If you accept microevolution

[jamesmorlock]

Simply because they are identical.

Consider an analogy:

Imagine that you can travel across the universe by walking. You have an infinite amount of time to do this, but you must make your journey by taking small steps. You have no destination, but you can go anywhere and you must never stop walking.

A thousand years pass. Where are you now? Further.
A million years pass. Where are you now? Even Further.
A billion years pass. Where are you now? Far, far away.

For every iteration of time, you will have traveled further and further. It is inevitable, for every small step takes you further. It is not possible to not travel far.

Microevolution is the small step. Macroevolution is the collective of small steps over a large period of time.

When walking for billions of years, how can you not be far away from your starting point?

[Critical_Thinker]

Critical: Are you asserting that science has NOT observed any new species coming into existence?

btw, are you familiar with ring species?

Hi Autodidact. No, I am not claiming that new species were never observed coming into existence. I believe the definition of a species is defined as “a group of individuals that resemble one
another more than they resemble members of other groups� and “as a group of interbreeding natural populations that are reproductively isolated from other such groups.“ The point that I was attempting to make is that some changes may occur in a species, and sometimes even developing a new species, however, there are limits as to how far the changes could go. Many varieties of fruit flies may evolve but it may not be possible for a fruit fly to gradually, over multiple generations, became a different creature (other than another arthropod) such as having a body plan that a spider or a tick has. I am not aware of any such observance.
In other words, minor, seemingly, insignificant changes may occur in a creature (micro-evolution), but have these minor changes ever been observed that have led up to what would be considered a major change (macro-evolution)? By major change, I mean a fruit fly gradually becoming a spider or a tick. Do you know if it has ever been observed that any creature gradually evolved into a different species with a different body plan?
I am not familiar with ring species. Would you elaborate on this?

You would never observe a fruit fly giving birth to a rutabaga. Evolution predicts that cannot happen. What you would observe is this: A new species arises from descent with modification plus natural selection. You agree that this happens. Another new species arises from that one, by the same process. And another from that one. At some point, the new species is so different from the original one that scientists would say, "This is too different to just classify as a different species. At this point we are going to have to call it a new genus." And this happens again, and again, and again, until you have a new family. And so forth.

So, by its nature, it cannot be directly observed. Only the individual steps can be, and have been, observed. The rest must be deduced from the evidence. The evidence made it clear that this is what happens. I can review that evidence with you if you like; it's interesting and massive.

Hi Autodidact. Thanks for your reply. I suppose from your comment that even though no major change has ever been observed in nature, there is evidence to substantiate this claim. I would appreciate any material that would help. If you could just provide the web site address or resource name, that would be fine. Thanks.

[nygreenguy]

Hi mygreenguy. I really appreciate your help. You are providing a great of information and clarifying many questions I have regarding evolution.

Greetings. No problem at all and thank you for breaking you response up!

As a result, more questions arose. You apparently believe that natural selection is not a driver but the result of what survives and what doesn’t. The bottom line is that natural selection is the explanation/mechanism (as you say) of what organisms survive to the next generation and which ones don’t. I really do not see a great difference between our definitions. We both agree that natural selection is a mechanism that determines whether a species continues in a certain environment or not. I agree that mutation and the environment determine if a change is beneficial or harmful.

Yes, I think are definitions are not all that different but I think your meaning was not precise, and as a result can lead to confusion and errors.

Every individual has variation. This variation gets passed along to their offspring. This variation can either increase or decrease future reproductive success. The result of this is natural selection. Natural selection doesnt DETERMINE which organisms survive to the next generation, rather is more of an explanation of traits and their frequency in a population. Natural selection really doesnt deal with individuals, it deals with populations, and it does so over time.

Regarding giraffes developing long necks, I agree that in the process of developing a longer neck, if the “pumps� (more precisely, sponges, valves, expanding or shrinking blood vessels, thick muscle walls, etc.) didn’t keep up with the growth of the neck, then the giraffe would somehow either stop growing a longer neck or, if its neck continued to grow longer and longer, it would most likely die as it would not be able to get blood between its heart and brain sufficiently enough for it to survive.

Correct.

I do not believe you are saying that the giraffe’s neck would grow so long and then stop growing for a generation or more and then a pump (sponge, valve, thicker muscle wall) that was needed then developed, as this is not co-evolution. I believe you are saying that as the giraffe’s neck grew longer and longer, pumps (sponges or valves) somehow developed simultaneously that controls the exact flow of blood necessary for the giraffe with the longer neck to survive. If this did not somehow happen, then the giraffes with the longer necks would have simply died out and would have become extinct.

