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Author Topic:   Evolving the Musculoskeletal System
DrJones*
Member
Posts: 2284
From: Edmonton, Alberta, Canada
Joined: 08-19-2004
Member Rating: 6.8


Message 181 of 527 (578757)
09-02-2010 2:18 PM
Reply to: Message 179 by ICANT
09-02-2010 1:45 PM


Re: Great Potential
The Coelacanth that was supposed to have lived in shallow water and finally walked up on land and became the first living land creature has remained basically the same for the past 410 million years. Where is the mutations?
The 2 species of coelacanth living today are not found in the fossil record.

It's not enough to bash in heads, you've got to bash in minds
soon I discovered that this rock thing was true
Jerry Lee Lewis was the devil
Jesus was an architect previous to his career as a prophet
All of a sudden i found myself in love with the world
And so there was only one thing I could do
Was ding a ding dang my dang along ling long - Jesus Built my Hotrod Ministry

Live every week like it's Shark Week! - Tracey Jordan
Just a monkey in a long line of kings. - Matthew Good
If "elitist" just means "not the dumbest motherfucker in the room", I'll be an elitist! - Get Your War On
*not an actual doctor

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crashfrog
Member (Idle past 1466 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


(1)
Message 182 of 527 (578785)
09-02-2010 3:45 PM
Reply to: Message 179 by ICANT
09-02-2010 1:45 PM


Re: Great Potential
Do you have some studys that back up this particular statement?
This is really such an obviously true thing that the scientific proof of it predates the notion of academic peer review. Chemical reactions have long been known to be stoichiometric, that is to say that their outcomes are statistical and not deterministic, which means that the mechanism of DNA replication is necessarily one in which changes - mutations - must occur.
They're not allowed to occur by something - it's impossible to prevent them from occurring. The fidelity of the replication process can be increased or decreased, and in most cells the fidelity is very high, but just as in any process of information transfer, there's a level of entropy that introduces changes. In a radio signal those changes are called "static." In a DNA sequence those changes are mutations. And unlike in a radio signal, where there can be so much static that the signal itself is lost, any mutation to a DNA sequence is still a DNA sequence, which the cell is going to try to interpret as a protein.
The famous fly Drosophila melanogaster study suggest that a protein change by a gene will be harmeful about 70% of the time, having damaging results even death. The remaining 30% will either be netural or weakly beneficial.
No, you're wrong about this. Precisely backwards. 70% of protein changes will have no effect at all; only 30% or less will have any effect, harmful or beneficial, on protein function.
The vast bulk of a protein is structural, only generally involved in protein configuration, and any individual amino acid residue's contribution to protein structure is necessarily going to be very small. Proteins can have hundreds or even thousands of residues. The largest monomer protein (titin, a muscle protein) is comprised of over 34,000 amino acid residues, but only about a hundred or so are critical to the function of the protein (and are thus highly conserved.)
The Coelacanth that was supposed to have lived in shallow water and finally walked up on land and became the first living land creature has remained basically the same for the past 410 million years.
Coelacanths didn't become "the first land creatures."
A much better example of a water-to-land transitional is Tiktaalik.
As for the rest, you're quite wrong. Today's horseshoe crabs are substantially different than their fossil ancestors. Today's cockroaches have substantial biochemical adaptations that their ancestors lacked (a big problem for your local Orkin man, trust me.) And, of course, the modern Coelacanth is about a fifth of the size of any of its evolutionary precursors.
And where are the mutated horseshoe crabs? Mutated so much, they're nothing like horseshoe crabs anymore. Where are the mutated cockroaches? Mutated so much, they're called "termites" now.
Since this is a fact some scientist developed the Theory of Punctuated Equilibria.
Punctuated Equilibria
quote:
PE is not mutually exclusive of phyletic gradualism. Gould and Eldredge take pains to explicitly point out that PE is an expansive theory, not an exclusive one (1977).
PE sometimes is claimed to be a theory resting upon the lack of evidence rather than upon evidence. This is a curious, but false claim, since Eldredge and Gould spent a significant portion of their original work examining two separate lines of evidence (one involving pulmonate gastropods, the other one involving Phacopsid trilobites) demonstrating the issues behind PE (1972). Similarly, discussion of actual paleontological evidence consumes a significant proportion of pages in Gould and Eldredge 1977. This also answers those who claimed that E&G said that PE was unverifiable.

