be shot down.

BTW, evolution is both a theory and a fact. It is fact because it is occuring as we speak (err type). Speciation is happening in front of our eyes. However, since we cannot prove the past, evolution is the theory of how we (ie all living things) came to be.

RMBolton, Double J, Cake, CamHanna, etc. have already gone through the points so I won't bother but take their advice, do more reading on the subject. If you can find any evidence of an individual able to change it's genetic makeup, I'm sure, we would al be changing our minds and so would the rest of the scientific community.

Joe

[JimmyDavid]

Can't argue with that!
But i'm a believer that it can happen. Perhaps one day we'll know.

So far, it's know to be possible that a creature undergoes a somatic genetic change through it's life. That means it changes it's own genetics, only can't pass it to it's offspring. Maybe the future will tell us how much that influences a germlike mutation as well (so far, thought to be impossible).

[CamHanna]

Posted by JimmyDavid
So far, it's known to be possible that a creature undergoes a somatic genetic change through it's life.
Are you refering to cancerous mutations or do you have some other evidence?

[JimmyDavid]

Animals that change sex through the course of it's life, for example.

[Removed_2815]

Originally posted by JimmyDavid
That means it changes it's own genetics
Sorry, but no. Mutations in somatic cells are caused by radiation, carcinogenic chemicals, or transcription errors. Someone already mentioned this here when discussing cancerous tumours. The "creature" certainly does not change its own genetics.

Ryan

[JG20]

Originally posted by JimmyDavid
So far, it's know to be possible that a creature undergoes a somatic genetic change through it's life. That means it changes it's own genetics, only can't pass it to it's offspring. Maybe the future will tell us how much that influences a germlike mutation as well (so far, thought to be impossible).

Again, not proven. You're gonna have to provide some sort of literature behind this claim. Could you refer me to a textbook, published article or journal that claims this?

Joe

[JimmyDavid]

Creating an extra gene and changing from male to female is a genetic change.

Here, i found a site on that:
http://www.crystalinks.com/biology2.html

But there are lots of cases involving populations of frogs, fish and certain anphibians.

[Removed_2815]

Originally posted by JimmyDavid
Animals that change sex through the course of it's life, for example.
Again, sorry, but no. This is not a change of genetics.
The foetuses of all vertebrates develop with elementary forms of female and male genitalia, and the potential to develop one or the other. In most vertebrate species, the genetic sex of the organism dictates whether the foetus develops male or female genitalia, while the other gradually diminishes and disappears.

However, in several species, females grow female genitalia normally, while the elementary male genitalia is maintained for later development (potentially). External stimuli cause changes in the female's hormone levels (such as the death of the primary male in certain Cichlids), eliciting the male genitalia to begin maturing.

Ryan

[Removed_2815]

Originally posted by JimmyDavid
Creating an extra gene and changing from male to female is a genetic change.

Here, i found a site on that:
http://www.crystalinks.com/biology2.html

But there are lots of cases involving populations of frogs, fish and certain anphibians.
Absolute garbage once again. Estrogen-like toxins are responsible in your "source." As I have previously explained, this is not a genetic change but merely a response to varying hormones.

Ryan

Edit: if you want to be taken seriously here, citations of peer-reviewed journals are acceptable, not private websites.

[JG20]

Originally posted by RMBolton
Again, sorry, but no. This is not a change of genetics.
The foetuses of all vertebrates develop with elementary forms of female and male genitalia, and the potential to develop one or the other. In most vertebrate species, the genetic sex of the organism dictates whether the foetus develops male or female genitalia, while the other gradually diminishes and disappears.

Ryan

Yes, this is the reason why men have nipples. Jimmy all I found in your site was that the fish are changing in response to pollutants. They're reacting to unnatural levels of "hormones." The same can be said about women bodybuilders who take testosterone supplements and develop male characteristics. There is no change in their genetic makeup and will not affect their children, unless the hormone supplements are causing mutations in their gonads.

Joe

[Removed_2815]

Originally posted by JimmyDavid
And Don't forget that an asexual creature evolves as well. How do you explain that?
It is explained quite clearly in the scientific literature that one of the main ways these asexual organisms evolve is due to random mutations. These apomictic asexual organisms (parthenogenetic, gynogenetic, etc.) evolve much, much slower because there is no genetic mixis.
Asexual bacteria evolve through conjugation. Again, genetic variation is responsible and mutation is the cause of genetic variation.