Not exactly what I was saying. See, right now all animals has variation in traits. Even some people have longer necks than each other. Now, there is a natural limit to this variation. In an evolving giraffe, the normal variation of its neck is limited by the evolution of getting blood to the brain so by modifying the blood pumping mechanism, it allows the natural, normal neck length variance to increase. The giraffe increasing its neck length is only an expansion of its trait range and this is a result of the giraffe being able to increase its blood flow. Both of these are relative minor modifications.

I believe that we both agree that mutations occur infrequently (especially beneficial mutations) and are non-directional, that is, they could either be neutral, beneficial or detrimental (harmful) to an organism. If this is true, how could the necessary mutations, being rare and non-directional, develop pumps (sponges values, thick muscle walls) to form with the exact blood pressure regulation system necessary and to occur at precisely the right times as was needed in the development of the giraffe’s long neck as it became longer and longer? Would we say that it was just luck?

HHhmmm...infrequently? Well, it depends. Everyone has mutations, and most people have 1 new allele in a generation. Now, compared to genome size, it is small.

Now, as for the giraffe, it wasnt luck, it was selection. Those mutations which were beneficial stuck and multiplied in the population. The mutations needed are just modifications of existing traits. The giraffe has a larger heart, thicker arteries, etc... We have seen some changes like this in just a few generations of some animals. Snakes can expand and grow their organs, and even shrink them, depends on food availability.

Remember, sure we are talking about "rare" mutations, but lets use humans as an example. Our genome (n) is around 3*10^9 bases. Every replication yields around 0.3 mutations. Now, we extrapolate this to the gametes. A female egg is the result of 30 cell divisions, meaning each egg will have (.3*30= 9 mutations per egg) and each sperm (400 cell division*0.3= 120 mutations per sperm) and this means a human embryo will have 129 new mutations.

So at a population of 6 billion people, 129 mutations= 7.2 * 10^11 new mutations in the human population every generation. This is enough to replace EVERY nucleotide in our genome in LESS than a single generation.
http://sandwalk.blogspot.com/2007/07/mu ... rates.html

Now, if we look at a timeline of tens to hundreds of millions of years, there is ample time for giraffes to modify their systems.

We would agree that necessity does not cause a trait to appear in an organism, however, you stated: “its relative fitness is what drives co-evolution of the traits.� This sounds as though necessity is what causes co-evolution. Would you please clarify this?

Appearance of traits and persistence of traits are two totally different things. The appearance of traits is totally random and due simply to mutation rates. Those traits which persist are due to natural selection. "Necessity" is another way of looking at selection pressure. If you are prey to a lion and the lion gets faster, you have BETTER get faster or you become dinner. So natural selection "necessitates" the prey become faster (or some other adaptation) if the population is to survive. Chances are, some of your family and friends run at different speeds. The slower ones become dinner and the faster ones live. Those genes which allow the speed difference are what will get passed down (since the slow animals are dead). So the fastest of your kin have the highest relative fitness as they can more easily escape. So we have outside selective pressures driving evolution in a specific direction. So you can look at it as "necessity", but that would imply conscious, directional change. The only necessary thing in the above scenario is survival, speed just happens to be the trait selected.

Are you familiar with the concept of selective pressures?

You mentioned hawk moths and plant pollination illustrating co-evolution. In this scenario, the hawk moths evolved mouths that could pollinate a certain flower, as the flower evolved. Therefore, both the hawk moth and the flower benefited. I would agree that this is a good example of co-evolution. The hawk moth is a separate and totally different organism than a flowering plant. They evolved at the same time but not as one organism. I do not see how the example of the hawk moth and the flowering plant relates to a giraffe developing pumps, except that in both cases all were able to survive as a result of the changes. You mentioned: “The hawk moth, due to selective pressures, developed a mouthpart that kept up with the development of the flower.� As I mentioned previously, this sounds like necessity caused the hawk moth to develop a specific mouth shape to keep up with the development of the flower.

Not "necessity", it just did better going this route. Once again, the term necessity implies a requirement or a directionality. Many times in evolution, one population goes one way and the other evolves in a different way. The other hawk moths pollinated OTHER flowers, and it just happened to work.

I think the evolution of feathers addresses this concept of necessity better than my flower examples. The first feathers were not for flight. The first feather were simply modifications of the skin of reptiles. Feathers first served to only insulate the cold blooded animals. We see them now used for flying, but the feathers didnt evolve FOR flight. So we cant look at feathers and say "birds evolved feather for flight". That is incorrect. These original bumps and modifications of the skin just HAPPENED to help insulate the animals. As they grew, they were more efficient at insulation. So these random changes (mutations modifying traits) create a differential reproductive success (insulated dinos stay warmer and more active) which results in natural selection (we see insulators increase in frequency in the population). So there is no "necessity", rather traits which give confer differential reproductive success.

