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Gomar
2011-Dec-23, 02:57 PM
How do aliens give birth? Ifcourse, it's all speculation, but is it by laying eggs, like turtles, spiders, chickens, etc.
or like humans, no eggs, but baby grows inside the womb, and then female gives birth?
If aliens are intelligent mammals, then it's logical the mother would not lay eggs. Why?
Because no animals that lay eggs on Earth are intelligent. Ifcourse, dolphins and whales dont lay eggs,
but they dont use computers nor make fire.
If there are insects or birds or lizards on other planets, they might lay eggs. But I dont see how primates
would lay eggs as there is no evolutionary advantage to that. I just dont think that any intelligent species
like the alien in the 'Alien' movies might lay eggs.

Nowhere Man
2011-Dec-23, 06:55 PM
Since we don't know about any aliens, it is very likely "All of the above." Especially if you're talking about all of the aliens in the universe. They're (probably) not all little green or gray men.

Fred

Noclevername
2011-Dec-23, 08:30 PM
Since mammals, reptiles etc. are all genetic lines of development on Earth, alien life won't be mammals or reptiles, or any other Earth genotype. There may be some convergent evolution resulting in broadly similar phenotypes, but that won't have any relation to reproductive types-- sharks and dolphins are similar in shape and are both predators, but one lays eggs and one gives live birth.

Alien life might also encompass budding like a sponge, pollination like a plant, spreading spores like a mushroom, fission like bacteria, fusion of two organisms into one like an anglerfish, or some other form of reproduction not found on Earth.

Ara Pacis
2011-Dec-23, 09:01 PM
Live-birthing requires a lot of energy, mostly due to large size of the offspring at birth, but also keeping the developing fetus warm and for general locomotion and other organism activities, as well as for repairing the damage caused by live-birthing a large organism. That's energy that might be used for brainpower. There's your potential evolutionary advantage.

Gomar
2011-Dec-24, 12:36 AM
That's energy that might be used for brainpower. There's your potential
evolutionary advantage.

ok, but still the most intelligent species on Earth does not lay eggs but gives birth. Doesnt that prove something
about laying eggs? Many eggs could be layed, but only a few will survive vs. 1 baby is birthed that has a high
rate of survival. Turtles lay eggs, and then bury them and swim away. Spiders eat their babies, some birds throw
their kids out the nest. Ifcourse cows do not lay eggs, but they cant read nor write.

Noclevername
2011-Dec-24, 01:04 AM
ok, but still the most intelligent species on Earth does not lay eggs but gives birth. Doesnt that prove something
about laying eggs?

No, that's generalizing from an example of one. There are also some pretty dumb species that give live birth, and some fairly smart egg-layers.

Ara Pacis
2011-Dec-24, 01:05 AM
ok, but still the most intelligent species on Earth does not lay eggs but gives birth. Doesnt that prove something
about laying eggs? Many eggs could be layed, but only a few will survive vs. 1 baby is birthed that has a high
rate of survival. Turtles lay eggs, and then bury them and swim away. Spiders eat their babies, some birds throw
their kids out the nest. Ifcourse cows do not lay eggs, but they cant read nor write.Are you confusing correlation for causation? You've given no reason why one would conclude that intelligence and egg-laying do not go together on earth, much less an imaginary alien environment.

Githyanki
2011-Dec-24, 04:04 PM
Actually, the reproduce my attacking a face-hugger to a host and then burst of the chest a few days later.

And I'm imagine Grays clone themselves.

TJMac
2011-Dec-24, 04:27 PM
I always just assumed they did an amoeba type thing. To begin with, you have one alien, then suddenly, two somewhat smaller aliens... ;)

TJ

Perikles
2011-Dec-24, 04:40 PM
I always understood that they produced new aliens on a long conveyor belt in a factory.

And guess how they make their vehicles. :D

swampyankee
2011-Dec-24, 09:44 PM
I have to agree with the "all of the above" answer, but amend it to "and then some." Of course, given the vast variety of reproductive strategy among multi-cellular animals on Earth, the aliens may not have figured out anything new.

I don't see any particular reason why sentient ETs could not use something akin to egg-laying, or any of varieties of live birth. Considering that live birth has evolved several times -- in at least some types of sharks, some insects, some ray-finned fish, and most mammals (in two varieties) -- I'd be surprised if it doesn't show up among our ETs. On the other hand, considering how smart crows are, I'd not be too surprised if they lay eggs. I'd also not be too surprised if they do something even weirder. Of course, there's still a chance some biologist will say "hey, that's just like this family of invertebrates...."

JCoyote
2011-Dec-24, 09:59 PM
It's a big universe. So all of the above and a handful we just don't have the context to imagine.

