Fine tuning/ programming

The following link explains in greater detail what jacortina has said. The basic idea is that the simplest heart in the simplest organisms (invertebrates) would have been a muscular tube that rhythmically contracted and it was simple because all it was required to do was pump nutrients throughout the entire body.As the invertebrates evolved to vertebrates, the fish heart would have been the next stage in the evolution of the mammalian heart. If you click on "fish," the diagram will show how the fish is heart still tube-like but with obvious sections of the tube. It is a two-chambered heart, still a single-circuit system. All that should be required for such an advance is the mutation of a single gene (probably) that separates the signal sent to the nerves that control the rhythmic contractions of the single muscular tube from one to two.As fish begin to flop onto land, possibly to escape sea predators, becoming amphibians, the amphibian heart develops into a three-chambered heart. It is now multi-circuit with two atria and a single ventricle. The oxygenated and deoxygenated blood are somewhat separated by the different timings of the the right and left atria. First one pumps, then another. Again, only an order of several mutations over millions (maybe hundreds of millions) of years is needed to separate the atrium into 2 atria, time the contractions, and have deoxygenated blood go in one atrium and oxygenated blood go in the other.As amphibians begin advancing futher and further away from water, they eventually become reptiles. The reptilian heart evolves to become a hybrid amphibian/mammalian heart. Again, the diagram for reptiles shows the same amphibian heart with a few changes that have evolved. First, the ventricle is partially divided. Second, the conus is also divided. This is true for most reptiles with one notable exception, the crocodile. The crocodile evolved a four chambered heart similar to birds and mammals except for slight differences that allow the crocodile to switch between normal and low oxygen conditions. Once again, these are minor changes that have occurred over the course of hundreds of millions of years.Finally, from reptiles we finally come to the birds and mammals. The splitting of the ventricle is complete, the atria are divided and we have the four chambered heart. The process from an invertebrate heart to a mammalian one is one that requires very little changes over time. Since a single mutation can have a large impact on the development of an organism, the change from invertebrate heart to mammalian heart needs perhaps a handful of mutations. Given that evolution occurs over the course of the history of life (which is dated to about 3.5 billion years) regardless of how life started, there would seem to be enough time for the mammalian heart to have developed. Simply because time and a few mutations can have a great effect of the development of a species. Even though our knowledge of genetics is incomplete, we know that a change in a single gene in human DNA can affect the development of a person. Think about all the number of genetic disease that occur from the mutation of a single gene. According to Wiki, there are estimated to be over 4000 single gene disorders. You, being a doctor, probably have resources that are better able to verify this.This is why I don't believe that the mechanism was designed by someone. This is why I accept evolution as a credible theory.*Disclaimer: My simplistic explanation using fish, amphibian, reptile by no measure means that I am suggesting that modern mammals evolved from modern reptiles, reptiles are descended from modern amphibians, and so on down the line. My explanation is to simplify the process and what I am actually referring to are the common ancestors that each group shared with the other groups.Also, for additional reading, in September of this year, a genetic link was found between reptilian and mammalian hearts. Check it out here.Edited by Izanagi, : No reason given.Edited by Izanagi, : No reason given.Edited by Izanagi, : No reason given.

