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RTyp06
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Re: Evolution in action?
« Reply #90 on: March 18, 2007, 04:37:37 pm »

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Sometimes there is not enough time for a suitable mutation to appear. When it comes to the pidgeon for example, it would probably have taking evolution over a very long time and a transformation of the species for them to survive. There can only be so much the species can adapt to within a reasonable amount of time. And species that don't adapt will die out.

Ok, perhaps for that particular example. The evolutionary idea, though, is that animals under environmental distress / selection pressure will fairly quickly evolve in order to survive. The fossil record shows stasis. Most preserved animals seem to come from nowhere, live for X million years, then dissapear from the fossil record altogther. This is the rule rather than the exception.
Quote
Then what about crocs and alligators? Crocs supposidly have been a stable species for millions of years, yet lived just fine through global ice ages that killed off many other species?
Yes, what is the problem with that?

The problem I have with this is that Crocs are considered "living fossils" with little to no morphical change through the millenia and their ancesteral, fossilized remains supposidly date back  ~80 million years. The dinosaurs supposidly died around 60 million years ago due to a massive global extinction event (meteor or comet collision) yet crocs didn't? Then you have the famed ice age animals of wooly mammoths and saber toothed tiger remains that are believed to have lived  from 4.8 million years ago to around 3,500 years ago. Crocs happily lived through this epoch as well? We know from modern crocodial and alligator studies that these animals live in specific temperate climates.. Their eggs in particular produce male or female offspring depending upon the temperature they are incubated at.

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

Quote
Well 53 million years is nothing compared to the age of earth so if anything that proves that with sufficient time and random events unlikely results will be achieved.

The Regis example represents 26 letters of the alphabet and a mere 15 character combination. In living cells, protiens are built from 20 possible amino acids and the "simplest" protien is around 50 amino acids long. (Most folded protiens are hundreds of amino acids in length.) These are then  placed in a specifc order, and folded into a precise 3 dementional shape.

Now, we have found that the amino acid sequence can vary to some degree and some amino acid positions can in fact be substituted. But there are many positions where only one specific amino acid will work in order to get a folded protien. And keep in mind that our diverese cellular structues, such as hair, finger nails, blood, liver tissue, brain  tissue etc. are made from many *different * and many *combinations* of protiens.

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

Quote
http://english.pravda.ru/science/tech/15-03-2005/7885-hiv-0
Quote
Researchers at the University of Liverpool in the U.K. believe that some 10% of Europeans became immune to the human immunodeficiency virus (HIV). They argue that new immunity characteristics were caused  by the mutation of some genes as a result  of the plague epidemics during the Middle Ages. In particular, a Delta-32 mutation affecting a cellular receptor of the gene CCR5 makes the human body protected against the HIV. The above genetic mutation is most frequently found in the residents of Scandinavian countries and Russia.
Beneficial mutation?

Every one of us has a unique immune system. Our immune systems are built with a large amount of jumping genes or mobile genetic elements. This is why I may have allergies where you may not.

Let's say a super flu hit the world and killed 90% of human population leaving 10% to survive and carry on the species. In a sense this is evolution via. natural selection. The flu resistant people didn't evolve to cope with the flu epidemic ,but rather some of the population was already immune, thus not affected. Also every survivor is not a new species of human. So, even though this *may* be a benefical genetic mutation, it says nothing about the morphilogical changes darwinian evolution predicts.
« Last Edit: March 18, 2007, 05:06:00 pm by RTyp06 » Logged
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Re: Evolution in action?
« Reply #91 on: March 18, 2007, 05:59:32 pm »

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You're comparing apples to oranges. If you're trying to use genetic algorithms to achieve a specific goal, you need to use a fitness function that corresponds to what you want. For example, if you want to evolve a sorting program, the fitness of your program is (typically) how close to the right order you get; if you choose something unrelated, there's nothing to favour programs with the desired trait. The biological equivalent would be selective breeding of animals (e.g. dogs) for a specific task (e.g. herding sheep).

The long-term natural evolution scenario could be considered to be (very roughly) equivalent to a genetic algorithm where the fitness function is, essentially, capability to survive and reproduce in whatever environment the organism is in.

The point here, anyway, was to illustrate that a wide range of goals can be met by evolutionary processes, not that genetic algorithms are always equivalent to the evolution of life on Earth.

Good points. My point would be that without some sort of established goal, true random mutation is virtually powerless to achieve anything. According to you, In nature, the fitness function is represented by natural selection. To me, natural selection can only act after function is established and is not absolute. We see survival of the luckiest (wrong place at the wrong time could wipe out a species), survival of the weakest  (a human baby is a good example) and we cannot pinpoint what the "fittest" really is.

Quote
The problem with that counter-argument is that it's not really true. Considering the sheer amount of genetically different individuals of our species alone (with different strengths and weaknesses)...

Some examples please?


Quote
...compared to the large amount of species of bacteria with billions of identical individuals, I'd say that complexity does not limit diversity.

I agree that complexity does not limit diversity, just that *randomly* stumbling upon the diversity we see in nature becomes exponentially more difficult.



Quote
Dembski's reasoning (or at least this particular part) would be a sensible argument against evolution if, for example, bacteria must have flagella to survive (many don't). The argument against Dembski is that life needn't be like we see it; there is a huge amount of possibilities, and the probability of a specific mechanism appearing is irrelevant.

Very true. But consider the fact that flagella did evolve, this would give flagella equipped bacteria a survival advantage right? yet living, unequipped bacteria compete just fine in the same environments?

And if a specific mechanism evolving is irrelevent, why do we not see any of these other countless possibilities manifest?

Let me try to explain in another way.. Chance evolution predicts that elephants and dolphins could have just as easily recieved the equivilant of the human brain and we could have easily remained an ape species indefinately. But isn't it odd that the one species that recieved the human type brain has the nessicary tools to go along with it? Could dolphins or elephants smelt metals, design intricate machines, explore space etc. with a trunk or a pair of flippers instead of hands with opposible thumbs?

Likewise, flagella equipped bacteria have the nessicary sensory organs and tools to control thier flagella in a useful fashion, it's not like you can just throw a flagella on any single celled organism and off you go. Not only does the organism need to grow the flagella, but in specifc sequences and in intricate protien combinations.

When expirimental science discovered how to duplicate wings, eyes and legs in various places on a fruitfly, this is only half the battle. These are useless to the animal unless the muscles and brain connections can utilize them.

All the intricate microcellular machines inside a cell act like a complier of a programming language. Just like a modern programming language the code needs to be fairly specific. You can't just throw random codes in and expect it to compile. At least not in any meaningful way.

Anyway, Dembski may need to work on his Specified Complexity arguments but I still think he has the right idea.
« Last Edit: March 18, 2007, 06:01:42 pm by RTyp06 » Logged
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Re: Evolution in action?
« Reply #92 on: March 19, 2007, 05:32:10 pm »

Good points. My point would be that without some sort of established goal, true random mutation is virtually powerless to achieve anything. According to you, In nature, the fitness function is represented by natural selection. To me, natural selection can only act after function is established and is not absolute.

yes. Function is established by the creature growing up and using what it has. Then natural selection judges whether it was any good. Your problem?
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Re: Evolution in action?
« Reply #93 on: March 19, 2007, 08:17:47 pm »

Quote
Sometimes there is not enough time for a suitable mutation to appear. When it comes to the pidgeon for example, it would probably have taking evolution over a very long time and a transformation of the species for them to survive. There can only be so much the species can adapt to within a reasonable amount of time. And species that don't adapt will die out.

