Macroevolution

[warri0r45]

I'm not going to pretend to know how to answer your question.

 

If you don't know then why did you try to answer it? All that makes your answer is conjecture.

 

 

 

I'm not going to kid myself. My answer was conjecture. It's not as if you have presented conclusive evidence either, but if you think your idea holds water, write a scientific journal on it.

 

 

 

 

So until that little detail is overcome mules support the idea that macro evolution doesn't happen.

 

 

 

 

It is not individuals that evolve but populations. A population evolves by gradual changes in gene frequency until it becomes a distinct species that is no longer capable of interbreeding with similar populations that shared a common ancestor. All of the individuals within the population can mate successfully with each other so there is no problem with "hybrids". There are quite a few examples of different populations of the same species which have trouble interbreeding, in other words the hybrids are not viable. These populations are evolving and may become separate species. It is a common mistake to assume that a new species begins when an individual "mutates" or "evolves" in a single step - this is simply not how evolution works.

 

 

 

That was more or less my line of thinking with my response to him. But, in all fairness, what I posted was conjecture. You summed up what I should have said - populations evolving eliminate the problem of odd chromosome numbers or genetic inconsistancies due to the gradual nature of mutations.

[dutchdreams]

Kindly explain the occurance of Down syndrome in human population out of parents with 'normal' chromosome numbers. Be sure to include both your claims, specifically on the matter of the fertility of Down syndrome females. I'll give you a clue: these females can produce offspring.

 

Alrighty. In Down syndrome there is extra genetic in the 21 chromosome. It usually results in mild to moderate [developmentally delayed] and is a factor in many negative diseases or afflictions to the person that has it. Additionally like mules males are sterile. Females have about a 50% chance of their child having Down syndrome.

 

 

 

Although persons with Down syndrome seldom reproduce, it is necessary to provide them with a healthy understanding and orientation toward sexuality. Pregnancy has been rare, probably as a result of sexual isolation in institutions, but sometimes does occur. About half the infants born of such pregnancies have Down syndrome. Males with trisomy 21 not associated with mosaicism or translation have not been known to reproduce

 

http://en.wikipedia.org/wiki/Down_syndrome

 

 

 

Extra chromosomal material. Your claim was two-fold:

 

 

 

Claim 1: It would have to happen through asexual procreation. This, according to you, would exlude mammals.

 

 

 

Humans can produce extra chromosomal material in their offspring through sexual procreation, as shown in the case of Down syndrome. No need for asexuality exclusively.

 

 

 

Claim 2: If through sexual procreation: a] the parents must have the same set of chromosomes.

 

 

 

Humans can procreate with parents having different sets of chromosomes, with a 50% chance of giving the extra chromosome to their offspring in the case of Down syndrome. The offspring carrying this extra chromosome feature lives long enough to procreate.

 

 

 

b] The chance of two individuals meeting, having the same set of chromosomes, is too small for the extra chromosomal information to be passed onto their offspring.

 

 

 

Not only is it not required for humans to find 'same-set' parents, it actually depends on intermixing with a 'normal-set' father since the Down-syndrome-male is sterile (the sterility is debated by the way). I'd say this presents a big enough chance for the female to find a partner considering there are roughly 3 billion males walking this planet.

 

The 'normal chromosome' population sustains the one with an 'abnormal set': maybe long enough for the males to overcome their infertility ? Extrapolate this to your example of the rats. Is it still unlikely to have never occured in any organism in the course of millions of years ?

[BlueTear]

So until that little detail is overcome mules support the idea that macro evolution doesn't happen.

 

Err, no, 'cause the female mules are fertile, and can mate with both horses and donkey's. Depending on the exact genetic mix and the father, you can get a horse, or a you can get a donkey. Either way, the female remains fertile. The fact that a combination with 63 chromosones has yet to manage to luck out and hit some concept that would become dominant in a population - nor is it ever likely to now that humans fiddle with the mix - is in itself rather irrelevant. There is no theoretical hurdle for a species of mules arising from the cross of two separate species.

 

 

 

Though by now, I've lost track of how that relates to macroevolution. It's an hybridization between two existing species giving rise to a third, possibly with better rates of survival. Not the most common method of macroevolution, nor is it neccesary for macroevolution to arrive at the modern word - which is nicely outlined somewhere in the links Death By Pod posted, though as usual they were not read.

