How come humans dont lay eggs? [Citation needed]

Because humans also eat eggs. It would be too tempting at times.

What are you talking about ? Have you never seen a woman lay an egg?

Well they do sometime. But only in the presence of a megasperm .

Okay, so the harsh news is that animals can get egg-bound. But let's address the issue. How big is that egg going to have to be? So the egg would have to be small enough to easily be laid. Then, and here's another kicker, they aren't going to get bigger. Unless possibly we lay them in water. So the baby has to develop enough while being small enough to fit in the egg. Then they have to hatch. Now, either we break the eggs to get them out (counterproductive), or they get out themselves. Elephants don't lay eggs. Bears don't. None of our fellow apes do.

We're just the lucky ones whose offspring will, unless we draw a bad hand, someday be able to live lives as adult human beings who might enjoy whatever jobs they do.

Good question.. thinking about it new born human babies are more fragile then babies of other species

Wouldn't the egg be the same size as a baby? I am a bloke with 2 kids and my OT had to have a Caesarean Section for both kids. The thought of her having to give birth to a full size egg is horrific.

I do.

I'm very ill.

Because dinosaurs put all their eggs in one basket and the Chicxulub asteroid impact ended them all. That’s why one of human’s ancestors the first placental mammal said fuck that and started to have live babies for risk management and gradually filled the new niches

Because if humans were to lay eggs, the abortion centre will be out of business

This is just my opinion. I’m not claiming to be an expert here but I’d actually argue that laying eggs is not safer. If you lay an egg, you need to protect the egg from enemies and other prey, whereas with humans we carry our babies inside, so in a sense the womb acts like an egg, except we have to carry it everywhere so it can be protected at all times instead of leaving it somewhere to hatch later.

Obviously there is a danger to the mother and there are certainly risks associated with childbirth, but there are also plenty of risks associated with laying eggs too.

Also, human brains are far more complex that most other animals that lay eggs, which is likely part of the reason why we require constant nurturing and a relatively larger incubation period and it’s much easier to keep babies safe if they are in our womb as I mentioned above.

Remember as well, evolution isn’t always about us simply evolving certain traits for a specific reason. Often evolutionary changes can be random, however if there is a benefit to that certain mutation or trait, then there is a higher chance of survivability, meaning there is a higher chance of that trait being passed on. This means that at whatever point in time we evolved to have live births, this was advantageous and resulted in more animals with live births surviving and reproducing.

We’d eat them and go extinct

What do you mean? The spoiled ones always come out at the end of the month all together with a part of the uterus that would accommodate a new human if that egg would be fertilized by a little espermatozóide

We do. One comes out roughly every month. They're just too small to see.

Neurological complexity.

Biologic investment.

Use a chicken for comparison. 18 weeks from hatching to sexual maturity. Some chickens lay 300 eggs per year. 21 days of brooding the egg<s>. Upon hatching, that chicken has to brood a chick for 3-6 weeks. Chick has 3 to 6 weeks to engage in resource consumption. The hen has to fuel itself to brood for approx a month and a half.

Chickens don't care about their eggs. I've seen them walk across the yard, squat down, lay an egg, and walk off. <fwiw-theres some humans like this-cptsd thread>

Carrying a fetus for more than a year and nourishing it from a developed digestive system is MUCH more efficient and required for the complex neural systems that mammals have in comparison to birds, fish and reptiles. It's part of why we get fat so easily. Feed your babies as much fat as you can-those lipids are what fuel brain growth-direct conversion. Lotta recent research recently into White sharks is astounding the behavioral modification that occurs between predatory fat consumption vs protein heavy consumption.

There are some reptiles that live-birth, internally those are still eggs, and they hatch inside the reptile. Birds are rigged for flying/swimming-even the flightless ones, carrying a fetus or even an egg internally is problematic.

Our anatomy isn't really very well made for live birth and eggs would be even worse. Our hips are too narrow and babies head to body ratio is too big. About half or births are C-section but if we laid eggs (hard-shell eggs) it would be impossible to give birth naturally.

The reason, if i remember correctly, is that life evolved to hatch the egg inside the womb and develop the child so that when it is birthed, it has a much better chance at survival.