I don't see any particular form of reproduction as potentially excluding an intelligent, sentient result. I don't see any particular fundamental reason why development toward that level of intelligence absolutely must happen inside a protected environment.

Honestly, as fundamentally important as it is to a species, I would be surprised to never find an intelligent species that uses 3 or more forms of reproduction. Many types of plants can, and while sentient species seem likely to be more K strategists, having multiple paths of reproduction is still useful even then.

One thing that is a bit surprising about mammals when I consider it, is that mammals rely on intelligence in general and tend to have complex brains. I'm surprised there doesn't seem to be a direct neural connection during gestation to basically give "up to date" environmental information to the young so they could be ready faster. It could be a powerful adaptive advantage, the only thing that seems to mitigate it is that larger mammals take enough years to grow to maturity that they have plenty of time to learn as they do. Still, I don't see any real physiological reason that sort of thing couldn't work in mammals or similar species.

Ara Pacis
2011-Dec-25, 01:06 AM
One thing that is a bit surprising about mammals when I consider it, is that mammals rely on intelligence in general and tend to have complex brains. I'm surprised there doesn't seem to be a direct neural connection during gestation to basically give "up to date" environmental information to the young so they could be ready faster. It could be a powerful adaptive advantage, the only thing that seems to mitigate it is that larger mammals take enough years to grow to maturity that they have plenty of time to learn as they do. Still, I don't see any real physiological reason that sort of thing couldn't work in mammals or similar species.Well, most evolution happens by chance and progresses from previous anatomies. Live birth is a modified form of egg-laying when it comes right down to it. Eggs that are laid had no need for neural connections to exchange information, so the chance that evolutionary descendants would spontaneously develop such a capacity is probably very low. Even if a neural connection were possible, is there any scientific data to suggest that information of that high order of complexity could even be transferred between individual minds?

Blackhole
2011-Dec-25, 06:00 AM
I am of the option that Aliens probably exist billions of times over in the Universe, and therefore it is likely that there are both ege laying and birth giving Alients, as well as Aliens that use some other method of reproduction.

JCoyote
2011-Dec-25, 12:53 PM
Eggs that are laid had no need for neural connections to exchange information, so the chance that evolutionary descendants would spontaneously develop such a capacity is probably very low. Even if a neural connection were possible, is there any scientific data to suggest that information of that high order of complexity could even be transferred between individual minds?

The existing mammalian placenta is rather complex and violates those odds of eveolutionary development already, but it did happen.

And the level of information transfer to provide advantage is not high; it simply needs to be "better than waiting for vocal and auditory processes to work it out". A full set of memories, or at least significant memories and useful skills, might be more than is really needed even if it would be ideal. But even if something like language could be a developed skill by birth, or just knowing what the best foods around look/smell/taste like could be plenty and not require much bandwidth when it has months to do the job.

Colin Robinson
2011-Dec-26, 02:53 AM
I agree there are probably a range of methods.

It is quite possible (for the sake of argument) that intelligent aliens might resemble humans to the extent that the offspring remain dependent on parental care while they are developing. And information gets passed from one generation to the next via a cultural process. But all this would be quite consistent with a bird-like life cycle, where eggs are not just laid and abandoned, but kept in a nest, and the young get fed and protected after hatching.

And what about the marsupial way of reproduction? The mother gives birth when the offspring is still tiny, but after that there is a stage where it gets protected in the pouch. Intelligent aliens who reproduced in this way would not face the human mother's problem of getting a large-headed baby through a narrow birth canal, because most of the brain growth could happen in the pouch stage.

Marsupials in Australia and New Guinea filled many of the niches occupied by placental mammals elsewhere. Kangaroos are comparable to deer, the extinct thylacine to a wolf.

True, there are no marsupials here on Earth with human-like intelligence. But on another world, is there any reason why an arboreal animal with a pouch couldn't develop into a pouched monkey-like creature, and then a pouched humanoid?

JCoyote
2011-Dec-26, 04:34 AM
It could be fun to design alien creatures based on randomly rolling dies on various animal features, and then figure out the sort of environment they'd need later. Pretty close to how evolution does it.

