Reality check for egg laying humanoid

Question

I have been doing little research about egg laying. Namely ones involving humanoids. General consensus seem be that those two are bad combination. This and some other information I have gathered, has led to conclusion which I want give little reality check. Those humanoids I am talking about are about two head shorter than modern humans and intelligent about on our level when adult. I'll give a short summary of process of their egg laying:

• Female gets fertilized by male's "whiptail".
• Community takes care of female while she is carrying, including feeding her and she will need all that food.
• While inside mother, egg absorbs nutrients and other stuff like antimicrobial chemicals.
• When the time comes, the female pushes out snot in thick leather (sexy, I know).
• This little snotty is taken care by the community, including keeping it watered and warmed.
• Snotty inside is practically a speaking brainless ectotherm for early phases of deveploment.
• Shorty before hatching from thinning leather shell, their brains began to develop a little.
• Once little snotty hatches, they practically speaking have pea soup inside their skulls.
• Community takes care of snotty the moron who can't even maintain their body temperature.
• Once snotty is a bit more grown and less of a moron, mother with regained strength would take care of them onwards (Forgot to add this part).

As time passes, this kid grows, literally gets some brain and becomes able to maintain their body temperature like good endotherms should be.

This question is not about if egg laying humanoids are possible, but rather to check if this conclusion is at least plausible.

edit: Some additional information and clarification.

When I said snot in thick leather, my meaning was nutrient rich yolk in thick leather sack. Or very leathery material anyway. Albeit rubbery might be better term as material is bit more elastic. Pushing stiff sack out would be far more unpleasant.

For brainless my intended purpose was describe something without higher brain functions. Only most basic functions until brain began to deveploment later. Their metabolism also resembles that of ectotherm or cold-blooded creatures, until after hatching.

As for communal need take care of kid, well, if they didn't they would have gone extinc long time ago. It's just that simple. Eusocial would fit these beings rather well, albeit they are far more nicer looking than naked mole-rats.

These beings are to certain degree also nomads, until they finds good place to settle on and build community. Either permant or temporal. If walking upright by two legs is energy efficient, evolving such trait might not have been that unusual. They just missed change to evolve live birth and needed some kind of life hack solution. In short if they don't find good place, no snotties happens. At least time isn't problem without menopause and near good 150 years of longevity if nothing bad happens.

Answer 1

First: That's not how eggs work!!

The idea of laying eggs is basically to have an independent developmental environment separate from wood; the only reason life, or rather mammals, developed an internal gestation system is because it was safer for the offspring in the sense that it was more challenging for predators to consume them. What you're describing is much more similar to a marsupial, which is essentially a uterus with extra steps.

Before answering your question, I believe trying to follow your thought process could provide useful answers to questions that will likely arise later. As I understand it, your reasoning is as follows: The female lays eggs, the embryo stops developing in the safe and controlled environment of the egg before having a minimally functional nervous system and, most importantly, endothermic capabilities. The offspring is cared for for several months to prevent it from dying from literally anything before having a baby that is only 50% more fit for survival. This incredibly complicated system occurs for... for... for reasons.

Congratulations, you have literally described the worst characteristics of oviparous, marsupials, and primates in a single species. If we strictly adhere to biology, the process is possible, so the strict answer to your question is: Yes, it is biologically plausible. However, if we stick to how life as we know it functions, what you describe makes no sense for the following reasons:

If your creatures are mammals, it would be much easier to be viviparous, as it works well for 2/3 of all warm-blooded creatures. In fact, humans are particularly bad at giving birth; if you look at the offspring of most mammals, they are capable of walking a few hours after birth, but primates, especially humans, are born less developed, primarily in the hips. That's why it takes about 1 year for babies to learn to walk, but that's not a problem because most primates are social animals.

Eggs give birth to quite mature offspring in general, unless you're a kiwi, you don't have problems with egg size, so there isn't such a marked limit to have to do something like what you describe. What you describe would, in any case, be a marsupial, and a pretty bad one at surviving, by the way.