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Replies to this message:
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Blue Jay
Member (Idle past 2697 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


Message 183 of 527 (578802)
09-02-2010 4:53 PM
Reply to: Message 179 by ICANT
09-02-2010 1:45 PM


Re: Great Potential
Hi, ICANT.
I think Taq and Crash are better qualified to discuss with you the biochemistry of mutations and their place in evolution, so I’ll yield the floor to them on that topic.
But, I do want to weigh in on a couple of things:
ICANT writes:
I thought an accident was required for the DNA to mutate.
If you thought accidental mutations were required, why did you ask this:
ICANT writes:
Wouldn't it require the DNA to give the order to make a little change in the structor of the foot?
Now if the DNA had the informtion stored in it there would be no problem.
But how could all the necessary orders be given to create that great potential of variation?
Message 93
-----
ICANT writes:
How am I doing so far?
How are you doing on what?
On listing random points about mutation? Meh. I defer to Taq and Crash to pass judgment.
On staying on topic? Not too well, I’m afraid.
-----
ICANT writes:
The Coelacanth that was supposed to have lived in shallow water and finally walked up on land and became the first living land creature has remained basically the same for the past 410 million years. Where is the mutations?
The Horseshoe crab has been around for 425 million years and remains the same today. Where is the mutations?
The cockroach is the oldest winged insect in the world and appears some 350 million years ago, and remains the same today. Where is the mutations?
I swear we’ve been through these exact points before. You can’t seriously tell me that you don’t know the answers to these already.
Since the topic is about the musculoskeletal system of vertebrates, we should focus on fish and tetrapods, but, since neither Taq nor Crash really responded in-depth to the cockroach, I would like to do so.
There were no cockroaches 350 million years ago. In the Carboniferous period, there were Blattopterans (sometimes called ‘roachoids’). They look a lot like cockroaches, but they have ovipositors (egg-laying tubes), and didn’t have the organs for creating oothecae (egg-cases). Furthermore, these Blattopterans are also the ancestors of termites and mantids. I also invite you to peruse this page, which displays pictures of different families of cockroaches, and this picture, which depicts a mantis that looks a whole lot like a cockroach.
But, I digress. Let’s get back to the fish:
I know for a fact that you have argued this line about coelacanths before, and that you have been told that it is inaccurate. Coelacanths are not the ancestors of tetrapods, probably never came out on land, and have not existed unchanged for millions of years in the fossil record. They are not a good example of stasis in the fossil record.
Coelacanths are lobe-finned fish, like modern lungfish, and the ancient ancestors of tetrapods. Earlier on this thread, I showed a diagram of the limbs of various lobe-finned fish:
It is clear from this diagram that there were all kinds of little bones in the limb of the fish that went through a number of experimental configurations (see Sauripterus), culminating in the configuration used by Tiktaalik (which already shows a lot of similarities with tetrapod limbs), before shifting into the configuration used by the earliest tetrapods. In both the case of Tiktaalik and the earliest tetrapods, it is straightforward to pick out which bones would gradually become the radius, ulna, carpals, metacarpals and phalanges (the individual arm bones of humans and other tetrapods).
This is the sequence I pointed out to you, that you thought was difficult to envision outside of a fantasy world: (1) scattered bits of bone in the limb; (2) organization of the bits of bone; (3) modification of the pattern to match modern-day tetrapod patterns.
It seems pretty obvious to me that the same thing explains the emergence of the original pattern of bones. It has been pointed out on this thread that primitive fish only have bones in some parts of their body, and that some fossilized proto-fish have even less bone or none at all. The tendency to form bones would increase as fish evolved, until they had complex skeletons full of unique bones, which could then be altered to form tetrapod limbs.

-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.

