Some species that reproduce sexually, don't actually have sex as such. Instead the female might lay soft scaled eggs, which the male then fertilizes extrenally.

I want to know what a society of an intelligent species that lays lots of eggs and fertilizes those externally might look like. Lets say that in their original habitat, the climate was such that they could (and did) lay and fertilize eggs and then essentially forget about those eggs. (Perhaps after burrying them)

For this question, you may assume that this species is otherwise similar to humans (unless where differences are necessary) and have access to technology at least as advanced as our current technology.

Some topics an answer should definitely touch upon are:

  • Parentage
  • How/why did this species evolve to be so intelligent?
  • Measures (not) taken to increase chances of survival for unborn individuals.
  • 1
    $\begingroup$ Related: worldbuilding.stackexchange.com/questions/542/… $\endgroup$
    – Tim B
    Commented Oct 9, 2014 at 14:14
  • $\begingroup$ This seems to be a very broad question to me. $\endgroup$
    – bowlturner
    Commented Oct 9, 2014 at 14:26
  • 3
    $\begingroup$ @TimB external fertiliation does not necessitate non-maternal characteristics or many offspring. It may imply them, however, so you comment is not invalid. $\endgroup$
    – kaine
    Commented Oct 9, 2014 at 15:12
  • $\begingroup$ Seahorses fit the premise of your question if we remove the part where they have to forget about the young. $\endgroup$
    – Black
    Commented Oct 9, 2014 at 20:30

4 Answers 4


This is very broad, so I'll just touch on a few of the more significant aspects you bring up.

  • Parentage

It's quite possible that individuals wouldn't even know who their parents were. At least not in the biological sense. The most likely consequence of this is a sense of collectivism, at least in regards to the responsibilities we associate with parents -- the younglings would be considered to collectively be the children of the spawning generation, who in turn would collectively be considered to be responsible for them.

That said, it's also possible that a given brood would be known to come from a particular set of eggs, which in turn would be known to have been laid by a given mother. This could give rise to maternal interactions. Further, depending on the exact mechanisms and circumstances of fertilization (e.g. isolated pools fertilized by only a single male), the father may be known as well (or even instead!). So you could have the same (or at least similar) concept of a family as we do; I think it more likely, though, that you'd have the collective version (previous paragraph) instead.

  • Intelligence

A concept of responsibility for the younglings would be a necessary foundation for intelligence (barring some pseudo-science mumbo jumbo about genetic memory being passed on to the offspring, of course), because ultimately someone has to teach them. In this case, you'd have a society where the elders collectively teach their skills and knowledge to the younglings. This would include imparting social norms, religious beliefs, etc. to them, not merely the "three Rs" ("Reading, wRiting, and aRithmetic") taught in schools.

As a result you'd have a stronger sense of community and of belonging to a group than we do, but this of course does not in any way preclude individuals being individuals -- they'd just tend to view themselves as individuals within the group. Most likely you'd still have social outcasts -- including those who distance themselves on their own -- but equally likely the elder generation would be more upset and concerned about this than our own is -- they would be less likely to just say, "Oh, that's just how he/she is," and instead try harder to bring them into the fold and make them a part of society.

  • Survival of Unborn

Here, I think the most likely techniques are those that nature evolves. The first is simply large broods -- if each mother lays a thousand eggs, then a predator eating or destroying 98% of them still leaves 20 healthy younglings hatching, more than enough for solid population growth. The freshly-hatched younglings would likely stay in the pool for a while, vulnerable to predators further thinning their numbers, but with so many examples right here on earth showing that raw numbers is a successful strategy I don't see any reason to improve upon this.

That said, an intelligent species that values their young would very likely develop means of protecting their young, including (for example) artificial breeding pools protected from predators.

Another common survival technique is for one or the other of the parents to stand guard over the eggs until they hatch. I honestly find this a more likely species to advance into intelligence, because it already demonstrates strong parenting instincts necessary for an intelligent species to progress. This also more naturally flows into more-developed means of protecting the eggs and fresh hatchlings.

That's not to say that a society of intelligent beings couldn't evolve and still leave their eggs and hatchlings unprotected. They may in fact view such as an important part of growing up, of making society as a whole stronger by ensuring that only those strong enough to survive and contribute do so. (For a real-life example of something similar, take a look at the ancient Spartans -- though they've been largely embellished and all but fictionalized, there's still some grains of truth at the heart of it.)

Really, how they ensure the survival of their unborn is going to depend entirely upon what type of society they are and how they evolved, which is pretty much entirely up to you.

  • $\begingroup$ I think your assesment of the sense of community is wrong. It seems that humans lived in a similar society, where each of the children were taken care of by the elders and mothers, rather than their parents. This only changed with the introduction of agriculture and a sedentary life-style. Oh, and of course, the schools being primarily a tool of the progressively bigger governments. Since this happened with humans, I don't see why there's a reason to assume that it wouldn't happen with an exfert species - they'd simply house their eggs and younglings in their houses, just like we do. $\endgroup$
    – Luaan
    Commented Oct 10, 2014 at 8:26
  • 1
    $\begingroup$ @Luaan That's certainly possible, as I mentioned. However if their culture evolves in a way that never considers it "inhumane" for eggs and fresh hatchlings to be left vulnerable -- a very common instinct in exfert species that is not found in live-birth species like humans -- then they will follow a decidedly different path than we did. $\endgroup$
    – Kromey
    Commented Oct 10, 2014 at 16:05
  • 2
    $\begingroup$ IIRC, large broods are called r-strategy (vs. k-strategy for humans and elephants) $\endgroup$
    – user4239
    Commented Oct 11, 2014 at 7:03

Well external fertilization tends to require large numbers of both eggs and sperm and a medium that is conducive to the two joining in a timely manor. Water is an effective medium so I would expect the species to be somewhat amphibious, at least for the 'breeding season' (assuming land dwellers) could be Piscine as well. Living underwater would open a whole different kind of society at least for possibilities.