 

 

 

Actually scientists have developed a pretty detailed time line of the order they say animals evolved so you had the problems I described in my above post happening on a broad scale with many animals at once in a restrained time frame. There is just no way...

 

 

 

???

 

 

 

Horses and donkeys can mate. They have different number of chromosomes. And that's one example, of mammalians. There's other examples, with wider genetic differences, and let's not even touch flowers cause that's just painy. Add to that Downs syndrome and the other assortment of various interesting genetic conditions, and we've clearly shown that animals _can_ gain more chromosones than their parents, as well as lose some. This directly refutes this statement by you; "The odds of that are insane since we don't even know if an animal can mutate to a higher chromosome level in the first place.". We do know. As is shown by the example of the mule, we don't even need two mules - which is way it's worth noting that the male is sterile, but the female isn't - a fertile female mule and something else can still manage to pull something of.

 

 

 

Ergo, I'd say it is now relatively safe to say that a changing number of chromosomes is not an evolutionary hurdle - something that is also stated amidst the links posted by Death by Pod, though you have to dig a bit deeper to find it - it can happen, and given time, it will happen.

 

 

 

By the way, the process in which the number of chromosomes is altered is called Robertsonian translocation, and quick explanation can be found here. The important bit would be "A Robertsonian translocation is a type of nonreciprocal translocation in which two nonhomologous acrocentric chromosomes (chromosomes with centromeres near their ends) break at their centromeres, following which the long arms become attached to a single centromere. The short arms also join to form the reciprocal product, which typically contains nonessential genes and usually is lost within a few cell divisions."

 

 

 

Alrighty. In Down syndrome there is extra genetic in the 21 chromosome. It usually results in mild to moderate [developmentally delayed] and is a factor in many negative diseases or afflictions to the person that has it. Additionally like mules males are sterile. Females have about a 50% chance of their child having Down syndrome.

 

 

 

Down sydrome... macro evolution in action?

 

 

 

If the extra copy of chromosome 21 leads to an increase in intelligence, how many generations do you reckon it will take before natural selection has made the extra copy a standard of a what - when compared to the species where the error first occured - is a new species? Either way, clearly the number of chromosomes does not pose a hurdle for macroevolution.

[dutchdreams]

Alrighty. In Down syndrome there is extra genetic in the 21 chromosome. It usually results in mild to moderate [developmentally delayed] and is a factor in many negative diseases or afflictions to the person that has it. Additionally like mules males are sterile. Females have about a 50% chance of their child having Down syndrome.

 

 

 

Down sydrome... macro evolution in action?

 

 

 

If the extra copy of chromosome 21 leads to an increase in intelligence, how many generations do you reckon it will take before natural selection has made the extra copy a standard of a what - when compared to the species where the error first occured - is a new species? Either way, clearly the number of chromosomes does not pose a hurdle for macroevolution.

I agree it's not a barrier, it's why I called Ambassadar on his claims. I didn't say the quoted bit in your original post: it was Ambassadar's. Would you mind changing the quotation title in your post ?

[BlueTear]

Whups, sorry, was a bit sloppy when I removed the bit he quoted from you to avoid quote stacking. Corrected.

[warri0r45]

Here's something interesting; an experiment of Diane Dodd, of Yale University (I'll dictate from 'Biology, Seventh Edition, Australian Verision') -

 

 

 

[dictation] Diane Dodd, of Yale University, divided a fruit-fly population, raising some populations on a starch medium and others on a maltose medium. After many generations, natural selection resulted in divergant evolution: Populations raised on starch digested starch more efficiently, while those raised on maltose digested maltose more efficiently. Dodd then put flies from the same or different populations in mating cages and measured mating frequencies.

 

 

 

When flies from 'starch populations' were mixed with flies from 'maltose populations,' the flies tended to mate with like partners. In the control group, flies taken from different populations that were adapted to the same medium were about as likely to mate with each other as with flies from thier own populations.