You used the analogy of the development of the giraffe’s long neck with the advances in computers. With the development of the giraffe’s long neck, you would say that it was not caused by any intelligence, that is, no designer. However, with the progression of computers, intellectual engineers caused computers to become more and more efficient.

True, but that wasnt the basis of my point. The main idea in that analogy is things in biology, just like human engineering, run into bottlenecks (no pun intended) which slow evolution and require evolution of something DIFFERENT in order to continue with overall evolution.

[Goat]

Hi Goat. Thank you for the clarification. I agree that the sex cells used for breeding (gamete) may also change during meiosis from the genes of the parents to their offspring. Hence, the offspring will not be identical to its parents. Most likely what you and Autodidact are referring to are subtle changes that over multiple generations would result in a major change. But I do not believe the immediate offspring most likely would or could result in a different species than its parents. Do you know of any occurrences where subtle changes in an offspring, eventually, through multiple generations, led to a major change in a creature, as a result of meiosis?

Not through 'meiosis', but yes, through tiny changes over successive generations has lead to major changes.

For example, Italian wall lizards developed cecal valves when isolated on an island in just a few decades

[nygreenguy]

Hi Autodidact. Thanks for your reply. I suppose from your comment that even though no major change has ever been observed in nature, there is evidence to substantiate this claim. I would appreciate any material that would help. If you could just provide the web site address or resource name, that would be fine. Thanks.

A question about this is what defines "major". What is an objective way of measuring "major"?

I always like to use the rainbow as an analogy for the magnitude of change and how evolution works. If you look at the spectra of visible light, you can see all the colors Red, Orange, Yellow, Green, Blue, Indigo, Violet. It is easy to stand back and see the differences. This is how we look at fossils. We see distinct organisms in the fossil record much like we see distinct colors.

However, if we look closer. Really, really close.


When is blue "not blue". When is red "not red". It is nearly impossible to pick a point. This is how evolution works in a human timescale. We can see the small differences, but we cant really tell if a species is still "blue" or if it is "not blue".

Genetics and fossils provide us with the information we need to be able to differentiate how species change(ed) and how they are related. The fossil record provides us with coarse scale resolution of what evolution over long periods of time look like. Modern genetics shows us the fine scale resolution of how species change AND it provides us with the "fingerprints" of coarse scale change that has happened in the past.

[Critical_Thinker]

Hi mygreenguy. I really appreciate your help. You are providing a great of information and clarifying many questions I have regarding evolution.

Greetings. No problem at all and thank you for breaking you response up!

As a result, more questions arose. You apparently believe that natural selection is not a driver but the result of what survives and what doesn’t. The bottom line is that natural selection is the explanation/mechanism (as you say) of what organisms survive to the next generation and which ones don’t. I really do not see a great difference between our definitions. We both agree that natural selection is a mechanism that determines whether a species continues in a certain environment or not. I agree that mutation and the environment determine if a change is beneficial or harmful.

Yes, I think are definitions are not all that different but I think your meaning was not precise, and as a result can lead to confusion and errors.

Every individual has variation. This variation gets passed along to their offspring. This variation can either increase or decrease future reproductive success. The result of this is natural selection. Natural selection doesnt DETERMINE which organisms survive to the next generation, rather is more of an explanation of traits and their frequency in a population. Natural selection really doesnt deal with individuals, it deals with populations, and it does so over time.

Regarding giraffes developing long necks, I agree that in the process of developing a longer neck, if the “pumps� (more precisely, sponges, valves, expanding or shrinking blood vessels, thick muscle walls, etc.) didn’t keep up with the growth of the neck, then the giraffe would somehow either stop growing a longer neck or, if its neck continued to grow longer and longer, it would most likely die as it would not be able to get blood between its heart and brain sufficiently enough for it to survive.

Correct.

I do not believe you are saying that the giraffe’s neck would grow so long and then stop growing for a generation or more and then a pump (sponge, valve, thicker muscle wall) that was needed then developed, as this is not co-evolution. I believe you are saying that as the giraffe’s neck grew longer and longer, pumps (sponges or valves) somehow developed simultaneously that controls the exact flow of blood necessary for the giraffe with the longer neck to survive. If this did not somehow happen, then the giraffes with the longer necks would have simply died out and would have become extinct.

Not exactly what I was saying. See, right now all animals has variation in traits. Even some people have longer necks than each other. Now, there is a natural limit to this variation. In an evolving giraffe, the normal variation of its neck is limited by the evolution of getting blood to the brain so by modifying the blood pumping mechanism, it allows the natural, normal neck length variance to increase. The giraffe increasing its neck length is only an expansion of its trait range and this is a result of the giraffe being able to increase its blood flow. Both of these are relative minor modifications.