This may slow down gestation in the female but the trade off is that the newborn can run and bound immediately, allowing the mother to keep an active lifestyle and evade predators and hunt for food. A good example of how eggs are harder to deal with is mother birds not eating while they guard eggs.

Now some mamals still give birth to infants that are pretty helpless. Dogs puppies are pretty helpless but they mature very rapidly and would have longer to go if they hatched from eggs externally( all animal life pretty much will be from eggs. Human eggs are the width of very fine hair.)

Heres the big part: humans evolved such large brains that the female womb was not really large enough for the normal pattern of gestation for mammals. If we go by averages of the animal kingdom, then humans should gestate for like 15months or some silly thing. We need to birth our young much sooner than other mamals in our weight class because our heads and brains wouldnt be able to fit if we let them grow into a toddler first. Which is what you see in deer and horses and such their infants are standing up in the first few hours.

Mamals have taken over the planet due to this method of reproduction being vastly more reliable than laying eggs, hoping they survive or starving yourself to guard them or leaving to get food while raccoons raid your nest.

They do, but the egg is fertilized and carried by the woman developing into a fetus until born as a baby.

Imagine if women did lay an egg, the chances of a person dropping that egg and killing the unhatched baby are much higher than with a baby.

I read somewhere that amniotic sac was originally an egg like thing, and a virus was determined to push evolution into it no longer being much egg like. Dunno how true.

I know this isn't the place to give serious answers, but the amniotic sac is an egg. It doesn't have a hard shell, but it still contains an (empty) yolk sac for example.

I am human and i lay eggs, its shitty of you to assume my egg laying capabilities are lacking. Just because you cant lay eggs doesent mean we all cant lay said eggs. Shame on you, be better.

Expensive

Humans aren't physically strong enough to defend themselves, nor can they put eggs in unreachable spaces like birds or hide them in nooks and crannies like fish. If we were to be an egg laying species, women would look alot different so that they can put eggs enough size to be a human. Before you say small egg becomes larg baybe. It would require you to feed the child quite alot

We are mammals.

Imagine the size of that egg🤦‍♀️ Who would sit for 9 months on the thing and incubate it?

You might enjoy reading The Martian Tales.

Ask God.

Women are full of eggs

We do. They just never become viable outside of the body.

We do 1 time a month from age about 12 to about 60

because humans aren't platypi.

https://en.m.wikipedia.org/wiki/Cloaca

Because women don't have cloacas

Why arent babies born in like a sack like horses.

platypus could make their own custard if they wanted to

yeah why don't we have the option of laying our own eggs it would be fun!

Humans lay eggs inside themselves, which are later fertilized

Mammals generally have less offspring than animals who lay eggs. Carrying your offspring with you allows you to provide a more stable and protective environment for it. Basically, evolution said “Quality over quantity!”.

Nice try aliens

Because humans are placentals.

The shells hurt coming out.

We do, I've seen a gif of a woman laying an egg.

The egg laying humans ate each other's eggs. They all died out. So evolution started again along with a few other key early stage evolutions such as laser eyes and unlimited teeth . Sadly in the 1600s these were voted against by the world leaders so evolution removed them retroactively

When you have parasites you do

Because evolution isn’t a cognitive force, it’s a product of circumstance. So shit that works most of the time or just enough can pass the evolution test. Evolution isn’t the result of what is the most efficient or sensible, just what works enough until it doesn’t.

Our brains are too big, most mammals are hence the evolution of eggs and in situ pregnancy versus external eggs hatching

it was forbidden by the great repeal of destiny in 1328

I'm not so sure your statement is accurate:

https://youtu.be/yENmufztolo?si=7DrEzzVY3w0xm6kv

Technically females do lay eggs. But in the same way all mammals do (inside the womb, lay is probably a bad word to describe it though).

Do you mean fertilised eggs like birds and reptiles or unfertilised like fish?

Because we would just loose them and there's no "Find my Egg" app yet.

Women don't have platypussies.

Humans have the highest success rate of keeping babies alive, so seeing the eggs be kept better is anecdotal.

The human egg hatches internally, so there's no chance for it to calcify and be laid. The human egg cell also has no nutrients internally, so any embryo would starve.

