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whatissevenbysix t1_ityj09s wrote

Directly under the egg's shell are two membranes. When the eggs are laid by the mother they’re very warm, and as they cool the material inside the egg shrinks a little bit. The two membranes pull apart a little and create a small pocket or sack of air. As the developing bird grows, it breathes in oxygen from the air sack and exhales carbon dioxide. Several thousand microscopic pores all over the surface of the egg allow the CO2 to escape and fresh air to get in.

Full article here

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benvonpluton t1_ityl5rl wrote

Air can pass through the shell. As a matter of fact, that's why dinosaur eggs weren't much bigger than an ostrich egg even when the adults could be 30 or 40 meters long : a bigger egg would have needed a thicker shell, which would have made it impossible for the air to pass through.

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Upset-Ad4844 t1_ityqz3z wrote

Great answer, but one quick correction. They are not breathing (using lungs) until they hatch, however they are respiring. I have to confess my ignorance on the exact mechanism, but the membranes seem to allow for the O2-CO2 gas exchange to the blood.

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sifterandrake t1_ityrch5 wrote

Now, for the important question. If I surrounded myself in chicken eggshell, would I be able to breath? (assuming it was egg shaped, just big enough to fit my body and a reasonable air pocket.)

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ZairyMonkey t1_ityu9wo wrote

Oxygen and CO2 can pass through the shell. I learned this recently when hearing that one method for controlling the Canadian goose population where I live is to find the nests, distract the parents, and paint the eggs with a thin coat of cooking oil, which blocks the o2 in, co2 out process. The adults don't notice and continue caring for the eggs but they simply never hatch.

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VictorVogel t1_ityuc13 wrote

According to google, a newborn chick weights about 38 grams. Lets assume an adult male weighs 80kg, so that's 2105 times as heavy. The third root of 2105 is 12.8, so an adult human sized egg would have sides of 12.8 times a normal egg, the surface area would be 12.8*12.8 = 163.84 times as big, and the amount of surface area per mass is roughly 12.8 times as small. It will be a lot harder for the human to breathe. This all assumes that the human egg shell is equally thick.

I'd say it is unlikely.

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more_beans_mrtaggart t1_ityvejp wrote

The air sac is at the rounded end of the egg.

When boiling eggs, make a hole in the rounded end of the egg (I use a fork tine) the the bubbles will come out rather than the shell splitting apart as the cooked egg expands inside the shell.

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kenobismom17 t1_ityvgmg wrote

That's like next level infanticide. Smother ... let the geese keep their growing excitement for parenting.... then watch the geese be sad. What's good for the gander isn't always good for the goose.

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emmyarty t1_ityy5bk wrote

Another quick correction: respiration is not the biological term for gas exchange, but rather the process by which usable energy is released and made available to cells. That's why anaerobic respiration is still a form of respiration.

Breathing is still the most appropriate way to describe lungless gas exchange, whether it's fish breathing through their gills or lungless salamanders breathing cutaneously.

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silent_cat t1_itz4rmc wrote

And the reason they do it this way is because if you remove the eggs they just lay more.

The same things works for pigeons by the way. You get them to lay in a special nest where you simply make sure they don't hatch.

Though in this example they simply shake the eggs, which is apparently enough to prevent them hatching.

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JennaSais t1_itziw9q wrote

Great corrections, but one more quick correction (because I want to play too!) They don't wait until they hatch to start breathing, they start breathing when they pip. That is to say, inside the shell, they break the air sac and begin to breathe, and then they make their first hole in the shell. At this stage you can often hear them making their first peeping sounds, even before they've "zipped" (which is when they start pecking a line open around the shell, and the stage at which you can typically catch your first glimpse of the emerging chick.)

I have some quail eggs I'll be setting soon, I'll try to remember to film!

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JennaSais t1_iu05odf wrote

Right? Another fun tidbit is that the earliest chicks' peeping sounds stimulate the latecomers to work to get out as well, so you can see some very early social behaviors with them as well.

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penny_eater t1_iu09s6s wrote

The air has to come out somewhere as it expands. Sometimes it can get out through the micropores in the egg and sometimes it can't and the shell cracks. Has nothing to do with if its overcooked at all, as the trapped air will be the very first thing to get hot during cooking.

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burningmanonacid t1_iu0cnat wrote

Am glad to see this this far up. More than air can pass through the shell too. In Ireland, they used to use butter all over eggs to close the pores and keep them longer according to a book I read before. They could be kept for much longer than normal like that and also come out tasting kinda buttery without needing to add it.

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ecksate t1_iu0eun0 wrote

Spectacular corrections, but one small tidbit that's barely related but does break some reasonable assumptions: human babies, at some point in development, do some amount of breathing, and what they breath in and out is amniotic fluid (just for practice, not for gas exchange.)

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lazy_smurf t1_iu0jw1p wrote

Diffusion and respiration are both correct but from different perspectives. Diffusion is focused on the molecular movement (chemical/physical perspective) and respiration is focused on the organism's processes (biological perspective).

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paul_wi11iams t1_iu0m3yx wrote

> you can see some very early social behaviors.

Here's a more cynical take on this:

As a chick, I'd do the same, hatching just after the first. So the first-hatched would keep any predator busy while I get out of my shell and improve my own chances of survival.

It compares to zebras running close-packed, each improving its individual chances because the lion will catch only one.

Edit: Thinking further, I concede that there could be a big overlap between social behavior and selfish gene survival. For example, the first to hatch could be helping out its siblings by offering itself up to a predator.

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Omnizoom t1_iu0s1bx wrote

One extra tidbit to add , our lungs are very capable of exchanging oxygen and co2 with a liquid so even amniotic fluid would be able to do a chemical exchange

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cranfeckintastic t1_iu1ymg4 wrote

The blood-vessels that form inside the shell would be what absorb the oxygen and transfer it to the chick. It's the same sort of thing with reptile eggs, save they tend to have a slightly larger air pocket and, unlike bird eggs, can't be moved from the position they were laid in as it runs a high risk of smothering the air pocket and suffocating the embryo.

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Omnizoom t1_iu2n0jh wrote

Because water is a crappy source of oxygen compared to air , but if you were to breathe a oxygen rich fluid that can also absorb co2 then your body will be able to use it

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