Ok, perhaps for that particular example. The evolutionary idea, though, is that animals under environmental distress / selection pressure will fairly quickly evolve in order to survive. The fossil record shows stasis. Most preserved animals seem to come from nowhere, live for X million years, then dissapear from the fossil record altogther. This is the rule rather than the exception.

Yes quick, but in a "geological" sense, that's much much more than 100 years for example. We have very few fossiles compared to how many individual animals that have lived, and the transitory forms most likely lived for a short time, like mentioned before in the thread (http://en.wikipedia.org/wiki/Punctuated_equilibrium). Also there are fossiles that could be "missing links":
http://en.wikipedia.org/wiki/List_of_transitional_fossils
Just take a look at this for example:
http://en.wikipedia.org/wiki/Ambulocetus

Quote
Then what about crocs and alligators? Crocs supposidly have been a stable species for millions of years, yet lived just fine through global ice ages that killed off many other species?
Yes, what is the problem with that?

The problem I have with this is that Crocs are considered "living fossils" with little to no morphical change through the millenia and their ancesteral, fossilized remains supposidly date back  ~80 million years. The dinosaurs supposidly died around 60 million years ago due to a massive global extinction event (meteor or comet collision) yet crocs didn't? Then you have the famed ice age animals of wooly mammoths and saber toothed tiger remains that are believed to have lived  from 4.8 million years ago to around 3,500 years ago. Crocs happily lived through this epoch as well? We know from modern crocodial and alligator studies that these animals live in specific temperate climates.. Their eggs in particular produce male or female offspring depending upon the temperature they are incubated at.

http://en.wikipedia.org/wiki/Crocodilia
Most likely the crocodiles were not impacted severely enough when the dinosaurs died out and during the ice age they probably lived in unaffected regions too. But really millions of crocodiles may have died during the ice age or when the dinosaurs were extinct, they may just have survived barely.

Quote
Well 53 million years is nothing compared to the age of earth so if anything that proves that with sufficient time and random events unlikely results will be achieved.

The Regis example represents 26 letters of the alphabet and a mere 15 character combination. In living cells, protiens are built from 20 possible amino acids and the "simplest" protien is around 50 amino acids long. (Most folded protiens are hundreds of amino acids in length.) These are then  placed in a specifc order, and folded into a precise 3 dementional shape.

Now, we have found that the amino acid sequence can vary to some degree and some amino acid positions can in fact be substituted. But there are many positions where only one specific amino acid will work in order to get a folded protien. And keep in mind that our diverese cellular structues, such as hair, finger nails, blood, liver tissue, brain  tissue etc. are made from many *different * and many *combinations* of protiens.

http://en.wikipedia.org/wiki/Protien
It's not like these structures have been assembled at random from nothing at all. They've been gradually built up step by step during billions of years.

Quote
http://english.pravda.ru/science/tech/15-03-2005/7885-hiv-0
Quote
Researchers at the University of Liverpool in the U.K. believe that some 10% of Europeans became immune to the human immunodeficiency virus (HIV). They argue that new immunity characteristics were caused  by the mutation of some genes as a result  of the plague epidemics during the Middle Ages. In particular, a Delta-32 mutation affecting a cellular receptor of the gene CCR5 makes the human body protected against the HIV. The above genetic mutation is most frequently found in the residents of Scandinavian countries and Russia.
Beneficial mutation?

Every one of us has a unique immune system. Our immune systems are built with a large amount of jumping genes or mobile genetic elements. This is why I may have allergies where you may not.

Let's say a super flu hit the world and killed 90% of human population leaving 10% to survive and carry on the species. In a sense this is evolution via. natural selection. The flu resistant people didn't evolve to cope with the flu epidemic ,but rather some of the population was already immune, thus not affected. Also every survivor is not a new species of human. So, even though this *may* be a benefical genetic mutation, it says nothing about the morphilogical changes darwinian evolution predicts.
They became immune due to a mutation and natural selection followed. Not all mutations affect the appearance of a species. But what do you think about things like these:
http://en.wikipedia.org/wiki/Rhagoletis_pomonella
Quote
Some evidence, such as the fact that six out of thirteen allozyme loci are different, that hawthorn flies mature later in the season and take longer to mature than apple flies; and that there is little evidence of interbreeding (researchers have documented a 4-6% hybridization rate) suggests that this is occurring. The emergence of the new hawthorn fly is an example of evolution in progress.[http://www.pnas.org/cgi/content/full/94/21/11417]
http://en.wikipedia.org/wiki/Peppered_moth_evolution
   
   
           
   

Let me try to explain in another way.. Chance evolution predicts that elephants and dolphins could have just as easily recieved the equivilant of the human brain and we could have easily remained an ape species indefinately. But isn't it odd that the one species that recieved the human type brain has the nessicary tools to go along with it? Could dolphins or elephants smelt metals, design intricate machines, explore space etc. with a trunk or a pair of flippers instead of hands with opposible thumbs?
No evolution is driven a lot by what specific capabilities a species has. If you can't utilize your superior intelligence then that trait won't be passed on. For example in humans intelligence was a key factor in our survival, likely because of the use of tools and the fact that we had hands that could manipulate thing easily. So the actual fact that we had hands instead of flippers is probably what drove our evolution in the more intelligence direction (This is an interesting field of study in of itself to me. The evolution of intelligence.). Look at this for example:
http://en.wikipedia.org/wiki/Hominid_intelligence
« Last Edit: March 19, 2007, 08:38:07 pm by jucce » Logged
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Re: Evolution in action?
« Reply #94 on: March 21, 2007, 03:29:09 am »

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Yes quick, but in a "geological" sense, that's much much more than 100 years for example.

So an animal cannot evolve in 100 years time?

Quote
We have very few fossiles compared to how many individual animals that have lived, and the transitory forms most likely lived for a short time, like mentioned before in the thread

Why did they die? Not one transitional species linking phyla survives to this day ,even though we have millions of animal species living?

Quote

Palentologists use cladistics to compare bone structures and determine an evolutionary heredity. There are problems with this approach:

Imagine if bulldogs, chiuauas, and great danes were only known from the fossil record. What do you think palentologists would conclude? How about egg laying, duck-billed platypus with poisionus talons? Or what if butterflies and caterpillars were only known in the fossil record?

Also, most often, complete skeletons are not found, leaving much to the imagiantion of the reconstructing palentologist.

Scientists link animals on strange premises. For example from yor wiki link,

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

These are the precursors to dolphins because they share a similar feature in the ear?

(And notice how some of the links remain blank and many other links have wikipedia quality warnings to boot)

And I count a whopping 47 transitional species listed on that wiki page. Darwin himself expected to find countless millions of animals to fill in the gaps in the years ahead of him.

Quote
Most likely the crocodiles were not impacted severely enough when the dinosaurs died out and during the ice age they probably lived in unaffected regions too. But really millions of crocodiles may have died during the ice age or when the dinosaurs were extinct, they may just have survived barely.

Except that "most likely" isn't a convincing scientific piece of evidence and amounts to nothing more than a "just-so" story designed to explain evolution.

Quote
It's not like these structures have been assembled at random from nothing at all. They've been gradually built up step by step during billions of years.

But how exactly do these structures get built step by step? Complex organs for instance need to have everything pretty much working all at once. What good is a muscle without a blood supply, bones to move and control wiring? And what good is blood without a transport system, a pump and lungs (or gills) to supply oxygen? Bones would be useless without all of the above. etc.