In short, humans reproduction is advanced in a way to promote the survival of offspring rather than produce many offspring.

Because we are mammals. Mice are the early mammals they did not lay eggs. Everything else is just an advanced mouse

because female mammals have the ocean in their body.

They do. It's called menstruation.

They used to, but in 1972 the UN passed a resolution requiring live births for all humans.

I would much prefer this. Also idk why anyone is saying it'll be dangerous for the egg from predators? Like we live in houses. We could easily leave the egg in a warm room on a blanket for a couple hours. Like come on lol

To prevent egg crimes. Imagine all the horrible things people would do to other people's eggs.

We're too heavy. We'd crush the eggs if we sat on them.

I just laid an egg after eating too much chili, does that count?

They do, just not external.

Are you aware this sub is a circle jerk or are you looking for actual r/biology?

Either way, the answer is obviously that human eggs would need to be the size of watermelons, and there’s just…no good way to make that work.

Heard of mammals?

I can't even imagine myself laying that.

Having a cloaca would suck, passing the egg would suck even more

I saw article awhile ago that this is because of a bacteria which caused humans to adapt and bear children the way we do

for nomadic creatures like mammals (this includes humans), it's easier to have your kid(s) growing inside you rather than as just an egg you need to constantly make sure is at the right temperature

If you believe in the Bible, God designed us this way to punish women for their Original Sin. Sounds like a lovely God to me. Sure wanna follow him. 🥴

I don't know if you know this, but every 28 days or so, female humans do "lay" eggs that sit around for a few days in-utero waiting to get fertilised, then get expelled if they don't.

You don't wonder why other mammals also don't lay eggs?

Possibly because we (and other mammals) are too complex for what nutrients can be fitted into an egg shell. Birds are simpler.

That's the same shit like when young peeps shave their head bald, do they have a "Birth Complex"???

Do they want back in ?

U asking the internet to do your homework with citations? Think you smart, eh?

Are we talking about humans, or bear children?

You said "laying eggs is the more cautious way" but that is not true. Pregnancy make it infinitely easier to move the future infants. The mother is fully capable of moving a good 60-70% of pregnancy. And even at the latest stage, while it s harder, she can still move and therefore protects the baby. It s a better strategy of defence than sitting on the eggs for months.

Evolution man, we ate up all the eggs of the ones that do.

The stork union threatened to strike.

imagine how big that egg would be to be able to have the space for a baby to grow to full term in it.

The evolutionary choice was made long before humans.

You don't - Uh I mean of course they don't! That'd be silly.
A clutch of eggs that is prominently displayed in the lounge to gestate by the fireplace warmth would be a crazy notion and wouldn't possibly be a viable means for genuine bipedal mammalian lifeforms like you or I to reproduce.
No no no. We genuine humans with human reproductive organs gestate our young in the other way.

Because humans are stupid.

Some of them weren't even sure who their daddy is.

Don't make it more difficult to prove who is their mommy.

Otherwise their brains would melt down.

All Mammals have live births and I think there is only one mammal that lays eggs.

N. S

When the baby kicks, the shell breaks

We sort of do. The mammal keeps the "egg" inside of it's body as protection. It has the same basic components as an egg. The embryonic fluid (albumen) the yolk (placenta) and the shell (the body)

I regularly lay eggs, only they never seem to hatch. I laid one on the bus once but no one else thought it was as cool as I did, they just called me a dirty bastard and threw me off.

we're mammals

😶

because gestation and development occur inside a human females body rather than outside.

Evolution is survival of the “eh, good enough”

Cause you an me baby ain’t nothin but mammals

Humans do lay eggs - they just don't do it externally.

And while there are risks to the Mother in child rearing - I'd say it's still safer on average than laying an egg exposed to basically everything. This is why most eggs have hard shells after all - and those that do not - get hidden/buried and or watched over by their parents to ensure they hatch. They also generally produce way more eggs for this reason - more can go wrong with an external embryo. In-utero is the safest place for Human babies to develop this -is- our superior evolution at work.

I'm what way are eggs safer??

Because mamals

The kiwi lays a single egg that takes up almost their entire body cavity....and many die doing so