Ara Pacis
2011-Dec-26, 07:08 AM
And the level of information transfer to provide advantage is not high; it simply needs to be "better than waiting for vocal and auditory processes to work it out". A full set of memories, or at least significant memories and useful skills, might be more than is really needed even if it would be ideal. But even if something like language could be a developed skill by birth, or just knowing what the best foods around look/smell/taste like could be plenty and not require much bandwidth when it has months to do the job.It really depends on what you mean by "'up to date' environmental information". Food preferences are often hard-coded with instinct based on chemical receptors tied to certain areas of the brain. Temperature and other physical variables like pressure are simple but still require being hard-coded to the brain, but that might be plausible in a earth-like physiology. However, having an understanding of the larger environment beyond simple already-encoded sensory nerves would require a brain to already have concepts and encoding capability before birth and some method of receiving those higher concepts from the mother's brain. Maybe if an alien reproduced via fission and the brain was duplicated in part or its entirety then that might work, but it's not really the same thing because it's a replication of an organism already existing in the world, not a new lifeform that has yet to experience it directly.

JCoyote
2011-Dec-26, 10:35 AM
Replication of portions of the maternal brain is exactly what I was talking about. Sort of like cloning a hard drive. The only question is which portions and how deeply ingrained the stuff that's replicated is. There is no evolutionary preference toward individualism for an organism. And indeed, a species like that might behave more individualistically because new generations might feel more desire to establish differences or try new things.

But let's be blunt here, there is no need for "concepts" to be transferred. That is showing respect to our own abstract thinking and imagines it more like translating between languages or talking between people, but it would not likely work like that. My SATA cable has no comprehension or interpretation of the data it moves from one hard drive onto the next. It doesn't need to. The process could be entirely subconscious, with gooey gray matter a better analogy would be providing a mold for the material to grow into.

For an omnivore like humans, food preferences aren't very hard coded, and it's better that they aren't. European people avoided eating potatoes and tomatoes at points because of various fears. For mobile omnivores, waiting for dna hard coding to do the job is waiting too long.

aquitaine
2011-Dec-26, 05:10 PM
Since mammals, reptiles etc. are all genetic lines of development on Earth, alien life won't be mammals or reptiles, or any other Earth genotype. There may be some convergent evolution resulting in broadly similar phenotypes, but that won't have any relation to reproductive types-- sharks and dolphins are similar in shape and are both predators, but one lays eggs and one gives live birth.

Alien life might also encompass budding like a sponge, pollination like a plant, spreading spores like a mushroom, fission like bacteria, fusion of two organisms into one like an anglerfish, or some other form of reproduction not found on Earth.

Just to nitpick, most species of sharks do not lay eggs either, but rather have live births.

Ara Pacis
2011-Dec-26, 06:57 PM
Replication of portions of the maternal brain is exactly what I was talking about. Sort of like cloning a hard drive. The only question is which portions and how deeply ingrained the stuff that's replicated is. There is no evolutionary preference toward individualism for an organism. And indeed, a species like that might behave more individualistically because new generations might feel more desire to establish differences or try new things.

But let's be blunt here, there is no need for "concepts" to be transferred. That is showing respect to our own abstract thinking and imagines it more like translating between languages or talking between people, but it would not likely work like that. My SATA cable has no comprehension or interpretation of the data it moves from one hard drive onto the next. It doesn't need to. The process could be entirely subconscious, with gooey gray matter a better analogy would be providing a mold for the material to grow into.On the contrary, even your computer analogy requires abstractions. Transferring data is only doable if there is a formatted system ready to receive and make sense of the input. Even if you're cloning the information you need to keep in mind that there are various layers to network communications (http://en.wikipedia.org/wiki/OSI_model) which might need to be replicated in biology. This even assumes information can be "transferred" anyways. Animal brains on earth keep memories through connections with a network of nerve cells, not binary bits, so instead of transferring a memory as some sort of file, it might be more akin to replicating the experience virtually so that it can be recorded (encoded) at the destination brain. Of course, you're free to posit some sort of alien biology that can do this or can store memories in some sort of file format, but then it's up to you do suggest how that might work, and maybe how something like that might evolve.


For an omnivore like humans, food preferences aren't very hard coded, and it's better that they aren't. European people avoided eating potatoes and tomatoes at points because of various fears. For mobile omnivores, waiting for dna hard coding to do the job is waiting too long.Actually, this might be easier to do experientially if the fetus can experience chemical signals in the blood or through nerves and can experience pleasure, excitement and pain from blood-carried neuro-chemistry (e.g. endorphins, adrenalin).

Noclevername
2011-Dec-26, 08:36 PM
Just to nitpick, most species of sharks do not lay eggs either, but rather have live births.

:doh: Nitpick accepted. I supose for completeness I should point out the monotremes as well, the infamous egg-laying mammals.

vasiln
2011-Dec-30, 10:44 PM
There are a lot of competing theories for what sort of factors lead to greater intelligence. It's probably not true that method of birth is totally irrelevant to technological development. However, as has been said, it's pretty tough to be sure when you're generalizing from a single example.