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caffeine
Member (Idle past 1024 days)
Posts: 1800
From: Prague, Czech Republic
Joined: 10-22-2008


Message 184 of 527 (578935)
09-03-2010 4:42 AM
Reply to: Message 182 by crashfrog
09-02-2010 3:45 PM


The varieties of coelacanth
And, of course, the modern Coelacanth is about a fifth of the size of any of its evolutionary precursors.
I think you go a bit confused here - fossil coelacanths range in size from tiny to massive. Modern coelacanths have a total length of between about 4' and 6'. Coelacanthus, the type genus, were no longer than 3'. Polyosteorhynchus doesn't seem to have gotten any bigger than 7" or so, while giant Cretaceous coelacanths like Megalocoelacanthus have been discovered with lengths up to 11'.
Clearly though, coelacanths haven't remained the same as time has gone by.

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Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003
Member Rating: 8.7


(1)
Message 185 of 527 (578936)
09-03-2010 4:47 AM
Reply to: Message 179 by ICANT
09-02-2010 1:45 PM


Punctuated Equilibrium is wrong and misrepresented
The fossil record does not support evolution by mutation and natural sellection.
The observation of the fossil record supports that species are amazingly conservative and stasis for long periods of time.
Since this is a fact some scientist developed the Theory of Punctuated Equilibria.
Eldredge, N. and Tattersall, I. (1982) in "The Myths of Human" Evolution Columbia University Press, p. 48 says: "The record is there, and the record speaks for tremendous anatomical conservatism. Change in the manner Darwin expected is just not found in the fossil record."
Gould, S.J. (1977) in "Evolution's Erratic Pace" Natural History, vol. 86, May says:
"The history of most fossil species include two features particularly inconsistent with gradualism:
1) Stasis - most species exhibit no directional change during their tenure on earth. They appear in the fossil record looking much the same as when they disappear; morphological change is usually limited and directionless;
2) Sudden appearance - in any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and 'fully formed'."
A species appearing fully formed all at once supports creation, not evolution.
Firstly, Gould and Edlredge were wrong. Punctuated Equilibrium as a theory is discredited*. He were wrong that mophological change occurs only at speciation, he were wrong that statis followed by sudden change is the dominant pattern of the fossil record and they were wrong in asserting that where observed it represents an accurate picture of the rate and pattern of actual change in the organisms (in the same way that someone looking at a series of images of people walking from a camera taking photos only once every 10 seconds would be wrong to conclude that the people were moving suddenly from place to place rather than smoothly between points).
Secondly, your interpretation about what Gould is saying is wrong. Gould is not saying that dramatically different organisms spring forth suddenly in the fossil record. The thing you must realise is that species are generally very similar. Many species can only be easily distinguished by experts. Gould is not talking about an organism suddenly sprouting wings (say), he's talking about a shell acquiring a new ridge in a geological blink of an eye.
Thirdly, you've again stumbled over the fully-formed canard. Evolution does not predict half-formed creatures! It predicts that all species that have ever survived for any length of time are well adapted to their environment and successfully reproducing in it.
* - Punctuated equilibrium has brought some ideas into evolutionary theory. In particular, it's now widely recognised that evolutionary change is very variable in rate and can be very fast (something that would not have surprised Darwin), and there has been a considerable amount of investigation into stasis. But Gould and Eldredge's overblown claims for the idea are simply not supported by the evidence.
Edited by Mr Jack, : Forgot footnote.

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ICdesign
Member (Idle past 4797 days)
Posts: 360
From: Phoenix Arizona USA
Joined: 03-10-2007


Message 186 of 527 (579049)
09-03-2010 12:59 PM
Reply to: Message 172 by Percy
09-02-2010 8:22 AM


