Design evidence # 111: The heart

Demonstrably false bull excrement.Which suggests an extreme level of ignorance of comparative anatomy and embryology.There are many species with much simpler "designs" of heart. Fish have two-chambered hearts, and many amphibians and reptiles have three-chambered hearts. Furthermore, in embryonic development, three-chambered and four-chambered hearts emerge from two-chambered ones; the heart splits in two, becoming two sub-hearts.Also, human embryos, like amniote embryos in general, go through a phase where their circulatory system has a very fishlike configuration, with ventral and dorsal aortas and aortic arches next to the gill bars. Some of those arches then self-destruct, which is an illogical way to install plumbing.Finally, where does sonnikke get those numbers? Is he referring to some big list somewhere?

Sonnikke:
Your(evo's) beloved "mutations" which are supposed to increase information and "create" new specified complexity, does the exact opposite.Except that some sorts of mutations do create information, such as gene duplication.The heart is incredible, the amount of work it does day in and day out. It's layout and design coupled with the interdependence on the brain and nervous system is very strong evidence of specified complexity.Except that hearts and brains have coexisted for all of their evolution from much simpler structures. And in a sense, the brain was first, in the form of the simple nervous system that cnidarians and comb jellies have.If you tried to give a step by step description of how the human heart might have evolved, what kind of story would that be?Here goes:In the Vendian, just before the Cambrian, a little ocean-floor worm was born that had a strange birth defect. It grew an extra throat in its body cavity -- a throat which reflexively swallowed. But that swallowing kept its body fluids in motion, enabling it to nourish itself better. And as a result, that lucky worm's descendants multiplied and multiplied, with that extra throat becoming a heart and blood vessels. And sometimes multiple hearts, as with earthworms.Sometimes this heart would grow extra flaps of skin inside of it. But one that grew in the right place would act as a valve, thus the origin of heart valves.A simple tube of a heart is widespread in the animal kingdom. However, land vertebrates faced the necessity of supplying a lot of blood to the lungs in order to get oxygen and dump carbon dioxide. Which forced the gradual splitting of the heart into two sub-hearts. This was only partially completed in most amphibians and reptiles, but completed in mammals and archosaurs (crocodilians, dinosaurs, and birds).

This extra-throat-to-heart scenario may seem farfetched, but some recent work does point in that direction. Checking on PubMed, I found several papers on a heart-throat connection. I searched for "tinman throat" and "tinman pharynx", where tinman is a gene involved in heart development in the lab fruit fly Drosophila. It was named after the Tin Woodman of the Wizard of Oz, who had had no heart.That gene is related to NK2 genes involved in development of hearts and throats of zebrafish, Xenopus frogs, chickens, and mice, and even to a throat-development gene of nematodes. And the authors of one of those papers note

quote:

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The overlapping expression pattern of NK2 class homeobox genes in the heart and the pharynx may suggest a common origin of these two organs.

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So every time your heart beats, it "swallows" blood. Gulp, gulp, gulp, ...

Sonnikke:
I would argue that this system is irreducibly complex.
If you take away the heart, the system breaks down.
If you take away the brain, the system breaks down.
If you remove the blood vessels, the system breaks down.
If you remove the nervous system, the system breaks down.They all have to be in place and working properly, or the system breaks down.Except that there are numerous organisms that have neither a circulatory nor a nervous system.Many plants have a sort of circulatory system, but no plants have nervous systems.There are some primitive animals with nervous systems but without brains or circulatory systems. Cnidarians (sea anemones, jellyfish, etc.), for example, which have non-centralized nerve nets.And it's not difficult to image some early cnidarianlike animal evolving hearts and brains. Not very fancy ones at first, but enough to give it an edge.(my account of how the heart originated)
This is a very cute story or "just-so" story, but it is nothing more than that (no offence Ipetrich).And why do you come to that conclusion?And why don't you study embryology some time? A human heart starts off very much like a fish heart, and it splits into two sub-hearts as it grows.The fact is, the heart, the brain, the eye, these are just a few examples of the immense problem evolutionism has in trying to explain how they might have evolved (except for cute just-so stories, of course).Sonnikke, what would you consider an acceptable nontheological explanation?