Ryan

[Double J]

Jimmy..... you you are continuously jumping to erroneous conclusion after erroneous conclusion, and then posting them without thinking hard, or doing further reading.

As I have said about 7, 8, or 9 times...... follow these steps:

1) Take a break from posting in this thread for a few weeks.

2) Go to the nearest library, and check out a biology text, a genetics text, AND perhaps even a primate evolution text or two or three. Primate evolution texts often cover evolutionary concepts rather well. And when I say texts, I mean texts, not some half-baked pseudoscience paperback.

3) Read them!

4) Then come back and begin a discussion.

I suppose this thread has been rather informative to other members, but I fear that some erroneous ideas and selective quotes may become perpetuated and even accepted by other forum members if RMBolton, Cam, myself, and others have expended our energy and would rather not post on the subject further.

Jimmy, I am in no way insinuating any lack of intelligence, rather, a lack of accurate interpretation of information is the culprit here.

I am growing weary of reading and posting in this thread. Though I do enjoy discussing evolution immensely, this continuous refuting of selective quotations and erroneous ideas is becoming rather taxing.

Double J

[JimmyDavid]

Originally posted by JG20
The same can be said about women bodybuilders who take testosterone supplements and develop male characteristics.

Joe

that is another subject. Those women still have their female reproductive system working like they were born with.
I'm talking about creatures that went through a change that altered their own individual identity. RMBolton said it's not considered genetic change, i say call it what you want, it's a dramatic individual change at all levels.
To create a change in somatic cells you only need a vehicle (some microorganisms can do that) to insert a different gene in the nucleous. As that cell reproduces, and so on, they will spead that change.
The theory that those changes could have an impact on germlike cells (even if by a tiny percentage) would explain the molding of species through generations and it would not be random but following a pattern of consistant alteration (that's what is lacking in the mutation theory).

Anyway, i guess it's time to stop this thread. We could be here debating forever, but the truth is scientists have changed opinion before and they will keep on doing that through the years as they get more information.
Let them worry about that!

[Removed_2815]

Originally posted by Double J
I suppose this thread has been rather informative to other members, but I fear that some erroneous ideas and selective quotes may become perpetuated and even accepted by other forum members if RMBolton, Cam, myself, and others have expended our energy and would rather not post on the subject further.

I agree. I grew weary of this thread a long time ago, but I have a hard time allowing such erroneous information to be posted and not be contested. There's already enough crap on the internet, and I don't enjoy having to refute everything JimmyDavid says, but I won't allow misinformation to spread to other members. It doesn't seem right.

Ryan

[CamHanna]

Posted by JimmyDavid
The theory that those changes could have an impact on germlike cells (even if by a tiny percentage) would explain the molding of species through generations and it would not be random but following a pattern of consistent alteration (that's what is lacking in the mutation theory).

The 'molding' pattern of 'consistent alteration' is explained by mutation/heterozygosity. I've been using single genes to explain the concept but in reality each individual is heterozygous for thousands of different genes (because thousands of mutations occured in thousands of previous generations). This is the variation that Double J explained in his giraffe model. Assuming the selective pressures (environment, predation, prey and so on) remain reletively constant the same combinations of genes will be selected for generation after generation and eventually the population will evolve in some benificial way.

[Cake]

Originally posted by Double J
I am growing weary of reading and posting in this thread. Though I do enjoy discussing evolution immensely, this continuous refuting of selective quotations and erroneous ideas is becoming rather taxing.
[/B]
Couldn't have said it better myself.

[lostwithin]

RMBolton, and the others, I am very impressed with your dedication to this post and correcting all of JimmiyDavid nonsense. I grew very tired of it and it seems that no matter what is said he will come up with some bit of information that he doesn't quite understand and try to use it to suite his point.

As for JimmyDavid, Regardless of your beliefs You are wrong, an individual cannot evolve, It has been proven. a population does how this occurs is beyond your ability to understand. Your own arguments are incorrect and you contradicts your self constantly. Every one of your bits of misinformation has been correct and explained by someone more knowledgeable so why not just give everyone a break. Questions and comments from people willing to learn are great your contribution to this conversation is pointless.

Devon

[JimmyDavid]

For ryan:

Heck, i promissed this thread would have an end but i wanted to submit one final thought.
Still on the mutation causing evolution. How do you explain that a mutation goes around the "contained factor"? Most species are territorrial and live all their lives around a certain area. Also many species relate only with members of their hurd or group (even sexually). I could see mutation being responsible for creating a locale, but not an entire species.