Octopuses are considered by some to be the most intelligent non-human species on Earth, and they're egg-layers.

However, one popular theory of human intelligence says that it developed through a process of neoteny-- that is, through increasing juvenilization of humans. (It's a nice theory, because it explains our hairlessness, our gigantic heads, and our creativity in one fell swoop.) The idea behind that is maybe roughly the following:

1) Animals that engage in learning devote their early life to learning, which is a sort of play-- they try things out, sometimes stupid things, and see what works.

2) Spending a long time as a juvenile means there's a long time during which to play, which means more things get tried out. That includes things like throwing sticks, hitting rocks with other rocks, etcetera.

3) Possessing childlike qualities throughout one's lifetime leads to spectacular failures (ye olde Darwin awards) and spectacular successes ("I wonder what things would be like if time wasn't absolute like we all assume it is...").

Now, there are certain things that go hand-in-hand with neoteny. One of the things involved is a very long childhood (sort of the definition, duh). But long childhoods are troublesome, because children are very vulnerable; and as more knowledge is gained through learning and less through instinct, it's necessary for parents to spend more time teaching them. This suggests a certain reproductive strategy ("K-strategy") which is to have few offspring, but value them highly, and guard them closely. (The opposite of this is r-selection, and says, make lots of babies/eggs, and maybe some of them will survive.) Live birth is related to this, because when you're gestating few eggs, you might as well carry them around with you-- it's a lot safer than leaving them in the nest-- but if you have lots of eggs, that's more difficult. If you have very few babies, or they're very small, you might carry them around with you for a while after birth, like a kangaroo, or a human.

The factors that affect evolution on Earth are likely to affect evolution on other planets. There's no evolution without scarcity, without competition-- there's no intelligence without predators that want to eat your babies, so you need a strategy to protect them. Some variant of live birth is likely for technological aliens (consider other possibilities, like babies budding off your stomach, which is essentially live birth, or carrying eggs around in your mouth, which is again strategically similar to live birth) is likely, but not guaranteed. But of course, there are still smart octopuses, and like I said, there are competing hypotheses to explain the development of human intelligence.

Cloning information-- getting your parent's 'mind'-- occurs quite a bit here on Earth; we call it instinct. It's not associated with technological development. It seems that 'knowing' something prevents learning something. Evolution leads to local maxima. To get to more global maxima, you gotta add some craziness to get through the pits. But it's not quite an either/or situation. The idea that grammar is hardwired in-- that is, transferred from our parents-- is pretty popular. The problem is just that if you transfer too much information from parent to child, then the child tends to use the transferred information rather than exploring the environment. Not that that's not a successful strategy, plenty of critters do it, all critters do it to one extent or another, but it's not a strategy that leads to complicated technology.

mutleyeng
2012-Apr-07, 07:14 PM
interesting post Vasiln.
the extended childhood of humans is a consequence of brain size i thought. a human baby must be born with a significantly under developed brain literally so that its head can fit through the hole.

an interesting point to remember when we hypothesise about relative intelligence, there will always be physical limitations.

NoOne
2012-Apr-08, 08:02 PM
why have male and female...to me thats rather odd and not efficient. a species really only needs one type to produce copies of itself.

swampyankee
2012-Apr-09, 10:07 AM
why have male and female...to me thats rather odd and not efficient. a species really only needs one type to produce copies of itself.

There are numerous biology professors who have been trying to answer the question "why did sex evolve?" as it seems less efficient than asexual reproduction. One of the answers is "parasite resistance."

astromark
2012-Apr-09, 10:40 AM
It's a interesting subject that in my view has no actual answer available to us yet..

Not that there was ever a question..

We. The inhabitants of planet Earth have no other case to study yet..

We can not say one method of reproduction is the end game.. We are still part of a evolving species.

To think any 'other' world would follow or be similar is in my view not scientific..

We do not have all or enough information to be conclusive.. but still interesting..

My over ridding thought is this.. Whatever we find. It will be different. Because it can be.

Ara Pacis
2012-Apr-12, 07:49 PM
There are numerous biology professors who have been trying to answer the question "why did sex evolve?" as it seems less efficient than asexual reproduction. One of the answers is "parasite resistance."Don't forget bacteria and plasmids. Organisms have evolved a process to share DNA, and perhaps that happened long before multi-celled organisms evolved. Add to this research that shows bacteria are communicating with each other using chemical messages making them act like unitary multi-cell organisms and it may seem odd that more multi-cell organisms don't use sexual reproduction.

iloveouterspace
2012-May-01, 12:49 AM
I'm always wondering if there is other life forms out there in space and on another planet that supports life besides humans such as creatures that have two legs like us and that they have black slanted eyes and big heads and that they have more improved and upgraded weapons and technology.

iloveouterspace
2012-May-01, 12:56 AM
I'm always wondering if there is other life forms out there in space and on another planet that supports life besides humans such as creatures that have two legs like us and that they have black slanted eyes and big heads and that they have more improved and upgraded weapons and technology.

flynniv
2012-Jun-20, 12:32 AM
Just to nitpick, most species of sharks do not lay eggs either, but rather have live births.