Quote
They became immune due to a mutation and natural selection followed. Not all mutations affect the appearance of a species. But what do you think about things like these:
http://en.wikipedia.org/wiki/Rhagoletis_pomonella

Some evidence, such as the fact that six out of thirteen allozyme loci are different, that hawthorn flies mature later in the season and take longer to mature than apple flies; and that there is little evidence of interbreeding (researchers have documented a 4-6% hybridization rate) suggests that this is occurring. The emergence of the new hawthorn fly is an example of evolution in progress.[http://www.pnas.org/cgi/content/full/94/21/11417]
http://en.wikipedia.org/wiki/Peppered_moth_evolution

The evolution in these links isn't outside the realm of microevolution (changes due to breeding alone). I'm not disputing microevolution. The problem is that microevolution has limits and can only change an existing species so far. This has been proven through artifical animal breeding.
   
Quote
No evolution is driven a lot by what specific capabilities a species has. If you can't utilize your superior intelligence then that trait won't be passed on. For example in humans intelligence was a key factor in our survival, likely because of the use of tools and the fact that we had hands that could manipulate thing easily. So the actual fact that we had hands instead of flippers is probably what drove our evolution in the more intelligence direction (This is an interesting field of study in of itself to me. The evolution of intelligence.). Look at this for example:
http://en.wikipedia.org/wiki/Hominid_intelligence

From your link:

Around 10 million years ago the earth's climate entered a cooler and drier phase, which led eventually to the ice ages. One consequence of this was that the north African tropical forest began to retreat, being replaced first by open grasslands and eventually by desert (the modern Sahara). This forced tree-dwelling animals to adapt to their new environment or die out. As their environment changed from continuous forest to patches of forest separated by expanses of grassland, some primates adapted to a partly or fully ground-dwelling life. Here they were exposed to predators, such as the big cats, from whom they had previously been safe.

Man I'd like to take a ride in this guy's time machine. We just don't know what happend for sure and to suggest otherwise is just plain arrogant to me.

« Last Edit: March 21, 2007, 03:35:37 am by RTyp06 » Logged
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Re: Evolution in action?
« Reply #95 on: March 21, 2007, 09:51:07 am »

Quote
Yes quick, but in a "geological" sense, that's much much more than 100 years for example.

So an animal cannot evolve in 100 years time?
Sure it can. I was just thinking about the pidgeon and that 100 years is not enough to evolve when your species is being systematically hunted like that. Like I said, drastic change would have been needed for it to survive.

Quote
We have very few fossiles compared to how many individual animals that have lived, and the transitory forms most likely lived for a short time, like mentioned before in the thread

Why did they die? Not one transitional species linking phyla survives to this day ,even though we have millions of animal species living?
Sure millions of species are alive today but many many more are extinct. I'm not sure what you would accept as a "missing link". Classifying animals into different species is something we humans do in retrospect, if we had every individual from the earliest horse until today I don't think we'd see that clearly delimited species, the change is more gradual.


Quote

Palentologists use cladistics to compare bone structures and determine an evolutionary heredity. There are problems with this approach:

Imagine if bulldogs, chiuauas, and great danes were only known from the fossil record. What do you think palentologists would conclude? How about egg laying, duck-billed platypus with poisionus talons? Or what if butterflies and caterpillars were only known in the fossil record?

Also, most often, complete skeletons are not found, leaving much to the imagiantion of the reconstructing palentologist.

Scientists link animals on strange premises. For example from yor wiki link,

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

These are the precursors to dolphins because they share a similar feature in the ear?
Well if only the cetacean share that trait then it's very likely that the animal is an cetacean.


(And notice how some of the links remain blank and many other links have wikipedia quality warnings to boot)

And I count a whopping 47 transitional species listed on that wiki page. Darwin himself expected to find countless millions of animals to fill in the gaps in the years ahead of him.

Yes but only have very very few animals preserved. It takes very special circumstances for fossils to form.

Can you really disregard all those transitional fossils?
These ones are also kind of interesting.
http://en.wikipedia.org/wiki/Archaeopteryx
http://en.wikipedia.org/wiki/Tiktaalik_roseae

Quote
Most likely the crocodiles were not impacted severely enough when the dinosaurs died out and during the ice age they probably lived in unaffected regions too. But really millions of crocodiles may have died during the ice age or when the dinosaurs were extinct, they may just have survived barely.

Except that "most likely" isn't a convincing scientific piece of evidence and amounts to nothing more than a "just-so" story designed to explain evolution.
I'm not a scientist. But I really don't see why crocodiles couldn't have survived the ice-age, it's not like the entire earth was covered with ice and millions of other species survived it. The same goes for whatever killed the dinosaurs. How did they survive according to you?

Quote
It's not like these structures have been assembled at random from nothing at all. They've been gradually built up step by step during billions of years.

But how exactly do these structures get built step by step? Complex organs for instance need to have everything pretty much working all at once. What good is a muscle without a blood supply, bones to move and control wiring? And what good is blood without a transport system, a pump and lungs (or gills) to supply oxygen? Bones would be useless without all of the above. etc.

Well it's not like you just get a complete eye right away. It's gradual:
* photosensitive cell
* aggregates of pigment cells without a nerve
* an optic nerve surrounded by pigment cells and covered by translucent skin
* pigment cells forming a small depression
* pigment cells forming a deeper depression
* the skin over the depression taking a lens shape
* muscles allowing the lens to adjust

And when it comes to organs, like I said, the development is gradual. And an organ may even change function at some point.

Quote
They became immune due to a mutation and natural selection followed. Not all mutations affect the appearance of a species. But what do you think about things like these:
http://en.wikipedia.org/wiki/Rhagoletis_pomonella

Some evidence, such as the fact that six out of thirteen allozyme loci are different, that hawthorn flies mature later in the season and take longer to mature than apple flies; and that there is little evidence of interbreeding (researchers have documented a 4-6% hybridization rate) suggests that this is occurring. The emergence of the new hawthorn fly is an example of evolution in progress.[http://www.pnas.org/cgi/content/full/94/21/11417]
http://en.wikipedia.org/wiki/Peppered_moth_evolution

The evolution in these links isn't outside the realm of microevolution (changes due to breeding alone). I'm not disputing microevolution. The problem is that microevolution has limits and can only change an existing species so far. This has been proven through artifical animal breeding.

Well that's one change, give it a million years and you'll see a similar constant stream of change. Microevoulution isn't a completely separate concept from evolution. Also the HIV-resistance was because of a genetic mutation. And it says that the Rhagoletis pomonella looks like it's becoming a separate species, so that's quite alot of change.
   
And what about this?
http://en.wikipedia.org/wiki/Nylonase
Scientists were able to induce another species of bacteria, Pseudomonas, to evolve the capability to break down the same nylon byproducts in a laboratory by forcing them to live in an environment with no other source of nutrients.

Quote
No evolution is driven a lot by what specific capabilities a species has. If you can't utilize your superior intelligence then that trait won't be passed on. For example in humans intelligence was a key factor in our survival, likely because of the use of tools and the fact that we had hands that could manipulate thing easily. So the actual fact that we had hands instead of flippers is probably what drove our evolution in the more intelligence direction (This is an interesting field of study in of itself to me. The evolution of intelligence.). Look at this for example:
http://en.wikipedia.org/wiki/Hominid_intelligence

From your link:

Around 10 million years ago the earth's climate entered a cooler and drier phase, which led eventually to the ice ages. One consequence of this was that the north African tropical forest began to retreat, being replaced first by open grasslands and eventually by desert (the modern Sahara). This forced tree-dwelling animals to adapt to their new environment or die out. As their environment changed from continuous forest to patches of forest separated by expanses of grassland, some primates adapted to a partly or fully ground-dwelling life. Here they were exposed to predators, such as the big cats, from whom they had previously been safe.