If all creatures are similar, it's because the design works. If marsupials and monotremes are exceptions, it's because their design is not evolutionarily competent; otherwise, convergent evolution would cause there to be more of them. Monotremes like the platypus, one of the only two mammals that lay eggs, are born almost fully functional, just a smaller version of an adult platypus (I've included some images for you to compare). On the other hand, marsupials have internal gestation for a couple of weeks, and then the embryo is born and develops for several months in the female's pouch (I've also included photos for comparison). I think just by looking at the images, you'll notice the difference in development. A baby kangaroo, also known as a joey, is not capable of surviving outside the pouch for more than 2 hours

The platypus offspring, called puggles, are born blind and hairless, but they become semi-independent after a few days, not unlike a bird.

Finally, I'll describe how the reproduction of your species would actually be: Fertilization occurs, and a layer of collagen begins to form around a placenta containing the embryo. Five or perhaps seven weeks later, the female lays an egg that requires minimal care (e.g., burying it, covering it with straw, or anything else to prevent it from cooling in the environment; in a more advanced species, they would simply place it in a crib covered with a blanket). Eight or nine months later, a baby is born who, as they didn't have to come out of narrow spaces, already has fairly developed bones, allowing them to walk after a few weeks. As I said before, what you had previously described had all the disadvantages of oviparous and marsupials.

I hope this answer has been helpful to you.

Answer 2

check if this conclusion is at least plausible.

Since it's aliens anything can happen, but this scenario is unlikely because you're positing too many cultural adaptations to a core biological need.

Needing the community isn't something that would evolve. Creatures that can not survive and have offspring on their own if need be don't make sense in nature.

Answer 3

Almost everything fails science-based

The most "realistic" alien creations are nothing more than fanciful imaginings. We have one data point: Earth. Everything else is a guess — and not even a particularly educated guess since there's nothing we can use to prove the "education" part of the guess was right. Phrenology was an educated guess.

Having said all that, let's look at your list.

Female gets fertilized by male's "whiptail".

Judgement: unrealistic.

A quick study of birds and reptiles will demonstrate that they mate by rubbing orifices together. It can be quite an acrobatic show (I used to breed birds). But the point here is that you need two orifices: one that ejects sperm and one that collects it and moves it to the egg. (If there are biological outliers to that statement, please point them out in comments! That would be good info for the OP.)

On the other hand, I also once kept iguanas. Lovely creatures. Fun to watch chase the cats around. Not so much fun prying away from the top of the drapes. That whiptail starts off as muscle and bone but it ends as basically skin-covered bone. It serves a few purposes, but breeding ain't one of them. It would be very impractical (unless you didn't describe what you meant by this claim).

Community takes care of female while she is carrying, including feeding her and she will need all that food.

Judgement: realistic.

Assuming that there aren't examples in terrestrial nature of communal caring of breeding females (I haven't take the time to research any — but I'd be a bit surprised not to find one), I can nevertheless easily suspend my disbelief for the idea.

While inside mother, egg absorbs nutrients and other stuff like antimicrobial chemicals.

Judgement: realistic.

This is basically what happens in real life. So you're good to go.

When time comes, female pushes out snot in thick leather (sexy, I know).

Judgement: kinda maybe realistic.

What do you mean by "thick leather?" Cockroach eggs are made up of a hard, thick leathery material. This one doesn't really work for me. The female isn't bearing an egg, she's bearing a sack. Can we find an example of a bird that lays a "thick leather" egg? Even if it hardens after laying?

Update: Based on a comment by @John, I found the following, "Most reptiles lay eggs with soft, leathery shells, but minerals in the shells can make them harder. Crocodilians and some kinds of turtles lay eggs with tough shells—more like a bird's egg." (Source) Based on this I've changed this judgement.

This little snotty is taken care by community, including keeping it watered and warmed.