Since it takes a lot of energy to produce a clutch of eggs, I would expect the females to have an actual 'breading season'. As such I would think that many things that lead to human relationship problems would not exist (infidelity being a big one), but others would take their place.

I think for a species to advance, learning needs to be passed from one generation to the next and the more information that can be handed down the faster advancement will happen. So for this there will need to be some kind of generational attachment to pass the knowledge down. I would expect a bit of culling most likely by the parents as things progress, starting with eggs that appear to be having problems, disfigurement etc. After hatching the sickly and weak would go. As the species continues down it's path I would expect smaller and smaller clutches as the parents take more and more of a role in ensuring their survival until breeding age.

Instead of the parents culling, if the young stayed in the water (at least for a development stage or two) then they could be a 'catch and release' type of deal, parents just ensure they make it to hatching, then they swim away and fend for themselves, once they have reached a certain stage in their life (those that survive) they try to rejoin with the adult society and then really begin to 'learn'.

  • $\begingroup$ Unless it's like in-vitro, single egg being bathed/injected in sperm is plausible. $\endgroup$ Commented Oct 10, 2014 at 9:01
  • $\begingroup$ yes, and your point being? $\endgroup$
    – bowlturner
    Commented Oct 10, 2014 at 13:09
  • $\begingroup$ that it's not always a large clutch, but instead just lay a egg ready for fertilization periodically (maybe triggered by current relationship) $\endgroup$ Commented Oct 10, 2014 at 13:15
  • 1
    $\begingroup$ Do you mean that it doesn't need to be large number of eggs? Do you have any examples that currently exist that way? Because that was what I was basing the answer on. All of the ones I found are many eggs, because for external fertilization that happens to be the most effective way. I also put in there that I thought the clutches of eggs would likely diminish in size as the species advanced and survival rates increased. Just not so bluntly. $\endgroup$
    – bowlturner
    Commented Oct 10, 2014 at 13:20

Always stuck on questions like this because I have difficulties seeing the onset of intelligence to a human degree.

The human brain has a 'survival' brain (sometimes referred to as 'reptilian brain') that's distinct from our neocortex. It's the fight or flight center that can and will over-ride a normally rational persons behavior (extreme phobia's come from this 'survival' brain overpowering the rational mind, allowing for very irrational behavior when the object of the phobia is nearby even if the majority of us remain rational in the presence of the object of that phobia. Ever meet someone that is so afraid of cat's that the presence of one of these cute creatures causes the same reaction as someone would have in the middle of a battle in a war?). For a rational creation to emerge, you need the neocortex to be far more useful than the reptilian brain.

Our human upbringing is what allows our rational mind to dominate over the survival brain. We are not rational creatures by birth, it comes with development which is ultimately defined by the environment it grows up in. Had there been a trigger, the reptilian brain fully overrides the neocortex (fight or flight). This trigger can remain...an early childhood trauma can set a situation where if that same event that triggered it in the past occurs now, you'll be in the same flight or fight mindset regardless of if the situation is dangerous to your survival now. Our phobia of cats person above could have had a horribly traumatic event in their early lives that still persists today despite the cat posing no real danger to them now.

If put into a fight or flight scenario at a young age, this survival brain begins to dominate and not allow the development of the neocortex. The problem with egg clutches is you have a species that is born into a survival situation and youth with stronger survival instincts would be the ones to survive (a threat to their young life occurs, a being that enters fight/flight mode instantly would survive at a much greater ratio than one that tries to think about it first...thought is sadly counter intuitive to survival). This means those that survive will be strong instinctual beings rather than intellectual ones.

At the very least, every one of these creatures will have hit a survival scenario early in it's youth...in humans that results in phobia's, psychosis's, and a wide array of mental disorders. Could a functional society ever develop from a society where the majority of adults have massive psychosis issues and quite possibly paranoia?

  • $\begingroup$ This is an interesting argument - but the thing is you're applying human values and consequences to an alien being. Clearly they would have a strong evolutionary pressure for the adults to not have too much in the way of lasting trauma from their time before adulthood. $\endgroup$
    – Tim B
    Commented Oct 9, 2014 at 22:20
  • $\begingroup$ Imagine that a culture would form, where some portion of a populace of a tribe would keep guard of the eggs, just like humans did with babies. External fertilization doesn't necessarily imply that you have to hide your eggs from your own species (of course, not that baby killing is exactly something underrepresented in Earthly life :D). Octopodes might be an example to learn from. $\endgroup$
    – Luaan
    Commented Oct 10, 2014 at 8:32

It's going to depend on how many eggs per clutch and how often they are laid.

Small rare clutches (single egg once a year) will be much more valuable than a dozen every week.

Also the spawning ritual itself; it can go from dropping all the eggs into the communal gene-pool to having female select a male for him to inject the individual egg with his sperm using a needle like genitalia. With the latter you will have actual parenthood while with the former it's a more communal raising of the offspring.

If the eggs are rare, some females are barren and you have an economy then you will get a black market for viable eggs.


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