Man I'd like to take a ride in this guy's time machine. We just don't know what happend for sure and to suggest otherwise is just plain arrogant to me.


It's not arrogant to believe that we can draw conclusions about the past from what we know now. Geological data, fossils and so one can give us an understanding about what is likely to have occured.
« Last Edit: March 21, 2007, 07:29:43 pm by jucce » Logged
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Re: Evolution in action?
« Reply #96 on: March 21, 2007, 04:10:21 pm »

Except that "most likely" isn't a convincing scientific piece of evidence and amounts to nothing more than a "just-so" story designed to explain evolution.

Quote
Man I'd like to take a ride in this guy's time machine. We just don't know what happend for sure and to suggest otherwise is just plain arrogant to me.

While I've resisted feeding the troll for some while now, I couldn't resist pointing out this particularly nasty set of quotes that popped up in the span of a single post.

GET OVER YOURSELF. Nobody knows what happened for sure, nobody knows 100% of the intricacies of the process. Why do you feel the need to write everyone off just because they're offering reasonable guesses? What they have to say carries a hell of a lot more merit than "God / aliens / some random unknown, invisible, all-powerful, and mysterious designer / a wizard did it."

Of course, this will do nothing to stymie the flow of circumstantial evidence, circular reasoning, and arrogant dismissals that have been freely flowing from you since minute one, but I really needed to get this off my chest. Dont worry, I won't interrupt again.

To everyone else: Sorry for the outburst. If you're into troll-baiting, please feel free to carry on.
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Re: Evolution in action?
« Reply #97 on: March 22, 2007, 12:32:44 am »

"What they have to say carries a hell of a lot more merit than "God / aliens / some random unknown, invisible, all-powerful, and mysterious designer / a wizard did it."

Nice straw man.

Hug?
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Re: Evolution in action?
« Reply #98 on: March 22, 2007, 01:54:39 am »



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We have very few fossiles compared to how many individual animals that have lived, and the transitory forms most likely lived for a short time, like mentioned before in the thread

Why did the transitory animals "...most likely lived for a short time..." exactly? Is your reason for "most likely" because of the fact that we are not finding them in the fossil bearing strata? This seems like circular reasoning to me.

Quote
Sure millions of species are alive today but many many more are extinct. I'm not sure what you would accept as a "missing link". Classifying animals into different species is something we humans do in retrospect, if we had every individual from the earliest horse until today I don't think we'd see that clearly delimited species, the change is more gradual.

I do consider Archeopteryx a very plausible missing link. I just can't help wonder why we have so few examples of this calibur.

http://en.wikipedia.org/wiki/Archeopteryx
Quote
Quote
These are the precursors to dolphins because they share a similar feature in the ear?
Well if only the cetacean share that trait then it's very likely that the animal is an cetacean.

It's kinda weak to me.. Too bad the links to "ectotympanic bone " and "auditory bulla" don't have articles yet.



Quote
Can you really disregard all those transitional fossils?
These ones are also kind of interesting.
http://en.wikipedia.org/wiki/Archaeopteryx
http://en.wikipedia.org/wiki/Tiktaalik_roseae

The Tiktaalik is interesting but shouldn't we remember the lessons of the Coelacanth?
http://en.wikipedia.org/wiki/Coelacanth

This fish wast hyped as one of the de facto icons of evolution. We thought it went extinct for 80 million years ago then it turned up living off the coast of Africa. Once we studied the living examples with very little morpic changes over eons of time, we found out it wasn't the land walking proto vertibrate we once thought. No this wasn't a walking fish that represented the move from the ocean to dry land by vertibrates. We have no reason to suspect that the ancient Coelacanth is anything more than it really is, an oily, boney fish with some unique features.

Quote
I'm not a scientist. But I really don't see why crocodiles couldn't have survived the ice-age, it's not like the entire earth was covered with ice and millions of other species survived it. The same goes for whatever killed the dinosaurs. How did they survive according to you?

I'm not a scientist either and you are right, they could have survived, and that might indeed be the case. I just think that the Crocs represent what we see in the fossil record, stasis. We see species living virtually unchanged for millions upon millions of years. Multicellular life was thought to only have arisen 550 to 600 million years ago and yet this amount of time is quickly gobbled up with many, many examples of stasis.


Quote
Well it's not like you just get a complete eye right away. It's gradual:
* photosensitive cell
* aggregates of pigment cells without a nerve
* an optic nerve surrounded by pigment cells and covered by translucent skin
* pigment cells forming a small depression
* pigment cells forming a deeper depression
* the skin over the depression taking a lens shape
* muscles allowing the lens to adjust

Yes and this is the same story Darwin presented in his classic writing "On Origin of Species." But what does it take to get a photosensitive cell?

Let us return to the question, how do we see? Although to Darwin the primary event of vision was a black box, through the efforts of many biochemists an answer to the question of sight is at hand. 4 When light strikes the retina a photon is absorbed by an organic molecule called 11-cis-retinal, causing it to rearrange within picoseconds to trans-retinal. The change in shape of retinal forces a corresponding change in shape of the protein, rhodopsin, to which it is tightly bound. As a consequence of the protein's metamorphosis, the behavior of the protein changes in a very specific way. The altered protein can now interact with another protein called transducin. Before associating with rhodopsin, transducin is tightly bound to a small organic molecule called GDP, but when it binds to rhodopsin the GDP dissociates itself from transducin and a molecule called GTP, which is closely related to, but critically different from, GDP, binds to transducin.

The exchange of GTP for GDP in the transducinrhodopsin complex alters its behavior. GTP-transducinrhodopsin binds to a protein called phosphodiesterase, located in the inner membrane of the cell. When bound by rhodopsin and its entourage, the phosphodiesterase acquires the ability to chemically cleave a molecule called cGMP. Initially there are a lot of cGMP molecules in the cell, but the action of the phosphodiesterase lowers the concentration of cGMP. Activating the phosphodiesterase can be likened to pulling the plug in a bathtub, lowering the level of water.

A second membrane protein which binds cGMP, called an ion channel, can be thought of as a special gateway regulating the number of sodium ions in the cell. The ion channel normally allows sodium ions to flow into the cell, while a separate protein actively pumps them out again. The dual action of the ion channel and pump proteins keeps the level of sodium ions in the cell within a narrow range. When the concentration of cGMP is reduced from its normal value through cleavage by the phosphodiesterase, many channels close, resulting in a reduced cellular concentration of positively charged sodium ions. This causes an imbalance of charges across the cell membrane which, finally, causes a current to be transmitted down the optic nerve to the brain: the result, when interpreted by the brain, is vision.


Quote
And when it comes to organs, like I said, the development is gradual. And an organ may even change function at some point.

This would be so much more plausible with some real, empircal science.


Quote
Well that's one change, give it a million years and you'll see a similar constant stream of change.

But that's the problem bro, animals show abrupt arrival and millions of years of stasis in the fossil record, not a steady, constant stream of intermediates of which Darwin predicted.

Quote
Microevoulution isn't a completely separate concept from evolution. Also the HIV-resistance was because of a genetic mutation. And it says that the Rhagoletis pomonella looks like it's becoming a separate species, so that's quite alot of change.

Of course it's not, in fact Evolution needs breeding changes. Darwin's microevolution of finch beaks is a coner stone to his theory.The problem is that no matter how much we breed animals they don't change in unexpected ways. Although we can achieve some very interesting breeds, it only goes so far. So big, so small.
   