Judgement: kinda unrealistic

While I can suspend my disbelief for caring for the mother, and I know there are examples in nature of kinda communally caring for infants (sea lions, if I recall correctly), I don't believe there is an example where the mother becomes disconnected from caring for the child — and this statement kinda reads that way. There's a difference between "communal help" and "communal responsibility." I could believe "communal help." I can't believe "communal responsibility."

Snotty inside is practically speaking brainless ectotherm for early phases of deveploment.

Judgement: unrealistic

Brains are needed to control things like hearts, lungs, muscles, etc. Only in the earliest stages of gestation while cell division is still the predominant characteristic of gestation is there no brain. Unless by "brainless" you mean "can't care for themselves" or "can't think," in which case this is totally realistic because that's what happens in real life.

Shorty before hatching from thinning leather shell, their brains began to deveploment little.

Judgement: unrealistic

At least in the way you mean it, it's unrealistic. All creature's brains develop after birth. Most animals are ready to functionally participate after birth — but the brain is still forming. Humans are totally incapable of functioning independently after birth, so ours has the most development to go. However, this statement is built on the previous "brainless" statement and that's just not how nature as we understand it works.

Once little snotty hatches, they practically speaking have pea soup inside their skulls.

Judgement: unrealistic

This is just a restatement of the previous "brainless" condition.

Community takes care of snotty the moron who can't even maintain their body temperature.

Judgement: kinda unrealistic

This is a restatement of the previous "taken care of by community" condition.

As time passes, this kid grows, literally gets some brain and becomes able to main their body temperature like good endotherm should be.

Judgement: realistic

This is how life works. If we ignore your "brainless" condition.

Conclusion

Why is it important for an alien species to be science-based? If it is important, then you're required to use examples from nature to stitch together your frankenstein alien. You can't just invent things and hope they line up with science.

It's actually really cool to use science (in the form of pieces or attributes of actual creatures) to model an alien species. This gives the species the look and feel of a plausible creation without worrying about just how plausible it really is (it isn't...).

Answer 4

You may actually have had a very good idea there.

One reason mammals are so successful is that a mother can really put a lot of energy into their offspring before giving birth, and she can do that over a long time as well. Birds and reptiles have to put in all the calories needed for the fetus to develop before birth in one go... Imagine if an elephant, with a pregnancy time of over two years, had to do that!

Let's see how that would go if humans were to lay eggs, while maintaining how healthy babies are born. In general, women's caloric needs increase by a few hundred calories per day when pregnant. According to medlineplus.gov, a site from the US National Institutes of Health

Pregnant women need about 300 extra calories a day.

Of course this is not constant. The page elaborates on how it is less in the beginning and more by the end of a pregnancy. Still, for a 40 weeks term, that is 84,000 calories.

For comparison, an ostrich egg - which is huge - contains only 2,000 calories.

In other words, it takes 42x more energy to turn a single cell into a human baby than it takes to turn a single cell into an ostrich chick.

Now I don't know how much og that budget goes into making the brain, but I've read the reason we are the most brainy primates is because, among other reasons, our species has easier access to calories. One way or the other, by making your species smaller and "brainless" at birth, you drastically reduce the caloric budget needed to go from a cell to a baby, making egg laying more viable.

On top of that, if the egg is not impermeable, then it can be fed externally. This brings a lot of problems related to things like infections but you alread have that covered. On the other hand, it does allow you to feed the egg somehow, making the whole thing more like an external pregnancy and thus even more viable from an energy cost perspective.

Answer 5

Most of these are believable for an alien.

there is no evolutionary reason most of these could not evolve there is two exceptions however.

Once little snotty hatches, they practically speaking have pea soup inside their skulls.

this is just impossible, it need a brain, it has to regulate breathing, heartrate, hormones, digestion an a hundred other things. They need the basic parts of the brain to be organized and functioning, they can be mentally vegetables, but they need much of the brain. to compare to our brains, the brain stem and parts of the limbic system need to be functioning. much of the cerebellum and the sensory areas need to be there even if not well organized.

Community takes care of female while she is carrying, including feeding her and she will need all that food.