[CDN-Cresties]

Is this room 204 Biology???:p

[JG20]

Originally posted by JimmyDavid
that is another subject. Those women still have their female reproductive system working like they were born with.
I'm talking about creatures that went through a change that altered their own individual identity. RMBolton said it's not considered genetic change, i say call it what you want, it's a dramatic individual change at all levels.
To create a change in somatic cells you only need a vehicle (some microorganisms can do that) to insert a different gene in the nucleous. As that cell reproduces, and so on, they will spead that change.
The theory that those changes could have an impact on germlike cells (even if by a tiny percentage) would explain the molding of species through generations and it would not be random but following a pattern of consistant alteration (that's what is lacking in the mutation theory).


Sorry, I have to chime in one last time here. What happens with animals that change sex is a change in gene expression due to environmental stimuli. Vertebrates, as RMBolton stated earlier, form "templates" as fetuses and then develop into males or females after certain conditions are met. In the case of mammals, the presence of testosterone dictates a male. In the case of certain reptiles, incubation dictates sex. In either case, both sexes have the genes to become male or female, no new genes are added. In humans fetuses all start out as females because they are "easier" to make. Again, this is why human males and most other male mammals have nipples. It is not until testosterone is released that the fetus starts growing male parts. With humans, it's irreversible (except for plastic surgery), but with certain fish and amphibians, it's not. It's not so hard to understand especially since these animals have no external appendages (ie penises) to be reabsorbed. When you consider the ability of certain amphibians to regrow lost limbs, it's not so far fetched. AGAIN, these animals have the genes to grow both male and female parts. No new genes are created when changing sexes.

Joe

P.S. My previous example was right on, just not as extreme as the complete sex change in certain fish and amphibians. The process is irreversible in humans.

[Double J]

Originally posted by JimmyDavid
Heck, i promissed this thread would have an end but i wanted to submit one final thought.

Have we not had like 30 of these?

Originally posted by JimmyDavid

Still on the mutation causing evolution. How do you explain that a mutation goes around the "contained factor"? Most species are territorrial and live all their lives around a certain area. )..

Wrong.
Not to mention, territory and range are entirely different!
A territory simply refers to an area in which one animal, or a cohesive group will defend from others of the same species.


Originally posted by JimmyDavid

Also many species relate only with members of their hurd or group (even sexually)..

What exactly are you getting at here?


Originally posted by JimmyDavid

I could see mutation being responsible for creating a locale, but not an entire species.

I think we are all dumber for having read the above quote.
Think about this again really hard Jimmy. Does it not make sense that a locale specific population could be considered part of the speciation process? All they need is time, and some selective pressure.

[JimmyDavid]

[i]Originally posted by Double J




What exactly are you getting at ? [/B]

What i'm getting at is that i agree that life depends on genetic variation. But i believe
mutation is not the only tool to spark that.

What bothers you is that you can't proove that's wrong. You can only proove that so far it's the only way known.


what originated the very first genetic formed creature, before there was a genetic code to mutate from?

[Double J]

Originally posted by JimmyDavid
What i'm getting at is that i agree that life depends on genetic variation. But i believe
mutation is not the only tool to spark that.

What bothers you is that you can't proove that's wrong. You can only proove that so far it's the only way known.


what originated the very first genetic formed creature, before there was a genetic code to mutate from?

Sweet Christ Jimmy!!!!!!!!!!!!!!!!!!!!!!!!

Have you even READ MY POSTS?????????????????????????

I am frankly at a loss for words.

Does this above quote make any sense to anybody else in reference to what my arguements have been?

[Removed_2815]

Originally posted by JimmyDavid
what originated the very first genetic formed creature, before there was a genetic code to mutate from?
Do you realize how complicated the answer to this is? I honestly don't think we could make you understand the answer to this one either. There are solid scientific data to answer this question, but I'm too exhausted with this thread to explain. We can't keep condensing large quantities of information into single posts, it's too much work and you will get more from reading a text on your own.

This really should be the last post in this thread, so here goes:
Evolution acts on genetic variation, more variation equals a better chance for species survival, and mutations are the source of all genetic variation.
You have to accept this. You can't keep coming on here with your unfounded opinions and trying to pass them off on us.
This isn't scientific arrogance. Direct us to some research that suggests mutation is not the source of genetic variation.

If you don't want to believe this, then that's fine, go get a PhD in genetics and prove the whole scientific community wrong. The fact is there are people on here who know the accepted answers to your questions. You keep throwing it in our faces, and honestly, what was once frustration is quickly becoming anger.

Ryan