Oxygen and insect size

Are there any other sources that say there was more oxygen in those days? I somehow got used to a different opinion (maybe it is wrong, but nevertheless I have repeatedly met). For example, the intensity of photosynthesis increases under conditions of a higher concentration of carbon dioxide (and, accordingly, a lower concentration of oxygen), which is usually interpreted as the formation of this process under the appropriate conditions.

it was exactly up to 31%
Experiments were carried out with coconuts, successfully, we got dragonflies of 20 cm in wingspan.

all that I managed to dig up:
the leading specialist in this matter, John Van den Brooks
publications:
https://scholar.google.ru/citations?user=pBOZfHQAAAAJ&hl=ru

I have doubts that no one else has conducted experiments other than john

But isn't the problem with insects the same as with swimmers with a mask and a breathing tube: at a certain critical length of the tube, the volume of inspiration is not enough for fresh air to reach the lungs? If so, then increasing the oxygen concentration won't help.

It's not a matter of inhaling. Those insects that perform active respiratory movements (and not all of them do) fill only the main tracheal trunks, and then oxygen enters through the repeatedly branching system of tubes up to each cell of the body due to diffusion. So increasing your concentration will help.

So much the more so. We have a narrow tube through which something must move due to diffusion. The tube is so narrow that all sorts of capillary phenomena become noticeable. True, I don't remember colloidal chemistry in practice, but my intuition tells me that it's not the concentration of the substance that will be important here, but the size of the lumen.

Usually, capillary effects are considered in relation to liquids. Pedivikia is silent about gases. Trachea in the end part-they are, of course, narrow, but IMHO not so much as to interfere with the free movement of gas molecules. Of course, if they were wider, it would be easier for insects to breathe. But there is what it is. And the difference in concentrations is the driving force of diffusion. Accordingly, the more oxygen in the atmosphere, the more it will get into the insect's cells. In general, there must be modern works devoted to the study of the process of insect respiration from the point of view of biophysics with the construction of complex mathematical models that take into account various effects, including from an increase in the concentration of oxygen in the atmosphere. So try looking for them. I was not interested in this, as it lies very far from the area of my scientific interests.

it was exactly up to 31%
of the experiments were carried out with coconuts, successfully, we got dragonflies of 20 cm in wingspan.

What kind of coconuts?
Interseno, can you link to such details? ) Potsom what is strange about all this, in theory, the size of insects b / m is genetically determined, but what happens if the wasps grow in an atmosphere with 35% oxygen, they will not fit in their cells? The cell sizes are then exactly genetically determined , or not? ))

The size of the cells (width) is determined mainly by the size of the head of the imago that built them. And how the latter are determined is a separate question. In wasps (solitary), by the way, the phenomenon of the dependence of body size on the amount of food in the cell is well known. If you artificially add additional victims, you can grow a giant.

The size of the cells (width) is determined mainly by the size of the head of the imago that built them. And how the latter are determined is a separate question. In wasps (solitary), by the way, the phenomenon of the dependence of body size on the amount of food in the cell is well known. If you artificially add additional victims, you can grow a giant.

Well, hello.. And how are drone melifer / uterine vespula cells built? Not only do your polysts happen to have all the same cells )
From the amount of food yes, the size changes a little, and not only wasps, there are anomalies in beetles and in general in all living things and vegetation, but, after all, there is clearly an oxygen restriction for tracheal breathers, the only question is what mechanisms restrain the growth of insects - genetically predetermined or the size depends on the concentration of oxygen directly. And even it seems to me that it is genetically, which is obvious, the size of insects is somehow shifted to "small" areas, insects in evolutionary terms are trying to become smaller, not larger, and this is not for nothing So it is very suspicious about dragonflies of 20 cm in span, maybe they overfed them ) In the tropics, conditions and food are better, but even there, the size is certainly slightly larger on average than in the middle zone, but there are also enough small things.

Is oxygen better in the tropics, too? I don't know anything about the construction of bee cells, they have a hexagon cell in general, regardless of the OS, and maybe the measurement mechanisms during construction are different. But I have good reasons to believe that the original mechanism for determining the width of the cell aperture in social vespids is based precisely on the width of the head and, partly, the chest of the construction wasp. And yet the polists here just "stand at the origins". The Vespulas ' differentiation of cells by size developed a second time, along with a similar differentiation of castes, so it seems that they "invented" something for this purpose. But here we should not forget that the uterine cells are no longer built by the microstrips of the first broods that built the cells for the workers of subsequent broods, but by the most recent workers, that is, the largest. Given that the size difference between the workers of the first and last broods is almost the same as that between the latter and the queens, it can be assumed that the vespula's measurement mechanism is also based on some morphometric parameter of the body, but only, unlike polysts, they take with a margin. What is primary: cell size or caste differentiation of the larva? Do workers build large cells specifically for queens, or do larvae develop queens precisely because this happens in large cells (plus more food)? Probably, in reality, several factors work together. In bees, everything is much simpler and better researched in this regard.