Quote
And what about this?
http://en.wikipedia.org/wiki/Nylonase
Scientists were able to induce another species of bacteria, Pseudomonas, to evolve the capability to break down the same nylon byproducts in a laboratory by forcing them to live in an environment with no other source of nutrients.

This is interesting and I have read a bit about this particular example previously. Seems this could be reproduced in a lab.

Quote
No evolution is driven a lot by what specific capabilities a species has. If you can't utilize your superior intelligence then that trait won't be passed on. For example in humans intelligence was a key factor in our survival, likely because of the use of tools and the fact that we had hands that could manipulate thing easily.

This looks a little "just-so" to me. Interesting idea, but I'd feel much more comfortable with such a scenario with some hard, empirical science.

Quote
It's not arrogant to believe that we can draw conclusions about the past from what we know now. Geological data, fossils and so one can give us an understanding about what is likely to have occured.

Agreed 100%, but when we start going lightyears beyond the scientific data and completely speculate around a single prevailing idea (to the exclusion of any other possible competeing explanations) it's a bit arrogant. At least to me.
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Re: Evolution in action?
« Reply #99 on: March 22, 2007, 06:08:06 am »



Quote
We have very few fossiles compared to how many individual animals that have lived, and the transitory forms most likely lived for a short time, like mentioned before in the thread

Why did the transitory animals "...most likely lived for a short time..." exactly? Is your reason for "most likely" because of the fact that we are not finding them in the fossil bearing strata? This seems like circular reasoning to me.


I was basing that claim on this:
http://en.wikipedia.org/wiki/Punctuated_equilibrium
Which says that evolution happens quickly, in leaps, between periods of relative staticity.


Quote
Sure millions of species are alive today but many many more are extinct. I'm not sure what you would accept as a "missing link". Classifying animals into different species is something we humans do in retrospect, if we had every individual from the earliest horse until today I don't think we'd see that clearly delimited species, the change is more gradual.

I do consider Archeopteryx a very plausible missing link. I just can't help wonder why we have so few examples of this calibur.

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

Well fossils do take some special circumstances to form and who knows how many fossils are left out there. But what's interesting is that we're constantly finding new fossils that appear to be "missing links". I just did a search on Google news quickly:

March 22 2007:
http://www.theage.com.au/news/national/cave-may-hold-missing-link/2007/03/21/1174153159560.html
Quote
Cave may hold missing link
"It represents a kind of stepping stone between very primitive insects and praying mantids," he said. "Or it might be a completely new kind of insect."

March 14 2007:
http://www.pittsburghlive.com/x/pittsburghtrib/news/breaking/s_497722.html
Quote
A fossil of a newly-discovered, chipmunk-sized mammal that roamed the world with the dinosaurs 125 million years ago provides a missing link in the evolution of the middle ear, according to a researcher at the Carnegie Museum of Natural History.

January 25 2007:
http://www.sciencemag.org/cgi/content/abstract/sci;315/5816/1282
Quote
A Missing Link in Membrane Protein Evolution
How do integral membrane proteins evolve in size and complexity? Using the small multidrug-resistance protein EmrE from Escherichia coli as a model, we experimentally demonstrated that the evolution of membrane proteins composed of two homologous but oppositely oriented domains can occur in a small number of steps[...]

March 2 2007::
http://www.associatedcontent.com/article/166059/fossil_find_may_be_one_of_oldest_ever.html
Quote
It could be a "missing link" to the evolution of cuttlefish, squids, and octopus.

Quote
Quote
These are the precursors to dolphins because they share a similar feature in the ear?
Well if only the cetacean share that trait then it's very likely that the animal is an cetacean.

It's kinda weak to me.. Too bad the links to "ectotympanic bone " and "auditory bulla" don't have articles yet.

If educated people working in that field sees a specific feature that only exists within a certain group then I'd say the animal also belongs to that group. From what I understand they've also done genetic testing. It seems it evolved from some sort of hippopotamus and evolved to the (air-breathing) dolphin. The Ambulocetus natans is also from the same suborder.

http://en.wikipedia.org/wiki/Evolution_of_cetaceans#Pakicetids:_the_earliest_cetaceans.3F
Quote
The shape of the ear region in Pakicetus is highly unusual and only resembles the skulls of whales. The feature is diagnostic for cetaceans and is found in no other species.
According to Thewissen, the teeth of Pakicetus also resemble the teeth of fossil whales, which is another link to more modern whales.[3]


Quote
Can you really disregard all those transitional fossils?
These ones are also kind of interesting.
http://en.wikipedia.org/wiki/Archaeopteryx
http://en.wikipedia.org/wiki/Tiktaalik_roseae

The Tiktaalik is interesting but shouldn't we remember the lessons of the Coelacanth?
http://en.wikipedia.org/wiki/Coelacanth

This fish wast hyped as one of the de facto icons of evolution. We thought it went extinct for 80 million years ago then it turned up living off the coast of Africa. Once we studied the living examples with very little morpic changes over eons of time, we found out it wasn't the land walking proto vertibrate we once thought. No this wasn't a walking fish that represented the move from the ocean to dry land by vertibrates. We have no reason to suspect that the ancient Coelacanth is anything more than it really is, an oily, boney fish with some unique features.

That's true, it may not be a proper missing link. But there are 46 others on that list and like I said, it seems like we just keep finding new ones. And also the Archaeopteryx which you agreed is a very plausible missing link.

Quote
I'm not a scientist. But I really don't see why crocodiles couldn't have survived the ice-age, it's not like the entire earth was covered with ice and millions of other species survived it. The same goes for whatever killed the dinosaurs. How did they survive according to you?

I'm not a scientist either and you are right, they could have survived, and that might indeed be the case. I just think that the Crocs represent what we see in the fossil record, stasis. We see species living virtually unchanged for millions upon millions of years. Multicellular life was thought to only have arisen 550 to 600 million years ago and yet this amount of time is quickly gobbled up with many, many examples of stasis.

Yes but that theory "punctuated equilibrium" seems to coroborate that. There is much stasis and then quick bursts of evolution, kind of "the last drop". When it happens it happens alot in a short time, like a dam breaking. Also if one species evolves a specific benefit it may cause a sort of "arms race" because the pressure on other species will increase rapidly. So evolution may also fuel itself.


Quote
Well it's not like you just get a complete eye right away. It's gradual:
* photosensitive cell
* aggregates of pigment cells without a nerve
* an optic nerve surrounded by pigment cells and covered by translucent skin
* pigment cells forming a small depression
* pigment cells forming a deeper depression
* the skin over the depression taking a lens shape
* muscles allowing the lens to adjust

Yes and this is the same story Darwin presented in his classic writing "On Origin of Species." But what does it take to get a photosensitive cell?

Let us return to the question, how do we see? Although to Darwin the primary event of vision was a black box, through the efforts of many biochemists an answer to the question of sight is at hand. 4 When light strikes the retina a photon is absorbed by an organic molecule called 11-cis-retinal, causing it to rearrange within picoseconds to trans-retinal. The change in shape of retinal forces a corresponding change in shape of the protein, rhodopsin, to which it is tightly bound. As a consequence of the protein's metamorphosis, the behavior of the protein changes in a very specific way. The altered protein can now interact with another protein called transducin. Before associating with rhodopsin, transducin is tightly bound to a small organic molecule called GDP, but when it binds to rhodopsin the GDP dissociates itself from transducin and a molecule called GTP, which is closely related to, but critically different from, GDP, binds to transducin.