Re: Seeking to understand basis for incredulity
Hi Percy. Thanks for taking the time to share you thoughts with me
Percy writes:
The first "organism" was probably just a collection of chemicals held within some kind of membrane, and that "organism" was "fully formed."
This is wild speculation with no evidence to support such a claim. If it started with chemicals it should be repeatable with chemicals....or let me guess, those chemicals conveniently no longer exist right?
And how did that "organism" become fully formed? ...just dumb luck at its best I guess.
If you guys want to believe such a fairy-tale as all of this that's fine but lets quit calling it science.
It qualifies as a fable and no more.
Percy writes:
The important point to take from this is that evolving a new feature takes many, many generations, and that at each point along the way the change must provide some advantage, otherwise it won't be selected and will be lost
I don't mean this in a disrespectful way Percy. I have great respect for you and I like you but all I am taking away from this is a bunch of double talk and no clear explanations for my previous questions. I feel like I am sitting in on a David Copperfield show or something.
If you're using people as an example
...we don't need to use people as an example. Lets go back when fish hit the land and the skeletal system was in the process of evolving.
I am very unclear how changes show up in each off spring.
How does a new bone show up as it is in the process of development? Maybe it would be easier if you pointed me to a web-site that has lots of pictures. Seems like all I ever see and hear are broad generalizations.
I can't imagine any selection pressure that would select for something that might eventually become a new skeletal body part
I am also very unclear about selection pressure. Can you direct me to a source that explains what this "pressure" is, what reads it, and how it directs design please?
Respectfully,
IC

This message is a reply to:
 Message 172 by Percy, posted 09-02-2010 8:22 AM Percy has replied

Replies to this message:
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ICdesign
Member (Idle past 4797 days)
Posts: 360
From: Phoenix Arizona USA
Joined: 03-10-2007


Message 187 of 527 (579050)
09-03-2010 1:07 PM
Reply to: Message 177 by Taq
09-02-2010 12:00 PM


Re: Seeking to understand basis for incredulity
Hi Taq,
Taq writes:
You have been taught about the the birds and the bees, have you not?
Yes I have. I was taught that bees give birth to bees and birds give birth to birds.
The ToE violates this simple law over and over and over again which is all the proof I need that this theory is 100% impossible.
Thank you,
IC

This message is a reply to:
 Message 177 by Taq, posted 09-02-2010 12:00 PM Taq has replied

Replies to this message:
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Coyote
Member (Idle past 2105 days)
Posts: 6117
Joined: 01-12-2008


Message 188 of 527 (579051)
09-03-2010 1:07 PM
Reply to: Message 186 by ICdesign
09-03-2010 12:59 PM


Re: Seeking to understand basis for incredulity
How does a new bone show up as it is in the process of development?
How about cartilage?

Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

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 Message 186 by ICdesign, posted 09-03-2010 12:59 PM ICdesign has not replied

  
Taq
Member
Posts: 9970
Joined: 03-06-2009
Member Rating: 5.6


Message 189 of 527 (579053)
09-03-2010 1:12 PM
Reply to: Message 187 by ICdesign
09-03-2010 1:07 PM


Re: Seeking to understand basis for incredulity
Yes I have. I was taught that bees give birth to bees and birds give birth to birds.
As does the theory of evolution. We are apes, as was our common ancestor with other apes. Apes giving birth to apes. So I would hazard a guess that you don't have a problem with that?
Also, fish are vertebrates and we are vertebrates, as was our common ancestor. Vertebrates giving birth to vertebrates. So I would assume you have no problem with this either?

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jar
Member (Idle past 393 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 190 of 527 (579056)
09-03-2010 1:16 PM
Reply to: Message 186 by ICdesign
09-03-2010 12:59 PM


Re: Seeking to understand basis for incredulity
This is wild speculation with no evidence to support such a claim. If it started with chemicals it should be repeatable with chemicals....or let me guess, those chemicals conveniently no longer exist right?
And how did that "organism" become fully formed? ...just dumb luck at its best I guess.
Of course there is evidence. A great example is that in the oldest known rocks there are chemicals but no signs of life. We can say with a very high degree of confidence that chemical reactions were going on before there was life.
And yes, if life started as a chemical reaction it should be repeatable. And guess what, that is exactly what is being done in the Science of Abiogenesis.
By definition, organisms are always fully formed.

Anyone so limited that they can only spell a word one way is severely handicapped!