The development of an organism relies on genes in order to determine when and what amino acids are produced. Change the sequence of one gene and you potential affect the growth of an organism. The thing is, making changes to an organism doesn't require much tinkering with the genome. For instance, sickle cell anemia is the effect of a single mutation that causes the red blood cell to form into a "sickle" shape. Just a single mutation affects the production of hemoglobin which then affects the shape and function of the red blood cell. So it wouldn't be far from thinking that a single mutation could cause two nerves to fire in sequence rather than in conjunction because that is all that is required to have the different heart chambers beat in sequence. It's not a complicated design but a simple mutation - just have two nerves fire in sequence rather than in conjunction. Every time a creationist talks about mutations working towards a common goal, an angel cries in Heaven.No matter how anyone will anthropomorphize evolution or mutations, evolution is a process and mutations are one part of the process. Evolution and mutation are processes in the same way that gravity is a process; you would never say that gravity's "goal" is to keep you down, would you?Mutations just occur. How an organism evolves depends on the selective pressures of the environment. For instance, a two Big Horn Sheep rams are born, one that acquired a mutation for a thinner skull and that acquired a mutation for a thicker skull. The mutations themselves are neutral until an external force, i.e. the environment, acts upon them. Prior to mating season, rams butt heads to determine the mating hierarchy. Because of the butting heads, the environment has now acted upon the rams and the selective pressure here is for rams with thicker skulls. Thus we can expect our thicker skull ram to do better than our thinner skull ram, allowing the thicker skull ram to have access to more ewes consequently spreading his mutation throughout the Big Horn Sheep population through his progeny while the thinner skull ram may only be able to mate with one ewe. The ram with the thicker skull is more fit due to selective pressures than the ram with the thinner skull.Selective pressures determine which mutations, if any, allow an organism better fitness to survive. But there is no common goal being worked towards. Mutations aren't usually bad nor good. We perceive of mutations as being bad because the visible effects that we do see of mutations are bad. But there are many millions of mutations to which we do not see any visible effect whatsoever. For instance, we wouldn't see a mutation that allows a person to metabolize food faster, nor a mutation that makes a person more agile, or a mutation that decreases reflex speed, or the mutation that doesn't do anything at all. The truth is mutations often do not have any visible signs, so forget about the X-Men. What you'll find instead is that most mutations will occur and propagate with no visible signs or any ill effects.So to say that mutations are generally bad is to ignore the fact that thousands of mutations have and will occur that have had no visible effect on an organism, including humans.

There are elements that can cause a mutation to happen. Errors in DNA replication, radiation, chemicals, viruses, etc. All these can cause a mutation to occur, but where the mutation occurs in the DNA is completely random.Edited by Izanagi, : No reason given.

Ah, my mistake. Thank you for pointing it out.I should have said that where the mutations occur is random, although some places have a greater likelihood of mutating than others.