I believe that we both agree that mutations occur infrequently (especially beneficial mutations) and are non-directional, that is, they could either be neutral, beneficial or detrimental (harmful) to an organism. If this is true, how could the necessary mutations, being rare and non-directional, develop pumps (sponges values, thick muscle walls) to form with the exact blood pressure regulation system necessary and to occur at precisely the right times as was needed in the development of the giraffe’s long neck as it became longer and longer? Would we say that it was just luck?

HHhmmm...infrequently? Well, it depends. Everyone has mutations, and most people have 1 new allele in a generation. Now, compared to genome size, it is small.

Now, as for the giraffe, it wasnt luck, it was selection. Those mutations which were beneficial stuck and multiplied in the population. The mutations needed are just modifications of existing traits. The giraffe has a larger heart, thicker arteries, etc... We have seen some changes like this in just a few generations of some animals. Snakes can expand and grow their organs, and even shrink them, depends on food availability.

Remember, sure we are talking about "rare" mutations, but lets use humans as an example. Our genome (n) is around 3*10^9 bases. Every replication yields around 0.3 mutations. Now, we extrapolate this to the gametes. A female egg is the result of 30 cell divisions, meaning each egg will have (.3*30= 9 mutations per egg) and each sperm (400 cell division*0.3= 120 mutations per sperm) and this means a human embryo will have 129 new mutations.

So at a population of 6 billion people, 129 mutations= 7.2 * 10^11 new mutations in the human population every generation. This is enough to replace EVERY nucleotide in our genome in LESS than a single generation.
http://sandwalk.blogspot.com/2007/07/mu ... rates.html

Now, if we look at a timeline of tens to hundreds of millions of years, there is ample time for giraffes to modify their systems.

We would agree that necessity does not cause a trait to appear in an organism, however, you stated: “its relative fitness is what drives co-evolution of the traits.� This sounds as though necessity is what causes co-evolution. Would you please clarify this?

Appearance of traits and persistence of traits are two totally different things. The appearance of traits is totally random and due simply to mutation rates. Those traits which persist are due to natural selection. "Necessity" is another way of looking at selection pressure. If you are prey to a lion and the lion gets faster, you have BETTER get faster or you become dinner. So natural selection "necessitates" the prey become faster (or some other adaptation) if the population is to survive. Chances are, some of your family and friends run at different speeds. The slower ones become dinner and the faster ones live. Those genes which allow the speed difference are what will get passed down (since the slow animals are dead). So the fastest of your kin have the highest relative fitness as they can more easily escape. So we have outside selective pressures driving evolution in a specific direction. So you can look at it as "necessity", but that would imply conscious, directional change. The only necessary thing in the above scenario is survival, speed just happens to be the trait selected.

Are you familiar with the concept of selective pressures?

You mentioned hawk moths and plant pollination illustrating co-evolution. In this scenario, the hawk moths evolved mouths that could pollinate a certain flower, as the flower evolved. Therefore, both the hawk moth and the flower benefited. I would agree that this is a good example of co-evolution. The hawk moth is a separate and totally different organism than a flowering plant. They evolved at the same time but not as one organism. I do not see how the example of the hawk moth and the flowering plant relates to a giraffe developing pumps, except that in both cases all were able to survive as a result of the changes. You mentioned: “The hawk moth, due to selective pressures, developed a mouthpart that kept up with the development of the flower.� As I mentioned previously, this sounds like necessity caused the hawk moth to develop a specific mouth shape to keep up with the development of the flower.

Not "necessity", it just did better going this route. Once again, the term necessity implies a requirement or a directionality. Many times in evolution, one population goes one way and the other evolves in a different way. The other hawk moths pollinated OTHER flowers, and it just happened to work.

I think the evolution of feathers addresses this concept of necessity better than my flower examples. The first feathers were not for flight. The first feather were simply modifications of the skin of reptiles. Feathers first served to only insulate the cold blooded animals. We see them now used for flying, but the feathers didnt evolve FOR flight. So we cant look at feathers and say "birds evolved feather for flight". That is incorrect. These original bumps and modifications of the skin just HAPPENED to help insulate the animals. As they grew, they were more efficient at insulation. So these random changes (mutations modifying traits) create a differential reproductive success (insulated dinos stay warmer and more active) which results in natural selection (we see insulators increase in frequency in the population). So there is no "necessity", rather traits which give confer differential reproductive success.