 

 

 

Results: (mating frequencies)

 

 

 

Starch population males with starch population females: 22

 

Starch population males with maltose population females: 9

 

Maltose population males with maltose population females: 20

 

Maltose population males with starch population females: 8

 

 

 

The strong preference of starch flies and maltose flies to mate with like-adapted flies, even if they were from different populations, indicates that a reproductive barrier is forming between divergant populations of flies. The barrier is not absolute (some mating between starch flies and maltose flies did occur) but appears to be under way after several generations of divergance resulting from the separation of these allopatric (geographically separated) populations into different environments.[/dictation]

 

 

 

All this from an experiment. The trend, to me, is clearly that more time in allopatric populations, the lesser the likelyhood for interbreeding of different allopatric populations. Speciation in progress?

[warri0r45]

 

 

If you don't know then why did you try to answer it? All that makes your answer is conjecture.

 

 

 

That's the problem, people defending macroevolution are just as ignorant as the people who don't understand it. If you want to answer a question at least take the time to research a correct answer. It's not hard with so many online resources these days.

 

 

 

To be fair, with what I was getting from his post (that for speciation to occur, a male and female would have to have the exact same mutation by chance and find each other to do the deed and spread the gene which would have to alienate those two individuals genetically from the original population) I countered with what I felt I knew well, that speciation rather happens from the schism of a population and the subsequent gene flow from it.

 

 

 

I'm trying to do this right but at the same time I know my knowlege on the theory isn't perfect i.e. that there are some parts which I know much better than others and some parts which I don't know at all.

 

 

 

(sorry for the double post :uhh: )

[Ambassadar]

Whew... ok so I have a lot of responses to my post to respond to... here goes...

 

 

 

 

 

It is not individuals that evolve but populations. A population evolves by gradual changes in gene frequency until it becomes a distinct species that is no longer capable of interbreeding with similar populations that shared a common ancestor. All of the individuals within the population can mate successfully with each other so there is no problem with "hybrids".

 

You are debating mating difficulties within a pre existing species where the different populations have the same number of chromosomes. I was addressing what happened when the first member of a species was created that has a different number of chromosomes than any other animal on Earth.

 

 

 

Galapagos Finches are an example of a species which regularly produce fertile hybrids.

 

Either way it is a finch. Same number of chromosomes so it is pointless to the discussion.

 

 

 

As to your link I am not about to go through some website and try to disprove every single thing. This post was made for people to offer reasons why they have a problem with macro evolution. The burden is on people that believe in macro evolution to defend the specific issues brought up. Not for me to go write a book trying to disprove some website you link to. That being said I will go look at the site since you were nice enough to link it.

 

 

 

 

Claim 1: It would have to happen through asexual procreation. This, according to you, would exlude mammals.

 

Humans can produce extra chromosomal material in their offspring through sexual procreation, as shown in the case of Down syndrome. No need for asexuality exclusively.

 

 

 

Claim 2: If through sexual procreation: a] the parents must have the same set of chromosomes.

 

 

 

Humans can procreate with parents having different sets of chromosomes, with a 50% chance of giving the extra chromosome to their offspring in the case of Down syndrome. The offspring carrying this extra chromosome feature lives long enough to procreate.

 

I was talking about creating a new species that has a higher or lower number of chromosomes. For your point to be valid the males would have to be able to reproduce to create the Down Syndrome species. They can't so it is not a viable species so this is not a valid defense to this particular issue I brought up.

 

 

 

Not only is it not required for humans to find 'same-set' parents, it actually depends on intermixing with a 'normal-set' father since the Down-syndrome-male is sterile (the sterility is debated by the way). I'd say this presents a big enough chance for the female to find a partner considering there are roughly 3 billion males walking this planet.

 

And yet no Down Syndrome species of human...

 

 

 

The 'normal chromosome' population sustains the one with an 'abnormal set': maybe long enough for the males to overcome their infertility ? Extrapolate this to your example of the rats. Is it still unlikely to have never occured in any organism in the course of millions of years ?

 

Science is based off observation. Throwing out an idea like that and saying "given enough time don't you think probably could have happened?" is not scientific. You are basing your beliefs on this off of faith.

 

 

 

The fact that a combination with 63 chromosones has yet to manage to luck out and hit some concept that would become dominant in a population - nor is it ever likely to now that humans fiddle with the mix - is in itself rather irrelevant. There is no theoretical hurdle for a species of mules arising from the cross of two separate species.