I have to say, I was a bit daunted by your post. But after slogging through cardiac action potential and its various phases, the potassium channels, arrhythmia, calcium channels, etc., I think I have a handle on your question. It may not be as detailed as you may like, but I'll try my best. Forgive my ignorance. It's been awhile since I've read up on the heart. Action potential is the passage of ions through the cell membrane. Although the membrane is semi-permeable, the cell membrane prevents the diffusion of polar solutes across the membrane. This gives the cell the control of movement through the membrane through the pores and gates. Now the ion channels are essentially proteins formed into pores that can control the passage of the small voltage gradient. Wouldn't it be logical to think that a small mutation would have changed some of the pores that allowed some substance to pass through a transmembrane protein into a pore that allowed ions to pass through? And assuming that it provided an evolutionary advantage, it wouldn't be illogical to think that cells would begin to carry this mutation over time.Whatever the original evolutionary advantage was for action potential, there is an added advantage as it relates to communication between cells. Consider that the first single-celled organisms that grouped together needed a way to communicate, action potential offered a ready option. Communication by action potential is quick, about 1/3 the speed of sound, compared to using alternative methods. For multi-cellular organisms, the evolutionary advantage of action potential in intercellular communication is too great to ignore, which is why nearly all multi-cellular organisms use action potential as a means of communication between cells. First, skeletal and cardiac muscles are very similar with regards to striations and contractions. The primary structural proteins of both skeletal and cardiac muscles are actin and myosin. The difference is that cardiac muscles may be branched rather than linear and longitudinal. Like skeletal muscles, cardiac muscles initiate action potential through the entry of sodium ions across the sarcolemma. Cardiac muscles, however require extracellular calcium ions for contraction to occur. The point is that skeletal muscle and cardiac muscle are similar and cardiac muscle can be seen as the intermediate between skeletal muscle and smooth muscle. In fact, it may be that cardiac muscles are the next evolutionary step between skeletal and smooth muscle but that's just my own thoughts there. Do you mean "leaky" potassium channels? You never mentioned "leaky" sodium channels.I'm sorry, I don't see how "leaky" potassium channels create the heart's rhythm. The rhythm of the heart (here, I'm assuming you mean heartbeat) is set by the pacemaker cells which are typically the cells that undergo depolarization the fastest, right? Those cells are typically found in the SA Node, right? This is what you might find if you conjecture that cardiac muscles evolved from smooth muscle. Smooth muscles do not rely on action potential for contraction. Because smooth muscles are ill-suited to work as a heart, there is an evolutionary advantage in a mutation that changes smooth muscle into cardiac muscle as smooth muscles contract slowly and may hold the contraction for prolonged periods. More constant, consistent pumping means nutrients are consistently flowing which allows for sustained physical activity. Cardiac muscles evolving into skeletal muscle would be the next step as endoskeletons began to form. Again, this takes advantage of the fact that action potential is the fastest way for cells to communicate with each other. Compare that with releasing hormones to begin contractions, there is an evolutionary advantage in mutations that allow cardiac muscles to utilize action potential better than it was previously. You are essentially saying that God made the heart the way it is to prevent tetanus but I could just as simply ask: why didn't God not create the bacteria that causes tetanus in the first place?You are also making a logical fallacy by saying correlation implies causation. Just because tetanus is likely prevented by the way our hearts are constructed does not mean that was the reason for why our hearts are the way it is. The fact that the way the heart is might prevent tetanus would just an additional evolutionary advantage, but the more significant advantages are that our hearts allow for sustained activity, more rapid movement, a larger size, and better nutrient transport. Evolution, in fact, accounts for the development of the heart since any mutation of the heart that confers advantages for an organism that other organisms in a population would not have would make that particular organism better fit than the rest and likely more reproductively successful. Thus we have those advantages simply because the mutations created organisms that survived better in their environment. I conjecture that smooth muscle gave rise to cardiac muscle. Consider that modern invertebrates utilize smooth muscle, and considering it is the simplest of all muscle groups, it's likely that the earliest invertebrates also utilized smooth muscle. Mutations that gradually changed smooth muscle into cardiac muscles would give certain invertebrates an evolutionary advantage as they could achieve greater size and sustain longer durations of movement as well as more rapid movement. Nature cannot program itself, but that doesn't mean that there is no underlying order to it. Don't confuse apparent chaos to actual chaos; that's a big problem with many creationists. The Theory of Evolution states the underlying order are the mutations that give rise to variations and the environment which determines which variations are of a stronger fitness, weaker fitness, or of a neutral fitness. That means that while there is no plan, there is a method to the madness. It's similar to the weather systems. At first glance, it may seem like chaos but humanity can predict the weather with relative accuracy (weatherman jokes aside) because we perceive the underlying order beneath the apparent chaos. We understand how the water cycle, ocean temperatures, prevailing wind currents, etc all affect the weather. Evolution is similar in that it explains the underlying order beneath the apparent chaos. Yet the weather systems are intricate and complex. Did they happen without a creator? Is God out there right now controlling the weather?Intricate and complex systems can arise out of the interaction of rather simplistic parts. We understand gravity and its effect on mass and force. We understand and inertia and the conservation of momentum. Yet if a strong wind pushes a teetering rock down a mountain, we can't predict which rocks will be dislodged or how each and every rock will fall in a rockslide. A rockslide is an intricate and complex system that arises because of simplistic parts. Mutations in the genome aren't inherently positive or negative. It's the environment that determines which mutation is of greatest benefit to an organism. Mutations can create the different parts of a heart, but it is the environment the organism with the mutations is in that determines if the mutation is beneficial to the survival and fitness of the organism. Anthropomorphism may be how the majority of humans understand and explain inanimate/non-living entities, but it has no place in science. Astrophysicists do not attribute intelligence or emotions to Jupiter. Astrophysicists are not saying that Jupiter is where it is because it wants to be there. They describe the forces involved and how they interact to produce a model which describes the orbit of Jupiter. No anthropomophisizing involved. And if anthropomorphism is the ontological basis for the existence of God, then I can see why scientists reject that argument. After all, if I can conceive of a Flying Spaghetti Monster, and I can, does that mean he exists?As I've written a lot, I'll just conclude here. The parts that you addressed in your post about the heart can be explained by evolution. Ion channels could have easily mutated from channels that processed other materials. While I couldn't tell you the evolutionary advantage for a single celled organism (I could think about it, I suppose), I can tell you that action potential does confer a great advantage for multi-cellular organisms for inter-cellular communication. Mutations in smooth muscles to create cardiac muscles would increase the fitness of an organism as would an adaptation to take advantage of action potential in producing heart rhythms. As you can see, with each successive mutation, the heart has grown more and more complex. This shoots down the idea that complexity and intricacy require an intelligence. All that is required are small changes that produce an advantage in the environment. The Theory of Evolution, in a nutshell, has no difficulty addressing the evolution of the heart.