This is common enough in social species. Although All the food is not going to work if you mean all the communities food, since the snotty are so underdeveloped the caloric needs of the mother should be small. They can't be both super underdeveloped/slow developing AND require massive amounts of calories. A human fetus does not even require the same caloric need of a single extra adult. If your community can't feed the mother and themselves they starved to death during the first lean year even without any pregnancies.

Other considerations

Female gets fertilized by male's "whiptail".

fine, there are a huge variety of things used as reproductive organs, the penis of a human and a bird are not even the same organ.

While inside mother, egg absorbs nutrients and other stuff like antimicrobial chemicals. When the time comes, the female pushes out snot in thick leather (sexy, I know).

As others have mentioned this is just how eggs work.

This little snotty is taken care by the community, including keeping it watered and warmed.

this is not a problem many rodents do something similar, albeit with pups not eggs, they even share nursing. Complex reproductive cycles are not uncommon.

Snotty inside is practically a speaking brainless ectotherm for early phases of development.

the brainless part is the only problem, otherwise this is a good description of how eggs work. thermoregulation is often very poor to nonexistent in developing organisms, they need thermal stability, but not necessarily to self regulate it.

Shorty before hatching from thinning leather shell, their brains began to develop a little.

"a little" is the problem it is very vague, they need the basic parts of the brain by this stage there is just too much to regulate. they don't need to be thinking or conscious but they do need to start connecting all the nerves as the tissue of the body grows, meaning most of the brain needs to be there at this stage, even if most of it is not well organized at this stage. A lot of it does need to be organized and functioning, again they can be mentally vegetables, but they need much of the brain.

Once snotty is a bit more grown and less of a moron, mother with regained strength would take care of them onwards (Forgot to add this part).

As long as this is temporary this is fine. If care is needed parental care is just too big of a evolutionary advantage to not happen. But having a recovery time could evolve in a highly social species, just keep it to a believable span of time, a few weeks or months at most.

Answer 6

Some real world animals to consider

Consider that really large dinosaurs existed. Note that egg size did not scale proportional to the larges adult sizes. There is in practice a max egg size.

Consider that marsupials such as kangaroos at birth are really undeveloped, yet grow to be functional adults.

Some changes to proposed

So in my opinion having egg size about half a liter or so would be reasonable. Since there will be large amount of post hatching development time no matter what, might as well have an egg size that doesn't have huge resource demand. Also if times are tough and an egg is produced don't want to have the cost too much to abandon. Ie no multi liter eggs.

This also means that while producing eggs a potential mother does not need much if any additional support. Egg production could occur when food intake sufficient. What is done with the unfertilized or the fertilized but unwanted eggs would be culture specific.

Incubation time of 6 to 8 weeks would be reasonable. Time scales close to what their ancestors had but somewhat longer.

Hatched

After hatching there are two major avian scenarios that I am aware of on Earth. Mostly ignoring the various other species strategies.

Chicken style:

Upon hatching chicks are quickly mobile, but dependent on mother for warmth and protection, mother guides off spring to food, water etc.

Song bird style:

Upon hatching chicks are barley mobile,little more then mouth and digestive system, parents find and stuff food into the open mouths.

Either way post hatching would be where community/family support would help ensure success of offspring. That being said, it should be such that one or two parents are able to raise offspring. If the parents couldn't raise offspring without support, how would this species ancestors have been able to survive to the time of the story?

So to put it together

• Females produce eggs when sufficiently fed.
• Eggs relatively small compared to live birth, eliminating need for support.
• Eggs may or may not be fertilized, depending on activities.
• Once a female gets broody that's when she starts incubating eggs, her constant body warm triggers development of the egg.
• One hatched parents, optionally community make sure off spring fed and protected.
• As offspring grow, so does it's brain, skull and mental abilities.

Conclusion

While the outline in the question is plausible, I feel the egg specific portions should be modeled closer to how known egg layers operate such as chickens. Major thing is having a system such that the females don't need support, it's more biologically plausible. Community support of hatchlings should enable better outcomes with higher reliability, but primary care would still be the parent or parents.