 

No theoretical hurdle except the fact it hasn't happened. What is all this "luck out" or "maybe theoretically it will happen" or "is it unlikely given enough time this could happen even though it has never been observed in anything resembling this scenario" talk coming from you guys? Science is about observing the universe around us, creating a theory to explain what we see, and then testing that theory to see if it is true. I feel like everyone is forgetting that last part. Give me some concrete proof on this issue. "Theoretically speaking" or "maybe" doesn't cut it as an acceptable defense.

 

 

 

Add to that Downs syndrome and the other assortment of various interesting genetic conditions, and we've clearly shown that animals _can_ gain more chromosones than their parents

 

Show me a new species that was made from the offspring with different chromosomes. Everything you guys mention has a sterile male.

 

 

 

Ergo, I'd say it is now relatively safe to say that a changing number of chromosomes is not an evolutionary hurdle

 

I would say the inability to have a male that can breed with a female of a species is a significant hurdle. I would like to know what you are smoking to think that this isn't a hurdle. :P

 

 

 

If the extra copy of chromosome 21 leads to an increase in intelligence, how many generations do you reckon it will take before natural selection has made the extra copy a standard of a what - when compared to the species where the error first occured - is a new species?

 

This is more "given enough time" or "theoretically speaking it should work" info from you. Show me proof.

[Rebdragon]

Ambassador, you've got a pretty good point on the chromosomes. I don't know the answer; I'm gunna ask my Bio teacher tomorrow about that one.

[Ambassadar]

Thanks Reb. I will be interested to hear what your teacher says...

[warri0r45]

So ambassadar, your main concern is on the fact that, at some point, there had to be an organism with more chromosomes than any other and therefore it had to have a mate of the same number of chromosomes to be able to mate and produce fertile offspring? I just want to get this clear so I know what to look for.

 

 

 

edit: perhaps this link will help answer some of your concernes.

 

 

 

link

[Death_By_Pod]

 

You are debating mating difficulties within a pre existing species where the different populations have the same number of chromosomes. I was addressing what happened when the first member of a species was created that has a different number of chromosomes than any other animal on Earth.

 

 

 

Either way it is a finch. Same number of chromosomes so it is pointless to the discussion.

 

 

 

So long as it has an even number of chromosomes, it doesn't matter. It's the same way how some hybrids can bear offspring and some can't. You need an even number of chromosomes so that it can evenly divide during meiosis. The problem is the incompatibility between different species isn't the number of chromosomes but other factors such as basal temperatures and the distribution of vital genetic code across chromosomes. In order to get these variables right you need very similar species, which usually means a very close (or exactly the same) number of chromosomes.

 

 

 

If a population is sufficiently small there is no reason why such a change in chromosome number unsustainable. The problem normally is that if a population is large enough, any abnormalities would get bred out before they spread too far.

 

 

 

A method of creating new chromosomes is known polyploidy. Basically chromosomes are duplicated, creating new species. This is most common in plants, but there are also cases in animals (and fungi) as well. Chromosome fusion can also occur, which fuses together two chromosomes to form one; this is the reason why humans have one less pair of chromosomes then other great apes.

 

 

 

 

As to your link I am not about to go through some website and try to disprove every single thing. This post was made for people to offer reasons why they have a problem with macro evolution. The burden is on people that believe in macro evolution to defend the specific issues brought up. Not for me to go write a book trying to disprove some website you link to. That being said I will go look at the site since you were nice enough to link it.

 

What's the point in having to defend macroevolution if any other possible viewpoint contradicts observation. If you have another view, it should at least be consistent with current observations. As far as anyone is aware, theories of creationism fail to be consistent with observation.

 

 

 

 

Show me a new species that was made from the offspring with different chromosomes. Everything you guys mention has a sterile male.

 

Except speciation isn't normally associated with producing hybrids or a change in chromosome count. For example http://en.wikipedia.org/wiki/Polyploidy Straw man for the lose. Can we stop with all this hybrid talk when it has nothing to do with speciation.

[dutchdreams]

 

Claim 1: It would have to happen through asexual procreation. This, according to you, would exlude mammals.

 

Humans can produce extra chromosomal material in their offspring through sexual procreation, as shown in the case of Down syndrome. No need for asexuality exclusively.

 

 

 

Claim 2: If through sexual procreation: a] the parents must have the same set of chromosomes.

 

 

 

Humans can procreate with parents having different sets of chromosomes, with a 50% chance of giving the extra chromosome to their offspring in the case of Down syndrome. The offspring carrying this extra chromosome feature lives long enough to procreate.