This isn't an assumption; there had to have been a protein channel simply because a cell would have no other way of receiving nutrients otherwise. Remember, I said that the cell membrane is only semi-permeable, meaning that it only allows certain molecules to diffuse across the membrane while other molecules are prevented by the structure of the membrane. Those molecules that are can't diffuse across the membrane include amino acids, carbohydrates, proteins, and ions. If there were no pores or gates to allow those molecules into and out of the cell through the membrane, how would the cell receive nutrients and remove waste? I don't know for certain how many mutations are required to change a channel into an ion channel as I am not a geneticist. But I know how many genetic mutations are required for Long QT syndrome to arise. One. And that's a single mutation that affects the repolarization of the heart. If a single genetic mutation can change such a complex system as the human heart, then why can't a single mutation change a simpler system like changing a channel for proteins into one for ions? You're making the assumption that the first cells couldn't survive without the structure we associate with cells today. Bear in mind that the environment 3.5 billion years ago was dramatically different than it is now. It's conceivable that the protocells could survive in that environment but developed structures that improved upon their survivability. So the fact that you assume the early cells could not survive without those structures in place now bears no relation to what is actually true of the first protocells. Since we have no fossils of the earliest lifeforms, I will, instead, look at the earliest cells that are similar to the cells of today. With the cell membrane already in place, the only explanation you would need for the mutation of ion channels to spread throughout a single-cellular population is an evolutionary advantage, which you yourself provided - that ion exchange allows for the ability to maintain pH and osmotic pressure. Action potential may not be an evolutionary advantage for single-celled organisms, but ion exchange is, as you have mentioned. The leap from ion exchange to action potential is extremely {small}*, and one can imagine that a multi-celled organism with rapid communication between cells has an evolutionary advantage over a multi-celled organism with slower communication between cells. Since action potential is dependent upon ion exchange, and since ion exchange would already be present in single-celled organism due to its evolutionary advantages, a mutation or two could give cells the ability to communicate through action potential. But you're assuming that, under evolution, changes to a previous patterns would create totally new patterns. In fact, evolutionary theory would suggest that parts that have similar function would be similar in structure, even across organisms. This is due to incremental changes to the existing structures. Similarity does imply an evolutionary relationship. As changes accumulate, the original structure isn't lost, but rather built upon. So, in fact, evolutionary theory does explain the similarities of smooth, cardiac, and skeletal muscle.Furthermore, it doesn't matter what the functions of skeletal, cardiac, and smooth muscles are, but how they operate and they all operate in similar fashion; that is, they all contract. The fact that all the muscles are similar in structure and operation is evidence for evolution. Under evolution, new functions are taken up by existing structures that are eventually improved upon to increase their efficacy in that new function. So, in fact, we would expect to see structural and operational similarities in different parts, which we do.So my question to you is this: What rationale do you present to support your argument that an intelligent designer would use structurally and operationally similar parts for different functions? Wouldn't an intelligent designer have used structurally and operationally different parts for different functions? Your way seems to be a case for a lazy designer. I read your link. Let me quote something from that page:

quote:

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SA node = has the highest or fastest rhythm &, therefore, sets the pace or rate of contraction for the entire heart. As a result, the SA node is commonly referred to as the PACEMAKER.