I think that even then, the sharks are birthed from eggs, just that the eggs aren't 'laid' but carried inside the mother shark until they hatch (tho I could be wrong).

Can I ask what the definition is of "intelligent" life? Ravens use tools - heck, some of them use us! I remember a thing about some crows or ravens (in England, I believe) that were dropping seeds or nuts onto a crosswalk - the crosswalk, mind you, not the middle of the road - and waiting for the light to change. The cars would drive over them and then the birds would wait for the light to change again before they went down to pick through their now-opened lunch.

Sure, the crows of the world may not have a civilization but that's some pretty high-functioning brain power, and I can definitely imagine an alien that evolved from something similar.

Jens
2012-Jun-21, 08:23 AM
Ifcourse cows do not lay eggs, but they cant read nor write.

I really don't understand. Why are you bringing up cows in a negative context? I thought your point was that egg-layers are less intelligent. . .

BigDon
2012-Jun-29, 11:16 PM
The main thing an organism has to figure out first, before live birth can insue, is a genetic method to determine gender.

That just came out in a recent paper.

Pythons give live birth and are very "basic" intellect-wise. Possums give live birth and qualify as pea-turkey stupid.*

I've seen possums walk face first into flower pots. Only 60% the cranial capacity of a rodent the same size. That's reptile stupid.

Gomar, the main thing you should do in my opinion, is get thee to wiki and look up the various forms of vivipary that creatures of Earth use, with the two main variations. Even hunted them down for you.:

http://en.wikipedia.org/wiki/Vivipary

http://en.wikipedia.org/wiki/Oviparity

http://en.wikipedia.org/wiki/Ovovivipary



*As explained by my parents, who were both farm raised in rural Oregon, certain pea vines were neurologically toxic to turkeys, who eat them anyway and suffer brain damage as a result.

Domestic turkeys are rather bird-brained to begin with, so retarded, brain damaged turkeys I imagine are just sad to behold.

primummobile
2012-Jun-30, 08:01 PM
why have male and female...to me thats rather odd and not efficient. a species really only needs one type to produce copies of itself.

It's not very efficient if you are only considering the number of offspring. But sexual reproduction does improve the fitness of the progeny, especially over many generations.

Sexual reproduction is also better than asexual reproduction at repairing any genetic damage to that line. Diploids (organisms having two sets of chromosomes) have a much better chance of eliminating damaged genes because chances are that only one of the two genes will be damaged. An asexually reproducing organism passes all genes to its offspring, damaged or not. The only way that damage is going to be repaired if for that damaged gene to undergo another mutation down the line. That is far less likely to happen than the method of gene repair employed by sexually reproducing organisms.

Almost every multicellular organism on the planet reproduces sexually. That alone is evidence of the usefullness of sexual reproduction.

What could or should happen on alien worlds is all just conjecture. I wouldn't go so far as to say that something resembling sexual reproduction hasn't evolved elsewhere in the universe. But I don't think that we can really do anything more than guess, and since we only have one confirmed sample to work with, those guesses are going to be pretty wild and have very little basis in reality.

BigDon
2012-Jul-03, 04:04 PM
Hi Prim, welcome aboard.

Basically one gender isn't enough and three is too complicated.

BigDon
2012-Jul-03, 04:21 PM
Now in science fiction, one of the races in the Planet of Adventure series was the Dirdir. A bipedal, cheetah sized space faring race of felinoids. They had 23 genders, any combination of three being needed to produce offspring. (And if I recall correctly seven combinations were forbidden due to religeous reasons.)

The Dirdir also openly enjoyed hunting human children for sport. Legally purchased ones mind you, and only on their hunting reserves. They aren't savages afterall and humans produce so many of them. Six to ten year olds especially. At that age they are old enough to understand what was happening and therefore "audibly stimulate the Dirdir's hunting instincts" when they finally close in on them, while still being small enough to take down with just teeth and claws.

Yeah, the main character didn't think very highly of them.

He thought even less of the humans who mimicked them.

Ara Pacis
2012-Jul-03, 06:50 PM
When you say gender, do you mean genetic sex identification or do you mean social role identification?