The exchange of GTP for GDP in the transducinrhodopsin complex alters its behavior. GTP-transducinrhodopsin binds to a protein called phosphodiesterase, located in the inner membrane of the cell. When bound by rhodopsin and its entourage, the phosphodiesterase acquires the ability to chemically cleave a molecule called cGMP. Initially there are a lot of cGMP molecules in the cell, but the action of the phosphodiesterase lowers the concentration of cGMP. Activating the phosphodiesterase can be likened to pulling the plug in a bathtub, lowering the level of water.

A second membrane protein which binds cGMP, called an ion channel, can be thought of as a special gateway regulating the number of sodium ions in the cell. The ion channel normally allows sodium ions to flow into the cell, while a separate protein actively pumps them out again. The dual action of the ion channel and pump proteins keeps the level of sodium ions in the cell within a narrow range. When the concentration of cGMP is reduced from its normal value through cleavage by the phosphodiesterase, many channels close, resulting in a reduced cellular concentration of positively charged sodium ions. This causes an imbalance of charges across the cell membrane which, finally, causes a current to be transmitted down the optic nerve to the brain: the result, when interpreted by the brain, is vision.


I don't know how complex an "eye" that refers to, but here's another explanation:
http://en.wikipedia.org/wiki/Photoreceptor_cell
Quote
The photoreceptor signals its absorption of photons through a release of the neurotransmitter glutamate to bipolar cells at its axon terminal. Since the photoreceptor is depolarized in the dark, a high amount of glutamate is being released to bipolar cells in the dark. Absorption of a photon will hyperpolarize the photoreceptor and therefore result in the release of less glutamate at the postsynaptic terminal to the bipolar cell.
I don't know how primitive a cell could be to only be able to detect light. But photons do impact and affect cells creating some kind of reaction.

Also photosynthesis is strongly connected to light and light sensitivity. Just think about algae and some bacteria.

I found some links when Googling around:
http://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html
http://www.hopkinsmedicine.org/Press_releases/2006/04_14_06.html
http://www.newscientist.com/channel/life/evolution/mg18624995.700
http://en.wikipedia.org/wiki/Ophiocoma_wendtii
http://adsabs.harvard.edu/abs/1994RSPSB.256...53N

Quote
And when it comes to organs, like I said, the development is gradual. And an organ may even change function at some point.

This would be so much more plausible with some real, empircal science.

http://www.livescience.com/animalworld/top10_vestigial_organs.html
http://www.sciencedaily.com/releases/2003/05/030508075843.htm
http://www7.nationalgeographic.com/ngm/0611/feature4/
http://jeb.biologists.org/cgi/content/abstract/35/1/156
http://www.naturalhistorymag.com/master.html?http://www.naturalhistorymag.com/features/0400_feature1.html
http://icb.oxfordjournals.org/cgi/content/abstract/34/2/289

And I'm sure there's much more. But the idea is like with the eye, gradual evolution.

Quote
Well that's one change, give it a million years and you'll see a similar constant stream of change.

But that's the problem bro, animals show abrupt arrival and millions of years of stasis in the fossil record, not a steady, constant stream of intermediates of which Darwin predicted.


Again theories like punctuated equilibrium agree with that. And fossil formation is a rare occurence.

Quote
Microevoulution isn't a completely separate concept from evolution. Also the HIV-resistance was because of a genetic mutation. And it says that the Rhagoletis pomonella looks like it's becoming a separate species, so that's quite alot of change.

Of course it's not, in fact Evolution needs breeding changes. Darwin's microevolution of finch beaks is a coner stone to his theory.The problem is that no matter how much we breed animals they don't change in unexpected ways. Although we can achieve some very interesting breeds, it only goes so far. So big, so small.

Well they claim that Rhagoletis pomonella is becoming a separate species. Then there's the Nylonase. And what about the pig or the dog? So we can certainly get new species. There probably are problems with breeding a dolphin to the size of a blue whale for example, the physiology of the animal may not be compatible with such a big size.

http://www.sciencedaily.com/releases/2006/02/060206232450.htm
http://www.berkeley.edu/news/media/releases/2005/10/27_greeneyed.shtml
http://english.people.com.cn/english/200010/12/eng20001012_52433.html


Quote
And what about this?
http://en.wikipedia.org/wiki/Nylonase
Scientists were able to induce another species of bacteria, Pseudomonas, to evolve the capability to break down the same nylon byproducts in a laboratory by forcing them to live in an environment with no other source of nutrients.

This is interesting and I have read a bit about this particular example previously. Seems this could be reproduced in a lab.


Yes, seems like proper evolution in action.


Quote
No evolution is driven a lot by what specific capabilities a species has. If you can't utilize your superior intelligence then that trait won't be passed on. For example in humans intelligence was a key factor in our survival, likely because of the use of tools and the fact that we had hands that could manipulate thing easily.

This looks a little "just-so" to me. Interesting idea, but I'd feel much more comfortable with such a scenario with some hard, empirical science.

There is science behind this.
http://www.utexas.edu/courses/wilson/ant304/projects/projects97/weimanp/fossils.html
Quote
Whatever the cause of bipedality, it eventually led to the development of higher intelligence. Darwin's theory is that with the freed up hands that bipedality allows, hominids would be able to use tools, and the use of tools led to the development of greater intelligence.
http://history.nasa.gov/SP-419/s2.2.htm
http://en.wikipedia.org/wiki/Evolutionary_psychology
http://ajp.psychiatryonline.org/cgi/content/full/163/9/1652
http://www.cerebromente.org.br/n13/mente/evolution/evolution05_i.html
http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=000C1E5D-B9BA-1422-B9BA83414B7F0103

Quote
It's not arrogant to believe that we can draw conclusions about the past from what we know now. Geological data, fossils and so one can give us an understanding about what is likely to have occured.

Agreed 100%, but when we start going lightyears beyond the scientific data and completely speculate around a single prevailing idea (to the exclusion of any other possible competeing explanations) it's a bit arrogant. At least to me.
I don't think he does that, he extrapolates from what we know and "paints a picture" of how it could have looked.


I found most of the links on google and unfortunately sometimes you find results that are references to books or sites you have to pay to access so I'm sure there are better sources out there.
« Last Edit: March 22, 2007, 06:30:27 am by jucce » Logged
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Re: Evolution in action?
« Reply #100 on: March 23, 2007, 01:53:16 am »

I'm pressed tonite, but this caught my eye.

http://www.livescience.com/animalworld/top10_vestigial_organs.html

 10) Flightless birds. Show me one flightless bird that doesn't use it's wings.. Every species has a use wether from courtship, to diving in the water, to balancing themselves on fast runs, camoflague.. You name it, they use them and they are FAR from useless.

9) Hind legs in whale. First, note how blurry the un-clicakble inlay is, even though it instructs you to view the inlay. Second, they've only found two specimines total that looked anything like a leg bone, not beyond the realm of a tumor or anomolus genetic defect. Third: These uniform bones in modern whales are important anchors for the reproductive organs.

8 ) erector pili . Or goosebumps. These are VERY important to sex in humans. Imagine if your girl didn't get erect nipples. Need I say more? (Sorry if this is a family show.)

7) human tailbone : Important anchor for buttox muscles.

6)The Blind Fish Astyanax : I'm not sure that absolute darkness wouldn't do this to many species.

5)  Wisdom Teeth : I'm not sure this isn't an inbred genetic trait in humans. A) It doesn't affect all people. B) Inbred hicks often have messed up teeth.