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Huntard
Member (Idle past 2294 days)
Posts: 2870
From: Limburg, The Netherlands
Joined: 09-02-2008


Message 191 of 527 (579063)
09-03-2010 1:26 PM
Reply to: Message 186 by ICdesign
09-03-2010 12:59 PM


Re: Seeking to understand basis for incredulity
ICDESIGN writes:
This is wild speculation with no evidence to support such a claim.
If you mean we have found the organism then, no, we haven't, would be kinda hard. However, since all life seems to be based around chemistry, and in the oldest rock layers, we see only very simple critters or single celled organisms, we infer that the earliest life was a very basic chemical "soup" in a membrane.
If it started with chemicals it should be repeatable with chemicals....or let me guess, those chemicals conveniently no longer exist right?
Oh, no, they are still around, and experiments are underway to see if we can indeed replicate it. So far, no complete organism has been produced yet, but we're getting ever closer. Remember, just because we can't do it today doesn't mean we will never be able to do it
And how did that "organism" become fully formed? ...just dumb luck at its best I guess.
No. there are very precise laws concerning chemistry. Which is why you always get iron rusting (for example).
If you guys want to believe such a fairy-tale as all of this that's fine but lets quit calling it science.
It qualifies as a fable and no more.
Well, we don't believe what you're saying we believe, though.
I don't mean this in a disrespectful way Percy. I have great respect for you and I like you but all I am taking away from this is a bunch of double talk and no clear explanations for my previous questions. I feel like I am sitting in on a David Copperfield show or something.
Would it help if we took it step by step? I.e. you ask a question, and we give the answer, than you ask a question again and we give the answer, and so forth. Don't make it anything to big (from both sides), and we should be alright, yes?
...we don't need to use people as an example. Lets go back when fish hit the land and the skeletal system was in the process of evolving.
They already had a complete skeleton at that point. Yes, it was different from ours, but for it was as complete as any skeleton is complete today for any critter.
I am very unclear how changes show up in each off spring.
Gradually. Step by step.
How does a new bone show up as it is in the process of development?
It doesn't "show up" as a whole new bone, or part of a new bone (say, half a femur) in this instance. By the time we are at this stage in evolution, everything that follows is a modification of the already present skeleton.
Maybe it would be easier if you pointed me to a web-site that has lots of pictures. Seems like all I ever see and hear are broad generalizations.
Hmm. Let's see. This one is about horse evolution, and illustrates the modifications to the horses leg bone and teeth over about 50 million years:
(Start from bottom)
This is from the wiki article about horse evolution. Now, not all these critters are direct ancestors of each other, but I hope you get an idea of the process we have in mind.
I am also very unclear about selection pressure. Can you direct me to a source that explains what this "pressure" is, what reads it, and how it directs design please?
I'll try to explain myself first. Simply put, the selection pressure is the environment the critter lives in. For example, if the critter lives in a mainly purple coloured environment, but is grey, there is of course a big risk of being spotted by predators. Now, say, that by a mutation, a critter is born that has a purple pelt. It will of course be much easier for this critter to elude its predators. This will result in it being able to reproduce better and as a result it's purple offspring (they inherited this trait from their parent), will also be able to reproduce better, until ultimately every critter in the population is purple. This is the "pressure" for "being purple" (in this case) that we mean with natural selection, or selection pressure.

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 Message 186 by ICdesign, posted 09-03-2010 12:59 PM ICdesign has not replied

  
Percy
Member
Posts: 22388
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


(1)
Message 192 of 527 (579066)
09-03-2010 2:06 PM
Reply to: Message 186 by ICdesign
09-03-2010 12:59 PM