You used the analogy of the development of the giraffe’s long neck with the advances in computers. With the development of the giraffe’s long neck, you would say that it was not caused by any intelligence, that is, no designer. However, with the progression of computers, intellectual engineers caused computers to become more and more efficient.

True, but that wasnt the basis of my point. The main idea in that analogy is things in biology, just like human engineering, run into bottlenecks (no pun intended) which slow evolution and require evolution of something DIFFERENT in order to continue with overall evolution.

vvvvvvvvvvvvvvvvvvv
Hi nygreenguy. That you for your reply. Regarding your comment “The giraffe increasing its neck length is only an expansion of its trait range and this is a result of the giraffe being able to increase its blood flow. Both of these are relative minor modifications.�

You appear to be saying that it was a simple matter for the giraffe to have expanded its trait range to allow the giraffe to be able to increase its blood flow, but in the natural world, how could this have happened?

Actually, not only did the increased neck length require increased blood flow, it also needed a mechanism to decrease the blood flow when the giraffe bends its head down when it wants to pick up something from the ground. If the blood continued to flow at the same rate as it does when the head is held high, then most likely the giraffe’s brain would receive an excessive amount of blood and might suffer from a brain hemorrhage.

It is my understanding that the giraffe’s neck is made in such a manner to accommodate both sudden moves of the head either up or down. I believe that it would have been a major problem that needed to be overcome. It may seem simple after the fact, but I believe it was a major problem while the giraffe’s neck was in the process of getting longer and longer.
---
You also mentioned: “I think the evolution of feathers addresses this concept of necessity better than my flower examples. The first feathers were not for flight. The first feather were simply modifications of the skin of reptiles. Feathers first served to only insulate the cold blooded animals. We see them now used for flying, but the feathers didnt evolve FOR flight. So we cant look at feathers and say "birds evolved feather for flight". That is incorrect. These original bumps and modifications of the skin just HAPPENED to help insulate the animals. As they grew, they were more efficient at insulation. So these random changes (mutations modifying traits) create a differential reproductive success (insulated dinos stay warmer and more active) which results in natural selection (we see insulators increase in frequency in the population). So there is no "necessity", rather traits which give confer differential reproductive success.�
^^^
I studied what would need to occur for a reptile with scales to develop feathers and it does not seem to me to be something that could easily have happened. I believe that it has been determined that birds evolved from saurischian (lizard-hipped dinosaurs [reptiles]), possibly the compsognathus. I am sure you are aware of the many obstacles that would have needed to be overcome for this to occur.

If the compsognathus (dinosaur reptile) gradually changed from a cold-blooded animal to a warm-blooded creature, it may have needed to retain its body heat to survive. If feathers developed to accomplish this, it must have occurred at the exact right time, as it may have been critical for the reptile’s survival. But we would agree that necessity is not what caused feathers to form on this reptile. If this occurred naturally, the timing and appearance was simply amazing.

For reptile scales to develop bird feathers would have been an incredible feat to occur naturally. It may have been possible that feathers originally developed on reptiles that were used to keep them warm and were later used for flight as the reptile evolved more and more into a bird. We would both agree that feathers did not develop for the specific need to keep reptiles warm. It just occurred and proved to be beneficial, if not necessary, for its survival.

I read that feathers have been described as horny outgrowth of skin peculiar to the bird but similar in structure and origin to the scales of fish and reptiles. Most evolutionists would agree that feathers gradually developed from a loose, hanging, frayed scale. I suppose these loose hanging scales would only have been used for warmth, not flight. This would mean that these evolving reptiles would not have been able to fly until after the feather had been perfected with the barbicels with the tiny hooks.

Some who object or question this scenario state: “Feathers grow individually from tube-like follicles similar to hair follicles. Reptilian scales, on the other hand, are not individual follicular structures but rather comprise a continuous sheet on the surface of the body. Thus, while feathers grow and are shed individually (actually in symmetrically matched pairs), scales grow and are shed as an entire sheet of skin. The feather is made up of hundreds of barbs, each bearing hundreds of barbules interlocked with tiny hinged hooklets.� Would you agree with this description?