 

I was talking about creating a new species that has a higher or lower number of chromosomes. For your point to be valid the males would have to be able to reproduce to create the Down Syndrome species. They can't so it is not a viable species so this is not a valid defense to this particular issue I brought up.

 

 

 

For the species to propagate/form you propose a mechanism, based on what you believe is needed (two same-set indivuals having to find eachother) and extrapolate at will (the chance of two such individuals ever meeting). I present you with a case that contradicts your a-priori assumptions and now you deem my example as invalid. Solid science at work ?

 

 

 

For your point to be valid they would have to have the same chromosome number *and meet, within one generation*. You claim chances are too slim for two mutations meeting up and hence, the mutation gets lost after one generation.

 

I showed you through the occurance of Down syndrome that it's perfectly possible to create chromosomes 'out of nothing' and sustain the mutation in a population without needing same-set parents at all times at a specific time. It presents a whole different time line to what you propose. Your dogma 'it can't happen because two freak mutations have to occur at the same time AND meet within that very same generation' is shown wrong.

 

 

 

Natural selection and (geographical) group-isolation would instigate the further differentation of the two original groups to become seperate species (gene-mutation is a continuous process). Till both genomes have so differentiated through group-isolated mutations that they can't produce viable offspring anymore by intermixing of the two groups, hence have become two seperate species. Darwin made observations on Galapagos to come up with that theory.

 

Looks to me you have a wrong idea of cause and effect within that theory. Let's hear your theory on how species have come about.

 

 

 

Not only is it not required for humans to find 'same-set' parents, it actually depends on intermixing with a 'normal-set' father since the Down-syndrome-male is sterile (the sterility is debated by the way). I'd say this presents a big enough chance for the female to find a partner considering there are roughly 3 billion males walking this planet.

 

And yet no Down Syndrome species of human...

 

 

 

How long has HomoSapiens been around ? Estimates vary from 40,000-200,000 years: that's less than 0.005% of the Earth's age (.....)

 

The observation presented in my quote disputes your dogma that same-set parents are needed to procreate at the very same moment the mutation is formed to sustain that mutation over a prolongued period of time. It presents a whole different probability of two mutated organisms eventually meeting up. Your extrapolation of time required was shown wrong.

 

You allow yourself to assume a timeline on how quickly mutations have to meet before the mutation dies out, yet have a problem with others showing something else based on observables ?

 

 

 

The 'normal chromosome' population sustains the one with an 'abnormal set': maybe long enough for the males to overcome their infertility ? Extrapolate this to your example of the rats. Is it still unlikely to have never occured in any organism in the course of millions of years ?

 

Science is based off observation. Throwing out an idea like that and saying "given enough time don't you think probably could have happened?" is not scientific. You are basing your beliefs on this off of faith.

 

 

 

You throw out unsubstantiated ideas about asexual/sexual procreation and formation of extra chromosomes and about the time scale this should happen. Despite me presenting you with a simple case observed in humans that contradicts your dogmas, you lecture me about science, *cute*.

 

 

 

I show you a case in humans on how additional chromosome material is sustained for centuries within a population and the only ideas you throw out are: 'it cant happen, it doesn't happen because chances are too slim, it's not possible only maybe through asexual procreation'. Who's blind to observations here, you or me ?

 

According to you I can't say: 'given enough time it can happen', but you can say: 'it can't happen because there's not enough time', lol. According to you, you can say: 'it's too unlikely to have happened for me to believe it', but I can't ask you if it seems 'so unlikely still'. Exactly how much faith and personal beliefs did you put into that rats example ?

 

 

 

Summary of your own ideas:

 

 

 

Observation: Additional (aberrant) chromosomes are created in humans through sexual procreation, out of 'normal parents', Down syndrome occurs.

 

Your conclusion: additional chromosome material can only be introduced through asexual procreation. This excludes all mammals. No organism has been known to mutate to higher chromosome count.

 

 

 

Observation: Down syndrome can be sustained and depends on intermixing with a 'normal parent' to sustain the additional chromosome material in the gene-pool of the population, regardless of time.

 

Your conclusion: for an aberrant genome to survive, two organisms with the same genome are required to mate within the life-span of the individuals carrying that same genome, or else that extra chromosome material will be lost. Chances are too slim, so no new species can stem from that.