Re: Seeking to understand basis for incredulity
ICDESIGN writes:
If you guys want to believe such a fairy-tale as all of this that's fine but lets quit calling it science. It qualifies as a fable and no more.
Making inferences from evidence is what science does.
Percy writes:
The important point to take from this is that evolving a new feature takes many, many generations, and that at each point along the way the change must provide some advantage, otherwise it won't be selected and will be lost
I don't mean this in a disrespectful way Percy. I have great respect for you and I like you but all I am taking away from this is a bunch of double talk and no clear explanations for my previous questions. I feel like I am sitting in on a David Copperfield show or something.
I can tell by the references to "double talk" and "David Copperfield" that you don't accept what I told you, but you provide no indication why. Can you be a bit more specific? What I described was just a couple basic evolutionary principles, and if you can explain what it is that makes them difficult for you to accept then I could respond to that.
I am very unclear how changes show up in each off spring.
Offspring are not identical to their parents because the genetic copying that takes place during reproduction is imperfect. Every offspring has its own unique set of mutations. Mammalian genomes usually have billions of base pairs, and a common rough estimate of the average number of mutations in offspring is around a hundred. That's an error rate of one in ten million. These errors represent a tiny, tiny change. To the extent that the difference provides a survival advantage it will be selected for because the organism will be more likely to produce offspring or will produce more offspring than others of its species, and the changes will become more and more represented in the population in subsequent generations. To the extent that the difference confers a survival disadvantage it will be selected against because the organism will be less likely to produce offspring or will produce less offspring than others of its species, and those changes will become less and less well represented in the population in subsequent generations.
How does a new bone show up as it is in the process of development?
By "development" you mean evolutionary change? If so, then new bones are unlikely to show up in complex creatures like ourselves, though there are ways it can happen. I think someone showed a picture of a boy with six fingers, so duplication is one way to produce new bones in a wholesale fashion.
But if you're asking how a bone first begins from scratch then possibilities were described earlier in this thread. Start at Message 173 and read back. But again, it seems unlikely to happen in complex creatures. It is much more likely in the earliest multi-celled life as body plans were evolving. Our evolutionary descendants are going to be pretty much stuck with the current body plan of 2 arms and 2 legs and all that.
I am also very unclear about selection pressure. Can you direct me to a source that explains what this "pressure" is, what reads it, and how it directs design please?
Selection is just a natural and inevitable process. All reproduction is imperfect. If the imperfections confer a disadvantage, such as an arctic hare that loses the ability to turn white in winter, then the creature will be less likely to survive to produce offspring and the trait will be rare and probably go extinct. If the imperfections confer an advantage, such as a hawk with more closely spaced retinal cells for higher resolution, then the creature will be more likely to survive to produce offspring and the trait will become more common in the hawk population.
Notice there's nothing directing the process. Advantageous traits give a creature a competitive advantage, and so through the generations you'll gradually see more and more creatures with that trait. The opposite is true for disadvantageous traits - they'll tend to disappear from a population.
--Percy

This message is a reply to:
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Blue Jay
Member (Idle past 2697 days)
Posts: 2843
From: You couldn't pronounce it with your mouthparts
Joined: 02-04-2008


(1)
Message 193 of 527 (579070)
09-03-2010 2:23 PM
Reply to: Message 186 by ICdesign
09-03-2010 12:59 PM


Re: Seeking to understand basis for incredulity
Hi, ICDESIGN.
You're asking a lot of good questions here.
ICDESIGN writes:
I am very unclear how changes show up in each off spring.
How does a new bone show up as it is in the process of development?
Bones are produced by a number of different genes acting together.
There are some genes that cause minerals to be collected and deposited, creating bones.
And, there are some genes that direct where and when the minerals are to be deposited.
This second group of genes is important, because they produce the patterns that define how the skeleton forms during the development of the embryo.
When these genes are mutated, they often result in different patterns of bone deposition. Sometimes they cause an extra finger (as has been shown in previous posts), or maybe just an extra bone somewhere. Sometimes they cause a bone to not develop fully, or to develop an unusual shape. Sometimes they cause some bones to be longer or shorter than they would be without the mutation.
Several of these types of mutations in gradual succession, with the help of natural selection, could very easily account for the shift from a fish with one configuration of bones in its fin to a fish with a configuration of bones that is similar to Tiktaalik’s, to a tetrapod with a configuration of bones that is similar to ours.
-----
ICDESIGN writes:
I am also very unclear about selection pressure.
It’s just like any other pressure: what doesn’t kill you makes you stronger.
In the case of evolution, it’s mostly just about what kills you, and the makes you stronger is actually only about making the population stronger by favoring the better-adapted and killing or otherwise repressing the lesser-adapted.
Examples of selection pressures can be environmental factors: water supply, climate, food supply, etc., things that organisms have to adapt to in order to survive and flourish.
Also, selection pressures can be antagonists (i.e. predators, parasites, diseases or competitors) that may kill organisms from the population or otherwise interfere with their ability to survive and flourish.
Also, selection pressures can be the preferences of potential mates, which the organism may have to impress in order to get the opportunity to pass its genes on the following generations.
None of this is about what an organism wants or knows it has to do in order to survive and continue its lineage: rather, it’s simply that the organisms that successfully meet these selection pressures will survive and will continue their lineage.
So, selection pressure is just a catch-all phrase for things that cause some organisms to survive and reproduce better than others.