I also read the following description of feathers: “each parallel barb, slanting diagonally from the shaft, is not hair like, but appears as a miniature replica of the feather itself, with numerous smaller side branches, or barbules, that overlap those of the neighboring barbs in adhering to one pattern. They have tiny projections called barbicels, many of which are equipped with minute hooks that neatly hold everything in place. The single pigeon feather may have several hundred thousand barbules and millions of barbicels and hooklets.�

The feather is further described as: “The central shaft of a feather has a series of barbs projecting from each side at right angles. Rows of smaller barbules in turn protrude from both sides of the barbs. Tiny hooks, called barbicels, project downward from one side of the barbules and interlock with ridges on the opposite side of adjacent barbules. In some feathers there may be as many as a million barbules cooperating to bind the barbs into a complete feather, resistant to air penetration. In addition, the positioning of the feathers is controlled by a complex network of tendons that allow them to open like the slats of a blind when the wing is raised. As a result, wind resistance is greatly reduced on the upstroke. On the down stroke, the feathers close, providing resistance for efficient flight.�

To date, I have not read of any dinosaur fossils that have been discovered that illustrates the progression of reptile scales to bird feathers, although I realize this is debatable. The Microraptor gui discovered in China is said to have had feathers or feather-like projections. “Sinornithosaurus millenii,� also discovered in China, may also have had feathers or something like feathers. Actually, what appears to be projecting from these dinosaurs are not feathers as we would describe feathers. The so-called feathers on these dinosaur fossils are described as “having been covered with a coat of down-like fibers or early proto-feathers, as they are called (but not actual developed feathers).�

A more detailed description of Sinornithosaurus is as follows: “Sinornithosaurus clearly shows impressions of filamentous feathers, especially on the head and forelimbs. Its whole body was covered with long, thin feathers that were so small that they couldn’t have helped it fly. Sinornithosaurus showed two features that indicate it had early feathers. First, several filaments were joined together into “tufts�, like the structure of down feather. Second, a row of filaments (barbs) were joined together to a main shaft (rachis), making them similar in structure to those of normal bird feathers. However, they do not have the secondary branching and tiny little hooks (barbules) that modern feathers have, that allow the feathers of modern birds to form a distinct vane. The feathers covered the entire body in fossil NGMC—91, including the head in front of the eye, the neck, wing-like sprays on the arms, long feathers on the thighs, and a elongated-shaped fan on the tail.�

The question is, were the filamentous feathers, long, thin feathers-feathers, early proto-feathers, really feathers, or were they long hairs? A filament is defined as “A fibril, fine fiber, or threadlike structure.� This definition does not appear to describe feathers in the making, or something in the process of developing into a feather, but appears more like hairs. It is difficult to determine exactly what the covering was by merely examining a fossil.

Sinosauropteryx is not considered a bird or bird-like, as it has no structures that even resemble feathers. The proto-feathers that are described for Sinosauropteryx and similar fossils are filamentous, interlaced structures, often referred to as dino-fuzz. I read that scientists now believe that these are actually connective tissue fibers (collagen) found in the deep dermal layer of the skin rather than feathers in the making.

I read an article from someone who questions that this dinosaur had proto-feathers. The article stated in part: “The so-called proto-feathers (or dinofuzz) that were found imprinted in the Sinornithosaurus fossil cannot be considered filaments, but are only fossilized impressions of filaments. This makes it virtually impossible to obtain an accurate analysis of what the impressions really are. It has been noted that the wispy hair-like structures are so different than modern bird feathers that it is doubtful that the filaments could even be related to feathers at all.�

If this analysis is accurate, then it is doubtful that any convincing evidence currently exists to justify that dinosaur reptiles evolved into birds, at least not reptile scales to bird feathers. Do you know of any of fossil evidence that could indicate that reptilian scales evolved into bird feathers?

I have read those who doubt that a reptile evolved into a bird question what use a mutated hand would have to a creature while it is in the process of evolving into a wing. Most likely, if the mutated hand were in fact useless or even detrimental, the creature would not have been able to continue.

If the wing evolved, it would have had to develop through many ‘small’ mutations in a specific order and timing, assuming that a reptile with arms or legs evolved into a bird. The difficulty would be that these small mutations are not as small as they might appear. Even with billions of years of random mutational change, the probability of these small, neutral mutations remaining, is minimal. As the same type of creature continues to produce offspring, the new small mutations would not be dominant, and would therefore not appear in every new offspring, which in turn may gradually be eliminated altogether as the species evolves. Even if a new organ all of a sudden appeared in a creature, if it were not proven to be beneficial, it would be a disadvantage to the creature and would subsequently lead to its elimination by natural selection.

There are also other features that are different between a reptile and a bird. As previously mentioned, reptiles are cold-blooded while birds are warm-blooded. Reptile lungs are different than bird lungs. The lungs of reptiles consist of millions of tiny air sacs; whereas, bird’s lungs have tubes. Most reptiles have a three-chambered heart while birds have a four-chambered heart, as most mammals do. For these changes to have developed naturally, it appears that many small, minute, possibly life threatening, changes would have needed to have occurred for a reptile to have evolved into a bird, even if these changes occurred over millions of years. I have not read a good explanation of how these changes could have occurred. Do you know of any explanations of how these changes might have taken place?