4)Dandelions. Have sex organs which they "don't use" but clone themseleves instead. A) They do use them to attract bees and ants which benefit from their pollen and B) in turn they are protected from other insects. C) I'm not so sure they don't use them for normal flower sex as well. D ) There are species of Dandelion that do reproduce normally.

3) Fake lizard sex: No comment, interesting. Some species of sea fish actually are all female and one of the dominant females begins producing testosterone and becomes the male, litterally.

2) Male breast tissue(nipples). It is my understanding that we are all female in the womb untill the DNA codes differentiate us as sexes. So not all tissue is removed. Saying it is vestigial seems to imply that humans will evolve and lose them. I don't think that will happen.

1) Human Appendix : The Encyclopedia Britainica (forget  wich year, sometime in the 90's described the appendix as the place where digestive, immune responses start. I'll see if I can find a link.

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Re: Evolution in action?
« Reply #101 on: March 23, 2007, 08:20:56 pm »

I'm pressed tonite, but this caught my eye.

http://www.livescience.com/animalworld/top10_vestigial_organs.html

 10) Flightless birds. Show me one flightless bird that doesn't use it's wings.. Every species has a use wether from courtship, to diving in the water, to balancing themselves on fast runs, camoflague.. You name it, they use them and they are FAR from useless.

Vestigal doesn't mean that it's not used for anything.

http://en.wikipedia.org/wiki/Vestigal_organ
Quote
Vestigial structures are anatomical structures of organisms in a species, which have lost much or all of their original function through evolution. They are typically in a degenerate, atrophied, or rudimentary condition. They are often called vestigial organs, although not all of them are actually organs.

Although structures usually called "vestigial" are largely or entirely functionless, a vestigial structure may retain lesser functions or develop new ones.[1] Thus, a "vestigial wing" is one useless for flight, but may serve some other purpose.



9) Hind legs in whale. First, note how blurry the un-clicakble inlay is, even though it instructs you to view the inlay. Second, they've only found two specimines total that looked anything like a leg bone, not beyond the realm of a tumor or anomolus genetic defect. Third: These uniform bones in modern whales are important anchors for the reproductive organs.


Quote
There are many cases where whales have been found with rudimentary hind limbs in the wild, and have been found in baleen whales, humpback whales, and in many specimens of sperm whales. Most of these examples are of whales that had only leg bones, but there were some that included feet with complete digits.


8 ) erector pili . Or goosebumps. These are VERY important to sex in humans. Imagine if your girl didn't get erect nipples. Need I say more? (Sorry if this is a family show.)

I don't see how that would matter, it might matter in breast feeding though. But are the erector pili responsible for erect nipples?


7) human tailbone : Important anchor for buttox muscles.

Again vestigal doesn't mean it's absolutely not used for anything.


6)The Blind Fish Astyanax : I'm not sure that absolute darkness wouldn't do this to many species.

Well the point is that they have a vestigal eye.


5)  Wisdom Teeth : I'm not sure this isn't an inbred genetic trait in humans. A) It doesn't affect all people. B) Inbred hicks often have messed up teeth.

Inbred genetic trait? I dont't see any basis for that. And I don't really think many "hicks" are inbred. And even if they have teeth problem it's probably due to their lifestyle.


4)Dandelions. Have sex organs which they "don't use" but clone themseleves instead. A) They do use them to attract bees and ants which benefit from their pollen and B) in turn they are protected from other insects. C) I'm not so sure they don't use them for normal flower sex as well. D ) There are species of Dandelion that do reproduce normally.

Again, vestigal doesn't mean not used for anything.


3) Fake lizard sex: No comment, interesting. Some species of sea fish actually are all female and one of the dominant females begins producing testosterone and becomes the male, litterally.




2) Male breast tissue(nipples). It is my understanding that we are all female in the womb untill the DNA codes differentiate us as sexes. So not all tissue is removed. Saying it is vestigial seems to imply that humans will evolve and lose them. I don't think that will happen.


Yes they even mention the fact that we're "sexless" early in the womb, but it's still vestigal.

1) Human Appendix : The Encyclopedia Britainica (forget  wich year, sometime in the 90's described the appendix as the place where digestive, immune responses start. I'll see if I can find a link.


That seems to be debated. Either way, vestigal doesn't mean useless. And it's interesting that there were 300,000 appendectomies 2000 in USA.
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Re: Evolution in action?
« Reply #102 on: March 24, 2007, 02:09:06 am »

We both link Wikipedia articles but this should be noted.

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

Wikipedia isn't the most reliable source of information.
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Re: Evolution in action?
« Reply #103 on: March 25, 2007, 12:20:47 pm »

We both link Wikipedia articles but this should be noted.

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

Wikipedia isn't the most reliable source of information.
Yes that's true. Wikipedia articles may be incorrect, but very often there are references to different sources and you can often find other web pages to back up the information.

For example the definiton of a vestigial organ seems to be agreed on, even Darwin said they didn't have to be useless.
http://www.talkorigins.org/faqs/quotes/scadding.html
http://www.talkorigins.org/faqs/comdesc/section2.html#vestiges_functional
http://216.239.59.104/search?q=cache:WR_x_70TA9kJ:wiki.cotch.net/index.php/E...rip=1
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Re: Evolution in action?
« Reply #104 on: March 25, 2007, 07:11:04 pm »

Quote
I was basing that claim on this:
http://en.wikipedia.org/wiki/Punctuated_equilibrium
Which says that evolution happens quickly, in leaps, between periods of relative staticity.

Punctuated Equilibrium is a minority view among evolutionists and hotly contested with it's own set of problems.

http://www.talkorigins.org/faqs/punc-eq.html


Quote
I don't think we'd see that clearly delimited species, the change is more gradual.

Now isn't this the issue between gradualism and punctuated equilibrium?


Quote
Well fossils do take some special circumstances to form and who knows how many fossils are left out there. But what's interesting is that we're constantly finding new fossils that appear to be "missing links". I just did a search on Google news quickly:

That's just it, we are NOT constantly finding new fossils that appear to be missing links. We are finding many more animals that do not fit into the tree of life and completely different phyla.

Quote
March 22 2007:
http://www.theage.com.au/news/national/cave-may-hold-missing-link/2007/03/21/1174153159560.html
Quote
Cave may hold missing link
"It represents a kind of stepping stone between very primitive insects and praying mantids," he said. "Or it might be a completely new kind of insect."

This is a completely new insect and just because it's genome is more consistent with the praying mantis than a cockroach is irrelevant. The two genomes of any given frog species can have many times the difference between the genome of a bat and a blue whale.

Quote
March 14 2007:
http://www.pittsburghlive.com/x/pittsburghtrib/news/breaking/s_497722.html
Quote
A fossil of a newly-discovered, chipmunk-sized mammal that roamed the world with the dinosaurs 125 million years ago provides a missing link in the evolution of the middle ear, according to a researcher at the Carnegie Museum of Natural History.


So because my TV has a circuit board and my car has a circuit board one evolved from the other?

Quote
March 2 2007::
http://www.associatedcontent.com/article/166059/fossil_find_may_be_one_of_oldest_ever.html
Quote
It could be a "missing link" to the evolution of cuttlefish, squids, and octopus.

Could be? Why EXACTLY is it a missing link? Because it's old? Because it fits the same phyla? Because of the FACT of evolution and that cuttlefish, squids and octopus had to evolve from a common ancestor?

