Hrvoje

African lungfish circulatory system

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38 minutes ago, Hrvoje said:

The gas contained in swim bladder can be air, if it is inhaled from the outside, which can be done only if pneumatic duct is present. Otherwise, it is whatever is produced by a gas gland, and that mixture of gases is not air. For instance, the eel Synaphobranchus has been observed to have 75.1% oxygen, 20.5% nitrogen, 3.1% carbon dioxide, and 0.4% argon in its swim bladder. 

This is not "my" diagram, it was obviously created by people who are seriously engaged in science, unlike you, and it would be silly to take into account your objections about that diagram.

Besides that, if you think that my question is a "strawman", whatever that means, stop posting here.

If you don't know what a strawman is I would suggest you study some logical fallacies... The eel you mention has nothing to do with lung fish.

https://www.britannica.com/animal/lungfish

Quote

Adaptations for breathing

There are a number of fishes that, in addition to or in place of gill breathing, have developed special organs through which they can breathe atmospheric air at the water surface. This occurs almost exclusively in freshwater fishes. In lungfishes these organs are, both in function and in structure, primitive lungs like those of amphibians. The name lungfish is thus well applied: these fishes have lungs that are derived from the swim bladder (an organ used for buoyancy in most bony fishes), which is connected to the alimentary tract. The inner surfaces of these air-breathing organs are covered with a great number of honeycomb-like cavities supplied with fine blood vessels. As in terrestrial higher vertebrates, gas exchange takes place in tiny air vesicles. Also as in terrestrial vertebrates, there is a separate pulmonary circulation.

Your diagram ignores the origin of the air and this makes it incomplete and inaccurate... 

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39 minutes ago, Hrvoje said:

Besides that, if you think that my question is a "strawman", whatever that means, stop posting here.

!

Moderator Note

Whoa, participation isn't up to you. Disagreement happens in science, and it's generally considered a good thing.

And when someone accuses you of putting up a strawman of their argument to make it easier to knock down, the proper thing to do is show how it isn't, or admit that you missed the mark. When someone calls strawman, it means you haven't addressed their real argument, and so the discussion spins in circles, and nobody wants that. It's not a personal attack, it's a request for clarity.

 

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Request for clarity? I think all my questions were clear and legitimate, and not "fallacious" in any way. Whoever thinks otherwise, doesn't have to answer to them.

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1 minute ago, Hrvoje said:

Request for clarity? I think all my questions were clear and legitimate, and not "fallacious" in any way. Whoever thinks otherwise, doesn't have to answer to them.

!

Moderator Note

This isn't how discussion works. If it did, you might never know people had no idea what you were asking. 

If you aren't going to respond civilly, you should start a blog somewhere else. If you can't, there's no reason to keep the thread open.

 

 

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On 25. 12. 2017. at 4:43 PM, Endy0816 said:

Lung is good at gas exchange now, it wasn't originally.

If we imagine there are hard divisions between systems, then we might say as it evolved it later fell under the circulatory system.

I was partly demotivated to continue this thread by misunderstandings that appeared during this discussion, partly drawn away by other interests, but this post deserved an answer. I can only second that opinion. When and how did it happen? For this important event in african lungfish evolution to happen, not only alveoli and bronchioli should have been developed, but also the new circulatory network that supports their function, besides the original, that was retained in a tissue from which the lung was formed. How do we know that? Well, unlike the first diagram posted here, that is perfectly fine, double circulatory system diagrams, which are probably the most popular circulatory system diagrams on the internet, usually have slight deficiency, when they are not followed by an explanation of the fact that heart and lung tissues are supplied with  oxygenated blood by systemic circuit capillaries too. While for heart it may be clear that although it receives massive input flow of blood through largest vessels in a body, it cannot utilize it for its own needs, it still needs tiny capillaries to exchange CO2 for O2, and these are of course part of systemic circuit, for lungs one might think they can utilize pulmonary circuit for both functions, to oxygenate blood for the needs of the whole organism, and to use some of that oxygen for themselves, so that they don't need
systemic circuit at all, but the fact is that systemic circuit is evolutionary "older", it is descendant of the ancient single circuit, while the pulmonary circuit is evolutionary "newer", developed for the respiratory function of lungs, and the tissues from which the lung was shaped obviously needed blood supply before pulmonary circuit was developed, so that they still have it in a form of bronchial circulation, that is part of systemic circulation. In other words, old vessels didn't disappear, but the new ones appeared, that were meant from the start to connect lungs to heart in a new way, and to support the new function of lungs.
However, we see that genome is capable to produce tumors, and to develop completely new vessel network for their needs, during the lifespan of a single organism. What if it is also capable to produce the complete and novel beneficial remodelling of blood circuitry in one organism, and write down that change in its code to pass it to further generations? I mean, people see that organisms changed throughout history, we can roughly estimate when some changes occured, but we are obviously clueless about the dynamics of these changes. Who can say if lungs appeared during the lifespan of one, thousand, or million generations? Only time.

Another thing that postponed participation for some time was a weird obstacle that I have when I try to sign in with Facebook authentication. It displays a message:

>>App Not Setup: This app is still in development mode, and you don't have access to it. Switch to a registered test user or ask an app admin for permissions. <<

I wonder am I the only one who received that? I wrote to forum staff about the issue, but received no response. So I decided to create a new account to continue my participation until the issue is resolved.

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Angiogenesis occurs normally in healing. I think it is normally limited to particular cell types, but all the cells share the same DNA so...

 

You may need to look at embryology or maybe even seek a professional in the field. Honestly, I don't know what to tell you besides saying I've seen great evidence for successive changes over time and none at all for something to spontaneously occur and somehow get itself into the germline.

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Yes, it occurs normally in healing, abnormally in cancers, and vasculogenesis normally occurs prenatally, neovascularization also has its distinctive meaning as Wikipedia says... it is nice to be informed about the terminology, sometimes very important.

There are some professionals in this field here on this forum, probably not very interested in this topic, and I don't blame them for that.

And I agree this sounds very strange as this flow of information contradicts the central dogma of molecular biology.

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