End

[nygreenguy]

vvvvvvvvvvvvvvvvvvv
Hi nygreenguy. That you for your reply. Regarding your comment “The giraffe increasing its neck length is only an expansion of its trait range and this is a result of the giraffe being able to increase its blood flow. Both of these are relative minor modifications.�

You appear to be saying that it was a simple matter for the giraffe to have expanded its trait range to allow the giraffe to be able to increase its blood flow, but in the natural world, how could this have happened?

Actually, not only did the increased neck length require increased blood flow, it also needed a mechanism to decrease the blood flow when the giraffe bends its head down when it wants to pick up something from the ground. If the blood continued to flow at the same rate as it does when the head is held high, then most likely the giraffe’s brain would receive an excessive amount of blood and might suffer from a brain hemorrhage.

It is my understanding that the giraffe’s neck is made in such a manner to accommodate both sudden moves of the head either up or down. I believe that it would have been a major problem that needed to be overcome. It may seem simple after the fact, but I believe it was a major problem while the giraffe’s neck was in the process of getting longer and longer.
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See Darwin himself answered this question long ago.

Darwin answered this claim in 1868 (206). The claim assumes that "gradually" must mean "one at a time." Not so. The different features could have (and almost certainly would have) evolved both simultaneously and gradually. Partial valves would have been useful for reducing blood pressure to a degree. An intermediate heart would have produced enough pressure for a shorter neck. A smaller net of blood vessels in the head could have handled the lesser pressure. As longer necks were selected for, all of the other components would have been modified bit by bit as well. In other words, for each inch that the neck grew, the giraffe's physiology would have evolved to support such growth before the next inch of neck growth.

From talkorigins.org

The mechanisms for blood flow in a giraffe are valves (common), the rete mirabile are in all even toed ungulates, and increasing the size of the hear is also not a difficult task. The rete mirabile cluster of arteries and veins controls the pressure as the head goes down and the valves control blood when the head goes up.

I explained your complaints about this several times. It was co-evolution. We didnt have an explosion of one trait and then later another. These things developed gradually, together.

If this analysis is accurate, then it is doubtful that any convincing evidence currently exists to justify that dinosaur reptiles evolved into birds, at least not reptile scales to bird feathers. Do you know of any of fossil evidence that could indicate that reptilian scales evolved into bird feathers?

http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwz ... 347399.pdf
(watch all 5)
http://icb.oxfordjournals.org/content/40/4/687.full
http://ngm.nationalgeographic.com/2011/ ... immer-text

I have read those who doubt that a reptile evolved into a bird question what use a mutated hand would have to a creature while it is in the process of evolving into a wing. Most likely, if the mutated hand were in fact useless or even detrimental, the creature would not have been able to continue.

Argument to incredulity. Simply because you do not understand the mechanism, does not mean it didnt/couldnt happen.

If the wing evolved, it would have had to develop through many ‘small’ mutations in a specific order and timing, assuming that a reptile with arms or legs evolved into a bird. The difficulty would be that these small mutations are not as small as they might appear. Even with billions of years of random mutational change, the probability of these small, neutral mutations remaining, is minimal.

Evidence for this claim?

As the same type of creature continues to produce offspring, the new small mutations would not be dominant, and would therefore not appear in every new offspring, which in turn may gradually be eliminated altogether as the species evolves. Even if a new organ all of a sudden appeared in a creature, if it were not proven to be beneficial, it would be a disadvantage to the creature and would subsequently lead to its elimination by natural selection.

Ok, you got the trait ELIMINATION part of natural selection down, but what about the part where it KEEPS traits?

There are also other features that are different between a reptile and a bird. As previously mentioned, reptiles are cold-blooded while birds are warm-blooded. Reptile lungs are different than bird lungs. The lungs of reptiles consist of millions of tiny air sacs; whereas, bird’s lungs have tubes. Most reptiles have a three-chambered heart while birds have a four-chambered heart, as most mammals do.

Well, lets start with some interesting similarities between birds and reptiles:
1) Skulls hings on a single condyle
2)Lower jaw is made of several bones
3)Single middle ear bone
4)Pneumatic bones
5)Scales on legs
6)Lack of skin glands
7)Egg laying
8)Nucleated red blood cells
9)Ankle joint is intertarsal (bends foreward)
10)Uncinate process - overlapping tabs in the ribs
11) embryonic development similarities

Also, I never said feathers evolved from scales. I said they were modified from the skin (epidermal modifications). THIS JUST MEANS THEY ARE SKIN ORGANS THAT FORM BY CONTROLLED PROLIFERATION OF CELLS IN THE EPIDERMIS OR OUTER SKIN LAYER, THAT PRODUCES THE KERATIN PROTEINS THAT FORM FEATHERS.
(sorry, caps lock)


So I listed similarities and you listed differences. Now, what can explain BOTH?