Quote
If educated people working in that field sees a specific feature that only exists within a certain group then I'd say the animal also belongs to that group. From what I understand they've also done genetic testing. It seems it evolved from some sort of hippopotamus and evolved to the (air-breathing) dolphin. The Ambulocetus natans is also from the same suborder.

http://en.wikipedia.org/wiki/Evolution_of_cetaceans#Pakicetids:_the_earliest_cetaceans.3F
Quote
The shape of the ear region in Pakicetus is highly unusual and only resembles the skulls of whales. The feature is diagnostic for cetaceans and is found in no other species.
According to Thewissen, the teeth of Pakicetus also resemble the teeth of fossil whales, which is another link to more modern whales.[3]

Dude they determined it was a ancestor to modern dolphins based on a skull and similarties in the inner ear. They determined that Tiktaalik was a walking mammal when the only remains they had was a skull, nothing more.  they haven't found a complete skeleton. How do we know it wasn't an ancient whale/dolphin species?


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That's true, it may not be a proper missing link. But there are 46 others on that list and like I said, it seems like we just keep finding new ones. And also the Archaeopteryx which you agreed is a very plausible missing link.

Most of the 46 others are superficial bone differences not outside the realm of limited, microevolution. And even though Archaeopteryx is a plausible missing link, doesn't mean it is one. The Duckbilled platupus is among a very few species of egg laying mammals yet nobody is casting these living animals as missing links between reptiles or birds to mammals.

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Yes but that theory "punctuated equilibrium" seems to coroborate that. There is much stasis and then quick bursts of evolution, kind of "the last drop". When it happens it happens alot in a short time, like a dam breaking. Also if one species evolves a specific benefit it may cause a sort of "arms race" because the pressure on other species will increase rapidly. So evolution may also fuel itself.

As stated before, PE is fraught with it's own problems and is not a widely accepted paradigm.

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I don't know how complex an "eye" that refers to, but here's another explanation:
http://en.wikipedia.org/wiki/Photoreceptor_cell

That isn't the entire eye but what takes place inside a single human photoreceptor cell. Since you argue that the human eye is built from "simple" to more complex I thought I'd show just how "simple" a single photo receptor cell is. We see precision and purpose from the most minute microscopic detial of our modern eye to the largest features such as eyelids, control muscles, tear ducts etc.

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I don't know how primitive a cell could be to only be able to detect light. But photons do impact and affect cells creating some kind of reaction.


It's not just "some kind of reaction" but a highly prefected interaction of specific and complex protiens and enzymes. We see specific functions at every level of complexity conspiring to achieve vision regardless of how "simple" the eye itself is.

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Also photosynthesis is strongly connected to light and light sensitivity. Just think about algae and some bacteria.

Oranges and apples. Photosyhthesis is a process by which plants and algea turn sunlight into useable energy. "light sensetivity" as you marginalize this complex and specifc function we call sight, has nothing to do with photosynthesis and turns photonic information into electirical signals to be interpreted by the brain.

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I found some links when Googling around:
http://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html

That whole link is a just-so story built around darwinian dogma. I especially liked this:

"And, according to one scientist's calculations, only 364,000 years would have been needed for a camera-like eye to evolve from a light-sensitive patch. "

I'd like to see this guy's calculations...

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Once again, interesting but conclusive? Only if you are a firm believer in the "fact" of evolution. It's fascinating that lizards see in two colors but can we really conclude much more than that ?

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"So cubozoan eyes are good for spotting large, stationary objects, while filtering out unnecessary detail such as plankton drifting with the current.

So the jellyfish eyes are specialized to their environment. Specifed and purposeful.

"From here it would be an easy step to evolve an image-forming eye."

Well if it's any easy step then by all means demonstarte it in the lab!!! I love the darwinist's magic wand, happily skipping over  volumes of complexity with the wave of a hand.

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Did you follow the link in that wiki article?

http://news.nationalgeographic.com/news/2001/08/0822_starfisheyes.html

Scientists have discovered a species of brittle star whose outer skeleton is covered with crystalline lenses that appear to work collectively as an all-seeing eye. ...

"These lenses have exceptional optical performance," said Aizenberg, who is co-author of a report on the discovery published in the August 23 issue of Nature. "They are compensated for physical effects that bother us when we fabricate lenses in the laboratory"—effects known as birefringence and spherical aberration.

So how does this fit with the evolution from light sensetive cell to modern complex shutter camera eyes of humans?

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a light-sensitive patch will gradually turn into a focused lens eye through continuous small improvements of design

Show me the emperically testable evidence please.


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Covered this earlier.

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The evolutionary computer program called ALife is a simple computer program designed to succeed and is not really a realistic example of evolution though random mutation and natural selection. Natural selection is not an absolute series of IF THEN statements that will weigh in favor of a given function every time. Further more, the AND, XOR , EQU etc. functions that the program rewards were written ahaed of time and represent easy to evolve 3 sequence of characters. Protien sequences are at leats 50 amino acids in length or larger and each amino acid sequence is written by 3 base pairs in the DNA structure.


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"The idea is simply that you fiddle around and you change something and then you ask, Does it improve my survival or not? And if it doesn't, then those individuals die and that idea goes away. And if it does, then those individuals succeed, and you keep fiddling around, improving. It's an enormously powerful technique."

It is indeed a powerful idea. But if you can "simply fiddle around" why does it reamin so elusive in the lab?

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I'll look at these later..

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And I'm sure there's much more. But the idea is like with the eye, gradual evolution.

In these links you provided I see references to gradualism but I have yet to read anything regarding expirimental science confirming such speculation. Thats all it is, speculation and just-so stories based around a centeral evolutionary idea.

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Again theories like punctuated equilibrium agree with that. And fossil formation is a rare occurence.
Punctuated Equilibrium is the opposite of gradualism so it doesn't "agree with that".

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Well they claim that Rhagoletis pomonella is becoming a separate species. Then there's the Nylonase. And what about the pig or the dog? So we can certainly get new species. There probably are problems with breeding a dolphin to the size of a blue whale for example, the physiology of the animal may not be compatible with such a big size.

Human populations have lived in realitive isolation for thousands of years. Micro evolution is evident. Africans, Chinese and Europeans for example exhibit distinct characteristics. So according to this logic, if humans remained isolated they would eventually become a different species. Somthing I don't think will ever occur. This idea is a centeral theme to Darwin's gradualism but unfortunately has never been documented or reproduced in a lab in any capacity.

Even bacteria which we can reproduce into the trillions upon trillions of generations and witness real time mutation by sequencing their genome never produce anything but the same species. It's a pipe dream man, I'm telling ya.

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Once again, yeast cells produce nothing novel morphically and are just more yeast cells with some unique genetic characteristics. They even admit to microevolutionary changes.

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Sigh.. Really? Two isolated "species" of frog creating a hybrid. So what, where's the evolution? If they can interbreed then they aren't a seperate species to begin with.

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There is science behind this.
http://www.utexas.edu/courses/wilson/ant304/projects/projects97/weimanp/fossils.html
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Whatever the cause of bipedality, it eventually led to the development of higher intelligence. Darwin's theory is that with the freed up hands that bipedality allows, hominids would be able to use tools, and the use of tools led to the development of greater intelligence.

Sigh..Bipedabilty requires some sophisticated hardware, especially in the inner ear and the equilibrium of the species. Not only that, just because our hands were "freed up" doesn't mean we had the intelligence to use tools. This is one of those just-so stories that really isn't backed by anything other than believing the "fact" of evolution.

.. that's all I have time for today.

btw. About goosebumps on humans. Think what happens to the human body while in cold water. Especially if you are a man. The body has an interesting way of conserving heat.
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