-Bluejay (a.k.a. Mantis, Thylacosmilus)
Darwin loves you.

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crashfrog
Member (Idle past 1466 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 194 of 527 (579092)
09-03-2010 3:30 PM
Reply to: Message 186 by ICdesign
09-03-2010 12:59 PM


Re: Seeking to understand basis for incredulity
Can you direct me to a source that explains what this "pressure" is, what reads it, and how it directs design please?
What "reads pressure"? You'll have to ask that in a clearer way if we're to understand what you could possibly mean by that.
One of the consequences of your open refusal to learn any biological science is that the way in which you speak about biology, and concepts in biology, is all but unintelligible to people who are actually trained in it.
Selection pressure is natural selection - the tendency of organisms well-adapted to their environments to survive, prosper, and reproduce, and the tendency of organisms not so well-adapted to be extinguished and leave no descendants.
When an environment appears to reward a certain adaptation - say, longer necks on grazing creatures in an environment where foliage is lean except at the treetops - we call that a selection pressure that drives that adaptation. Giraffes evolved from short-necked precursors because they lived in an environment that put a selection pressure on having long necks, because shorter-necked individuals starved to death.
Natural selection. Surely you can't be unclear on the notion?
Maybe it would be easier if you pointed me to a web-site that has lots of pictures.
The evolution of bony skeletons predates the invention of photography by several million years. Could you be more specific about what you'd like to see a picture of?

This message is a reply to:
 Message 186 by ICdesign, posted 09-03-2010 12:59 PM ICdesign has not replied

  
scarab
Junior Member (Idle past 4640 days)
Posts: 5
Joined: 06-24-2010


(1)
Message 195 of 527 (579139)
09-03-2010 5:50 PM
Reply to: Message 187 by ICdesign
09-03-2010 1:07 PM


Re: Seeking to understand basis for incredulity
I was taught that bees give birth to bees and birds give birth to birds.
The ToE violates this simple law over and over and over again which is all the proof I need that this theory is 100% impossible.
This is a very important point. It appears to be a key issue that prevents you from accepting the theory of evolution. I imagine that it is a real problem for many people who can not accept the theory of evolution.
You are wrong when you say that the ToE violates your law. Of course you wont believe me if I simply tell you that you are wrong. I bet that you believe that birds are completely different animals from bees. You are wrong about that too but you just don't know it yet. :-)
You think that because birds are completely different things from bees then any common ancestor would have been neither a bird nor a bee. Or, at best, it could have been only one of the two kinds (either a bird or a bee). So even in the friendliest scenario for evolution, a hypothetical ancestor would have had to have changed from one kind into a completely different kind.
That's the only position you could take if you think in terms of completely separate kinds. That is your block, the thing that prevents you from learning how the world works. Your early teaching has blinded you to deeper understanding.
But how could your teaching be wrong? How is that even possible? Kinds don't change into completely separate kinds. That's a fact. How can a fact be wrong? :-) Any theory that says otherwise has got to be wrong. That's obvious.
Lets look at this because its pretty essential and if we don't address it then we are just talking past each other or we are just talking at each other and not to each other.
So how can the fact that kinds don't change into completely different kinds be wrong?
The short answer is that it is not wrong; kinds do not change into completely different kinds. Creationists and evolutionists are in agreement on this point
This is an important point and I don't think that it should be glossed over or ignored. Also, if you disagree with me, if you think that evolutionists do think that kinds change into completely separate kinds then please say so. Let me know if you disagree.
Or if you agree then please say so and we can move on and make more progress.

This message is a reply to:
 Message 187 by ICdesign, posted 09-03-2010 1:07 PM ICdesign has not replied

Replies to this message:
 Message 196 by Percy, posted 09-03-2010 5:57 PM scarab has replied

  
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