 

 

 

Where's your science/reasoning in explaining both those observations ?

 

 

 

Since you formulate your ideas contradicting observations I'll call them dogmas rather than hypotheses. Once again, you're very welcome to explain the occurance of Down syndrome with your dogmas as the starting point.

[warri0r45]

Here's something interesting; an experiment of Diane Dodd, of Yale University (I'll dictate from 'Biology, Seventh Edition, Australian Verision') -

 

 

 

[dictation] Diane Dodd, of Yale University, divided a fruit-fly population, raising some populations on a starch medium and others on a maltose medium. After many generations, natural selection resulted in divergant evolution: Populations raised on starch digested starch more efficiently, while those raised on maltose digested maltose more efficiently. Dodd then put flies from the same or different populations in mating cages and measured mating frequencies.

 

 

 

When flies from 'starch populations' were mixed with flies from 'maltose populations,' the flies tended to mate with like partners. In the control group, flies taken from different populations that were adapted to the same medium were about as likely to mate with each other as with flies from thier own populations.

 

 

 

Results: (mating frequencies)

 

 

 

Starch population males with starch population females: 22

 

Starch population males with maltose population females: 9

 

Maltose population males with maltose population females: 20

 

Maltose population males with starch population females: 8

 

 

 

The strong preference of starch flies and maltose flies to mate with like-adapted flies, even if they were from different populations, indicates that a reproductive barrier is forming between divergant populations of flies. The barrier is not absolute (some mating between starch flies and maltose flies did occur) but appears to be under way after several generations of divergance resulting from the separation of these allopatric (geographically separated) populations into different environments.[/dictation]

 

 

 

All this from an experiment. The trend, to me, is clearly that more time in allopatric populations, the lesser the likelyhood for interbreeding of different allopatric populations. Speciation in progress?

 

 

 

I'm keen to hear of any barriers that would prevent this turning into speciation. Aside from this, if there are macroevolution skeptics out there, can you suggest another viable scientific explanation for the origin of species?

 

 

 

People will probably think 'yeah, I can see what you're getting at, atheistic warri0r, you!' Not true. I'm genuinely interested in the truth of the matter, not which theory is correct. Today at uni, I had two lectures on evolution, each of which backed up all previous knowlege I had and expanded upon it a little. As I see it at the moment, evolutionary theory is logical explanation of the natural mechanisms which cause genetic change within populations, which, according to the theory, can form new species.

 

 

 

I am genuinely interested in why some people believe speciation can not happen and what alternative theories they have for the origin of species. Thus far, I'm pleased that it's gone so well and encourage you all to contine in the same vein. Any comments are welcome.

[Meesy]

Microevolution is true.

 

Macroevolution isn't.

 

 

 

It's not that hard.

 

 

 

Anyway, the reason macroevolution can't be true is because some things, such as the human ear, immume system or whatever organ, are too complicated to be created by just adjusting to the surroundings.

 

 

 

Compare it to a bike evolving into a motorbike, I mean it looks the same and all. But to come from a bike to a motorbike it takes a lot of stages which have no function on itself to get to the point where you reach something new that is new, useful or gives you an advantage. Now you get in the sphere of intelligent design, where something has been guiding these evolution into a certain way where species have gained "things" (that being body parts, abilities or whatever) that on itself have no use at that point but are needed for a more advanced mechanism.

[warri0r45]

Microevolution is true.

 

Macroevolution isn't.

 

 

 

It's not that hard.

 

 

 

Anyway, the reason macroevolution can't be true is because some things, such as the human ear, immume system or whatever organ, are too complicated to be created by just adjusting to the surroundings.

 

 

 

Compare it to a bike evolving into a motorbike, I mean it looks the same and all. But to come from a bike to a motorbike it takes a lot of stages which have no function on itself to get to the point where you reach something new that is new, useful or gives you an advantage. Now you get in the sphere of intelligent design, where something has been guiding these evolution into a certain way where species have gained "things" (that being body parts, abilities or whatever) that on itself have no use at that point but are needed for a more advanced mechanism.