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So I'm not sure why you sent me to that link. Your own link proved my point that the SA Node sets the heart's rhythm because it has the highest and fastest rhythm and is therefore called the pacemaker. So thank you for proving my point. The same way a single fertilized egg becomes a fetus. The genes code for certain amino acids which are combined to create proteins which are then used for various functions. A mutation in the genes for building the heart could have allowed for the use of troponin in the structure of the heart. That addition would have granted the resulting organism better fitness and likely better chances at reproduction, allowing that particular mutation to spread throughout the population.Remember, nothing "evolves" chemicals. What we do is mutate to produce different chemicals than what was originally supposed to be used. And we see that mutations do have an effect on how the body produces chemicals that the body uses. So a mutation could have caused a developing embryo to produce troponin and utilize it rather than something else. Apologies. I should have said that smooth muscle is the earliest form as it is present in invertebrates. I'm sorry, but you are trying to apply meaning beyond what we can see. And in fact, your example is false because we are the ones who applied meaning to those dots. Throw the same dice in front of someone who doesn't know what dice are, and it would be meaningless to them. To them, it's nonsense.Now, if you were to see the aftermath of a hurricane, would you assume an intelligence behind that destruction, or would you say it was a natural disaster? What meaning would you attach to that event?The fact that complex systems have any meaning at all is because WE attach significance to those systems. And that's what you have done - you have attached more meaning to a complex system than what is there. But whether or not we attach significance to those systems doesn't matter to the fact that complex systems are a result of interactions between simpler systems. Whether we are here or not to attach significance to those complex processes, the earth will still go around the sun, the sun will still go around the milky way center, etc. Anyone with more than two neurons in their brain would know know that, when talking science, you should never attach more significance than is already there. Prove to me that there has been no evidence for the existence of the FSM and that there is evidence for the existence of your deity. If this debate has now dissolved into ontology and you are going to stop arguing scientifically, then I can, and will, argue that the FSM is responsible for the complexity of the heart. In fact, everything complex thing you see is a direct result of the goodness of the FSM and his desire to work for our benefits. All the bad things you see are a result of people's denial in the goodness of the FSM and their unconscious desire to rebel against him. Henderson was the prophet of the FSM and the desire of the FSM to reveal himself to the world. Now, prove me wrong, logically.If you cannot prove me wrong logically, then I would suggest that we not delve into ontological arguments and just debate the science. And with this statement, I can see that your understanding of science is less than minimal. Let me ask you this, do you think the Germ Theory of disease is just a "theory?" Is the Theory of Gravity just a "theory?"Environment pushes the drive for improvements forward; and new improvements pushes the environment to compete. It's a constant race with one pulling the other and that's what evolution is - the results of that race. There are no assumptions in evolutionary theory has that can match the assumptions you make for a designer. The fact is, the argument for God as designer requires many assumptions, not least of which is the assumption that the book you are basing your belief is true. Evolution, on the other hand, makes no assumptions as it is an explanation for observable data.The reason why evolution is a theory is because it is falsifiable. We can go out there and make observations and collect data in the natural world and try to disprove evolution. The reason why God is not a theory is because we can't disprove the existence of God just like you can't disprove the existence of the FSM.But in science, a theory is the highest attainable status. That alone should tell you how well evolution has stood up to all the evidence.I believe that all of us have adequately explained how the complex heart could arise. The fact is that our heart is the result of eons of accumulated changes from a simplistic tube to what it is now. Evolutionary theory suggests similarity across the board, which I have shown you. The problem is, I am not a geneticist, nor is our understanding of genetics complete so I couldn't tell you the genes you would need to change to produce those results. But we know enough about genetics to know that a single mutation can have a profound impact on an individual. If one mutation can affect an organism so greatly, why can't one mutation change the structure of an organ slightly?Ultimately, the evidence for evolution is strong whereas the evidence for a deity is non-existent. Remembering that science is about what is falsifiable, to argue a deity is to stop arguing through science because there is no way we can prove a deity doesn't exist. Regardless of the existence of a deity, the falsifiable naturalistic explanation is the focus of science and that is why evolution is science. The fact that you can say that you didn't "create" God without evidence for that statement shows why religion has no place in science.(I am not going to edit this further so I apologize if it seems a bit unwieldy or disorganized.) *: ABEEdited by Izanagi, : No reason given.