Insects tend to get smaller. because it is beneficial in evolutionary terms - there are more free ecological niches for small things. I am sure that if there were no vertebrates, the number of large insect species and their size would be much larger. But the basic organization of the vertebrate body is more favorable for large sizes. The insect in this niche obviously loses. Even if you don't take into account such well-known limitations in scaling the size of insects as tracheal breathing problems and the mechanical properties of the exoskeleton, imagine how much time an insect the size of, say, a cat would have to spend solidifying after molting, and what would be the probability that someone would eat it during this period of absolute helplessness. Agree, here the same cat has an undeniable advantage. Does this mean that the organization plan of an insect's tala is less versatile and flexible than that of vertebrates? No way! But in fact, insects already have the largest size range among all land animals. And the number of species speaks for itself. It's just that the upper limit has been reached in the current conditions, and it turned out to be "small" on a human scale. But that's the man's fault for being so big.

This post was edited INO-26.10.2015 20: 54

I think in the tropics with oxygen is much worse, first of all, humid, hot - all this contributes to a drop in the content of O2, + also active oxidative processes against the background of almost zero positive oxygen production.
So the large size of insects in the tropics is clearly not related to oxygen.
I don't know how it is better researched in bees, but I didn't see anything about the mechanisms that promote the retention of a certain cell size. How the uterus determines the cell size is easy)
Workers build cells specifically for queens or drones, such as Melifer, Germanicus, and then resp. feed future queens/drones in a different way. This is easy to show, in wasps the larvae are more independent - they decide when to stop eating and close their cell themselves, wasps, as far as I know, feed their queens exactly the same as workers, unlike bees, but at the same time the uterine larvae somehow know that they are supposed to eat longer and at the same time time to stop eating at the right moment. And since there is no other way for the larva to find out that it is a uterus, except for the size of the cells, and the sizes of the uterine and working cells differ in leaps and bounds, without transitions, then the wasps " build cells specifically for queens."

About the size of the OS, this is again a pen, but what is it)) Well, this is already quite, but there is no such difference between the last and first wasps-vespula and close! You will calculate and write what sizes the first workers should have if you take the difference between the last workers and the uterus?
That's how the frosts will be I will disassemble the germanic nest and measure the width of the upper cells and the last tiers of workers, you are an Esox as an academic scientist, take it and predict the difference in these sizes, since you claim such a difference in the size of adult os

Since when do turtles have an exoskeleton? The carapace serves them for completely different purposes, and the skeleton, like all vertebrates, is internal. Your revelations are becoming more and more astounding to me. Although I've already said that.

"Internal chitinous strands" are just difficult to implement due to the specifics of the insect's anatomy. After all, the chitinous cuticle is part of the integument, and during molting these strands should either be discarded (which is difficult to imagine) or dissolved, being replaced by soft ones that stretch in the process. Such elements of the endoscope are present in spiders and, to a lesser extent, in insects, but this system has not received strong development, obviously, precisely because of the problem described above. Vertebrate bones, with their growth mechanism, are quite another matter.

I meant that bees have a better understanding of the mechanism of caste differentiation of larvae, in which royal jelly plays a key role. The OS does not have milk. And the size of the germanic workers does increase greatly from the beginning of the season to the end, how can this be without increasing the size of the cells? I will not say that the difference in size is as large as with the uterus, but it is the size of the same strand.

Since when do turtles have an exoskeleton? The carapace serves them for completely different purposes, and the skeleton, like all vertebrates, is internal. Your revelations are becoming more and more astounding to me. Although I've already said that.

Well, let's say Esox himself came up with the idea that the turtle shell is an exoskeleton, I didn't write this, I just suggested paying attention to turtles that live with an outer thick shell and don't sweat. At the same time, the carapace is several times worse than the exoskeleton itself, because the latter can have mobility, segmentation, covers both paws, etc.and so on.
So what is striking is just your limited thinking and stereotypical

As there is something to implement, it is to the Almighty, evolution, well, or development in our opinion, it is quite a flexible process, there is nothing impossible Strands may not be chitinous, or they may be chitinous, but organized like vertebrate bones. In any case, this case is definitely not a problem for increasing the size)

And who said that animals should "steam" from a thick shell? They should" steam " from the lack of an endoskeleton at large sizes. The turtles are doing fine in this regard.

I wonder how the lack of an endoskeleton will prevent large sizes?

Mdya.. Esox.. did you put all the apricots on the apricot stand and drink it all today? ))) You have gallicuses, and dominuli, and differences in their sizes, both in cell widths and in the os imago, which you should know well(although.. judging by the statement that the gallicus is half the size of the dominant-not the fact that hrosho .. And there are the expected differences in both the size of the imago and the cell diameters of the late working germanics and the early ones..
What castes, aww? And are they even here? ))))

Well, okay, I persuaded, I predict: with a probability of 100%, the size of germanics of any caste and brood in the city of Nikolaev is not enough for the portions of poison administered when stung to be enough for a therapeutic effect in relation to violations of the cognitive and speech functions of Mr. Hierophis. In this regard, we can recommend repeated exposure with application points as close as possible to the brain. This concludes the conversation.