 

 

 

What you're explaining dosen't disprove macroevolution, sorry. There are reasonable explanations for the complexity of some biological systems we see today. Your main assumption is that each step to creating a full, functioning system can only mean that the system dosen't work yet and hence won't be selected for. It's not the evolutionary way of thinking. The evolution of something like the eye, for example, has many intermediate stages, may of them you can see in living species of mollusk. All you need for a crude eye is a compound such as retinal (which detects light) in a few cells. Again, what you're suggesting is that evolution works to a plan and has to go through stages of development to get a final product, which isn't true.

 

 

 

link

 

link. There's a section on the evolution of the eye here. Just google search some more, if you like.

[warri0r45]

Hey people, I thought we had a pretty decent dialogue going before in this thread but it seems to have stopped so I'll give it a little nudge. I'm willing to learn out of all of this as well as my knowlege on the theory is by no means an expertise. I've learnt a fair bit on evolution in my time on three different levels yet am still willing to see the flaws in it or the impossibilities of microevolution compounding into macroevolution.

[Death_By_Pod]

It's not going to get any more replies because people who [cabbage] on macro evolution move on to new topics so they don't have to defend their claims.

[warri0r45]

It's not going to get any more replies because people who [cabbage] on macro evolution move on to new topics so they don't have to defend their claims.

 

 

 

Yeah... There's probably some truth in that. I mean, I want to hear thier side of the story, I invite them to explain why and no results so far. They seem so damn sure that it's impossible sometimes I just want to know why and what barriers prevent it.

 

 

 

Gotta keep being optimistic...

[Meesy]

To help you keep your topic alive, because I find it quite interesting even though this is not me area of expertise by far (I study economics ^^;); I'm interested how you think that life started? How did we become from something not-living (a protein) to a living cell. And if you believe in the Big-bang, or whatever you want to call it, how can you live with the fact that the human species is just an "accident" which even had like a, what, 0,00.... % of happening?

 

 

 

Once again, out of pure interest. :)

[Tigra00]

To help you keep your topic alive, because I find it quite interesting even though this is not me area of expertise by far (I study economics ^^;); I'm interested how you think that life started? How did we become from something not-living (a protein) to a living cell. And if you believe in the Big-bang, or whatever you want to call it, how can you live with the fact that the human species is just an "accident" which even had like a, what, 0,00.... % of happening?

 

 

 

Once again, out of pure interest. :)

 

 

 

Lightning. All it takes it electricity to start life up. That's all we are, really. Stop our electric current, and we die. You can also restart that current and we're back!

 

 

 

Ahem, but it's something like that. They believe that the original...stuff...sorta' came together and made up a "cell" and then lightning from the atmosphere struck the water and started life. Some crap like that. I don't understand it all, really. I don't care much anymore. :shock:

[warri0r45]

To help you keep your topic alive, because I find it quite interesting even though this is not me area of expertise by far (I study economics ^^;); I'm interested how you think that life started? How did we become from something not-living (a protein) to a living cell. And if you believe in the Big-bang, or whatever you want to call it, how can you live with the fact that the human species is just an "accident" which even had like a, what, 0,00.... % of happening?

 

 

 

Once again, out of pure interest. :)

 

 

 

Although not much to do with macroevolution, I'll give you a rundown of what I learnt in uni the other day.

 

 

 

Firstly, the big bang. I'm no expert on cosmology or serious physics so I'm no expert here. Perhaps god did this one, I really don't know.

 

 

 

Secondly, stellar evolution and the formation of the earth. Here's where the fundamental particles begin to condense into atoms and simple molecules (to boil it down a lot) and they, in turn, begin to condense into dense masses called stars, which undergo fusion nuclear reactions to make larger atoms, up to about the element of iron. Out of interest, all of the elements heavier than iron are/were formed through supernovas - super high energy dying stars. Out of all the the wierd and wonderful new elements, planets could come from masses of gas that cooled to a point where it bacame solid.

 

 

 

Thirdly, abiogenesis. Life from non life. Compounds thought to have existed at the beginning of earth's history (CH4, NH3, H2, H20, etc) combined with electricity (basically in the form of lightning) can create compounds such as alanine, glutamic acid, (common amino acids found in organisms) other amino acids and complex, oily hydrocarbons. Search for Miller and Urey; they experimented and got these results. After this, these monomers, as they do naturally, became polymers or formed things like polypeptides (protiens) and oily membranes (a crude form of cell membranes found around every cell on the planet). After this protobions formed; very primative resemblances of cells. Then, protobions eventually became real cells with the ability to function and reproduce independantly (these last two are hazy and I didn't add too much detail here).