Well, if we look at the fossil record we see an increase in the assymetry of the feathers (leading to flight feathers), a decrease in tail size, increased size of the pectoral girdle and keel, decreased teeth, and the list goes on and on. We see an obvious transition of all the things that make birds different from dinosaurs in the fossil records, although many argue that birds really are just "glorified" dinosaurs.

For these changes to have developed naturally, it appears that many small, minute, possibly life threatening, changes would have needed to have occurred for a reptile to have evolved into a bird, even if these changes occurred over millions of years. I have not read a good explanation of how these changes could have occurred. Do you know of any explanations of how these changes might have taken place?

End

Look in the primary literature.

[Dokimas]

Yes, I have seen the imagined superimposed "limits" on micro-evolution; however these limits have never been identified or even shown to exist. Until they can do that, my analogy holds.

I'm jumping in without reading anything that follows, so forgive me it you have answered me or someone else has brought up my ideas.

First, could you show real evidence of life arising out of non-life? If you can't I'm not sure you have a solid position.

Second, your analogy starts with something that can't happen and you're trying to convince us it 'proves' something that you say does/did happen? Again, you position doesn't seem too solid to me.

[Dokimas]

Imagine that you can travel across the universe by walking. You have an infinite amount of time to do this, but you must make your journey by taking small steps. You have no destination, but you can go anywhere and you must never stop walking.

A thousand years pass. Where are you now? Further.
A million years pass. Where are you now? Even Further.
A billion years pass. Where are you now? Far, far away.

For every iteration of time, you will have traveled further and further. It is inevitable, for every small step takes you further. It is not possible to not travel far.

It's even more than that when you consider that changes compound over time. For example, let's say that there is an animal that is increasing in size one percent every thousand years. The average weight of the animal is one pound.

A thousand years pass. The average weight is 1.01 pounds.
70,000 years pass. The average weight is 2 pounds.
A million years pass. The average weight is 20,959 pounds.
2 million years pass. The average weight is 439,286,205 pounds.
A billion years pass. The average weight is absolutely ridiculous.

Yet, if you were a biologist studying this animal over the course of your lifetime and measuring change in average weight over time with high precision you would not notice any change at all.

If I did this observation, I think you'd have the right to call me a spaghetti monster.

[Dokimas]

Piffle. Your analogy holds only if you can show that it holds, and you have not done so. You have offered precisely zero supporting evidence that the key point of your analogy -- that genetic change can accumulate indefinitely -- is correct. All you have done is restate your original claim in analogical form

I said "My analogy holds because creationists claim there to be a limit where there is none". That's the evidence. If you know what the limits are, what are they? Go on, tell us. We're eager to hear the information you've got that will revolutionize biology.

And the analogy you have chosen isn't even rhetorically useful, since in reality one cannot walk across the universe.) Since you made the assertion, you need to provide the evidence.

The analogy was about iterative processes, like walking. It doesn't matter if it can't really happen, because that wasn't the point. Besides, you're making the assertion that evolution will stop at some arbitrary point - I'm asking you what that point is.

First, it is not true that macroevolution is identical to microevolution. At a minimum, macroevolution includes the process of speciation while microeviolution does not.

My point was that micro-evolution over large periods of time will necessarily lead to macro-evolution. "Macro-evolution" is simply the collective of small iterative changes that might lead to these things - I'm telling you they are not separate processes. It is the "whole" as opposed to the "part", like a grain of sand is a part of an entire coastline.

In your analogy, if the person is walking in a circle, she/he won't get out into the universe. If micro-evolution is like walking in a circle, it is it's own limit.

IMO, you still have a huge problem to deal with: how did life start? Of course, there's tons of questions that follow.

[Goat]

Yes, I have seen the imagined superimposed "limits" on micro-evolution; however these limits have never been identified or even shown to exist. Until they can do that, my analogy holds.

I'm jumping in without reading anything that follows, so forgive me it you have answered me or someone else has brought up my ideas.

First, could you show real evidence of life arising out of non-life? If you can't I'm not sure you have a solid position.

Second, your analogy starts with something that can't happen and you're trying to convince us it 'proves' something that you say does/did happen? Again, you position doesn't seem too solid to me.

And what does abiogensis have to do with the TOE? This is a very big red herring, because the TOE does not address the origin of life. It merely is a model that explains the observation of how life changes over time.

It sort of an analogy of 'plumbing is not useful if the plumber can not explain the origin of the water'...