sonnikke:
How can you compare a single celled organism to a heart?Bacteria don't need a heart or blood vessels; all their circulation is done by diffusion. And they are small enough for diffusion to be satisfactory for them; it's only big organisms that have blood vessels and sap vessels.So there is a simple way to live without a circulatory system: be tiny.And secondly, what part of a bacteria could you remove and still have it fully functioning?There's a "Minimal Genome Project" intended to address this very question. Basically, it's about constructing the organism with the smallest genome that can make it still be an organism -- though one that takes all of its molecular building blocks from outside.And irreducible complexity can easily be produced by evolution. All that is necessary is to remove some scaffolding on the way. Consider the evolution of air-breathing from water-breathing animals. The intermediates had been able to breathe both, though their air-breathing descendants are unable to breathe water -- even completely aquatic ones like cetaceans and sirenians.How many beneficial "defects" do you know?"Defects" that help bacteria and insects resist efforts to kill them -- beneficial to them, of course. The evolution of immunity to antibiotics and pesticides is well-known.Also, bacteria are known to evolve the ability to eat substances that had not existed before the chemical technology of the past century, like nylon oligomers."Conclusion: Mathmatics do not support the theory of evolution as
it is currently concieved. Mathmatically there is a zero probability
for any kind of cell development by haphazzard chance alone.That's the one-big-jump probability -- which is NOT zero, even if extremely tiny.However, evolution works by steps, and working in steps improves the probabilities enormously.This, of course, is why evolutionists wish to claim that evolution and
abiogenesis are two separate subjects, and that they do not wish to
answer questions about abiogenesis.One species from another (evolution)
Life from nonlife (abiogenesis)are completely separate questions.Who would wish to defend two untenable pieces of rubbish at the same time? This does, however, leave them having to defend the following insane proposition:
(the seeding hypothesis...)However, that is too much of a deus ex machina; it can account for anything, and thus really nothing. It is entirely possible that the Earth was seeded with its first life about 4 billion years ago by time travelers who wanted to ensure that they'd come into existence, but what positive evidence is there for such a possibility?... How does a system that "bathes" the internal organs with blood, create the necessary vessels and arches and force mechanisms to become closed, while at the same time remaining functioning. ...Actually, some animals, like annelids and arthropods, have relatively primitive circulatory systems. Their hearts are only simple tubes and they have only a few blood vessels.

Sonnikke:
1. Please explain how you would test this theory.Since I don't have a time machine that I can use to go back in time and study Vendian ocean-floor worms, I'm stuck from working backwards from present-day-organism features and what can be preserved in the fossil record.The ultimate test will come as more is learned about how genes specify the shapes of body parts -- does a heart go through a phase where it develops just like a throat? There is some evidence of that, as in the NK and tinman genes, which is why I mentioned that hypothesis.2. Please explain how the worm originated.A question entirely separate from the question of the origin of the heart.3. Please explain by what law and mechanism an open circulatory system could transform itself into a closed system.The ends of the heart elongate, becoming blood vessels. They repeatedly branch, which helps them service organs more conveniently. The ends develop some affinity for meeting each other, which ultimately closes the circulation.And there are present-day animals with open circulation, like arthropods with their "hemolymph".4. Please explain how a birth defect could "create" a whole new organ.The original heart was not a complete four-chambered heart like a human one, but a simple muscular tube -- much like a throat. And many present-day animals have similar sorts of hearts.5. Please explain how the system transformed itself step-by-step, while remaining fully functional.How would any of these steps render a heart nonfunctional? I don't see how that's the case.6. Please explain how this scenario translated into higher organisms in a step-by-step fashion.???7. Please show what evidence there is for this theory.What evidence would be satisfactory in the absence of a time machine?

Except that Ernst Mayr's comment was written 33 years ago. Sonnikke must have a fondness for out-of-date books.

Sonnikke:
No I just have a fondness for illuminating quotes by evo's, and, regardless mutations are still as useless as ever at producing the kind of "believed in" change, that the evo is hoping for.
(snipped for brevity: another one of his possibly-bogus old quotes)Let's interpret the Bible the way that Sonnikke interprets the writings of evolutionary biologists. Thus, "Happy is the one who smashes your babies against a rock" (Psalm 137:9) is direct Biblical support of baby killing.And Ernst Mayr's alleged statement is actually a criticism of the view that some evolution is caused by macromutations, mutations with large effects. He is claiming that "good" macromutations essentially don't happen, which is justified by extrapolation from many known macromutations.However, the good-macromutation hypothesis is starting to make a comeback, as evidenced by some recent "evo-devo" research -- this sort of hypothesis is becoming testable! Some recent examples:Both Drosophila fruit flies and Artemia brine shrimp have Ultrabithorax Hox genes, which are expressed in their rearward segments, and which make those segments develop as "proper" rearward ones. However, the fly version stops legs from forming, while the shrimp version does not -- and the shrimp version in a fly makes the fly try to grow lots of abdominal legs.So a few mutations in the Ultrabithorax gene may be all that's necessary to go from shrimp rearward legs to insects' absence of such legs.Likewise, snakes have a pattern of Hox-gene expression that contains no front-limb zone, as other vertebrates do. Thus, they don't grow front legs. They may have gotten a mutation in an Hox-gene-control gene that moves a bit forward the expression of one of the rearward-expressed Hox genes.

Actually, some human designs do tend to acquire that property -- computer source code maintained by several people, for example.