 

 

 

Fourthly, evolution; what this topic is about (well, essentially it's more about macroevolution, but I don't mind at the moment). Natural selection states that organisms best suited to thier environment and those whose mating frequency is higher are biologically fit and have a greater opportunity than organisms not fit to pass on thier genes. This leads to a population evolving, note that individuals never evolve (although they can gain mutations from thier parent/s, which occur naturally, which is the source of genetic variation [among other things]). Now there is much more detail I could go into with this one, but that's basically the mechanism which allows it to happen in a nutshell.

 

 

 

I'm not lying to you when I say evolution (this fourth point) is a fact. Search for Hardy-Weinburg equilibrium and it might help you understand that statement a bit more. The section of the theory which is still a theory - macroevolution - is what this topic is about. Essentially a whole bunch of microevolution over time through separation of a population (or it can happen within the same population, but that's a bit more complex) and the subsequent natural selection will lead to new species being formed. All tangible evidence in nature suggests this occuring - comparative anatomy, embryology, DNA sequences (we share 98% of our DNA with chimps and about 200 of our 30,000 genes with certain bacteria!) and biochemistry along with the fossil record and the geological time scale (reinforced through radiometric dating) shows this.

 

 

 

Hope this helps you a bit. Note that I didn't exclude god. You can always reconcile your beliefs with science, no matter what they are. Just remember to listen to what scientists say about science and what pastors say aout religion. There is no doubt in the scientific community that evolution happened/is happening.

 

 

 

On a final note, I'd prefer we keep this purely a scientific discussion, forget I even said god or religion if that at all helps.

[warri0r45]

Meh last dig, then I'll let this one die.

 

 

 

http://www.ogtr.gov.au/pdf/ir/biologywheat.pdf

 

 

 

'Triticum Aestivum' or common wheat, is a polyploid which essentially means it has an abnormally high 'n' number or number of chromosome sets which were dirived from 3 diploid plant species as discribed in the above link, section 2, 'taxonomy and genetics'.

 

 

 

The allopolyploidy section of the wikipedia link is quite interesting too. Essentially, meiotic malfunctions that originally cause chromosome set duplications can make sterile offspring which themselves can take on another gamete to even out chromosome set numbers.

 

 

 

E.g. species A with a '2n' of 4 and species B with a '2n' of 6 could, though a meiotic error of species A which prevents the '2n' number havling to 'n', combine to form a hybrid with 7 chromosomes (4 chromosomes from A and 3 from B). Anyone with a basic understanding in genetics would know that an organism must have an even number of chromosomes to form a fertile offspring, so how does this hybrid with 7 become fertile? It hybridises again with the 'n' gamete of species B which gives it a new, even total of '2n' = 10, allowing the new species to produce viable offspring.

 

 

 

Anyway make of that what you will, sorry if I didn't add enough laymans terms in there for those not all that keen on genetics.

 

 

 

As I said, last dig so either pick it apart like crazy, comment, or don't.

[assassin_696]

Nice explanation of the possibilities for abiogenesis, clarified it in my mind when you broke it down like that :)

 

 

 

This is going off evolution a bit, i'm no biologist, I know what I have to know for GCSE and the bit more for rebutting creationists, but you mentioned earlier the possible origins of the Big Bang. This is definitely an interest of mine, obviously no one knows for certain at the moment but here's an interesting article I read which relegates the necessity of a "cause".

 

 

 

http://www.infidels.org/library/modern/ ... aused.html

 

 

 

Make of what you will.

[warri0r45]

Nice explanation of the possibilities for abiogenesis, clarified it in my mind when you broke it down like that :)

 

 

 

This is going off evolution a bit, i'm no biologist, I know what I have to know for GCSE and the bit more for rebutting creationists, but you mentioned earlier the possible origins of the Big Bang. This is definitely an interest of mine, obviously no one knows for certain at the moment but here's an interesting article I read which relegates the necessity of a "cause".

 

 

 

http://www.infidels.org/library/modern/ ... aused.html

 

 

 

Make of what you will.

 

 

 

Sounds interesting, but I'm no expert in physics. :XD:

 

 

 

It sounds compelling though, from what I read.