There are so many types of being upon the planet, the means by which they breed have not only altered, but become more varied. For the most part, creatures reproduce the same way humans have always done so. Yet some have their own way. Beings will do whatever works in order to survive. This will often limit interbreeding, and that has other problems as well, but it still happens.
An important topic to initially deal with is who can interbreed with who. Humans can breed with each other, obviously, but also mutants, who are simply altered humans. This has led to many interesting mixes, as has breeding between types of mutants – some of them are improved beings created scientifically, others are naturally misshapen due to various pollution. Machines cannot interbreed with anything else. Cyborgs can make more of their own as living beings. The cybernetic aspects to a new creation will be added over time. As for monsters, not only is it the case that humans and mutants cannot breed with them, but the types of the supernatural race don’t mix either.
To elaborate on this point, harbingers cannot breed with brutes, nor devil-beasts with gleaners, etc. There are many practical reasons, in terms of varying sizes and differing ways of reproduction. However, some could, and there are certain theories about why it doesn’t work. Many will claim monsters cannot breed with humans or mutants because they were originally from another plane of existence. They will add that monsters may be deemed a collective by humans, yet they are very different creatures, so there is no reason why they should be expected to be able to interbreed.
But there is a tale among many that the humans made a wish early on. They saw these new creatures and feared not only what they were doing, but what they could do to transform the human race. They feared being replaced by hybrids. They also feared hybrids of the monsters themselves – new and improved versions of harbingers, vandals and writhers, for example. So someone or someones used a magi and made a wish that monsters couldn’t breed with others. Only their own. Another thing to add to this is that dragons seemed not to be able to reproduce at all. Being creatures much more attuned with magic and the Shadow World, they found they couldn’t bring new life into this world. That is, apart from the infamous Havoc, half human, half dragon warrior of legend. Perhaps this is a major part of why the dragons returned to the Shadow World.
It has to also be noted that monsters have different ways of reproducing. For instance, gleaners and denizens lay eggs. The difference between them is a gleaner queen will lay many, whereas a denizen will lay one egg and raise it alone, imprinting all the knowledge and skills available. Writhers also lay eggs, which is normal in a way, seeing as they are basically snake-people. Dragons did lay eggs, as least legends say so, but none hatched, as previously mentioned.
Deemi have their own unique way of reproducing. They may look like voluptuous women, but in truth they are hermaphrodites. To make another life, they need the souls/life energy of living beings. They gather them, feed on them, and this creates a new life within them. Every deemi is born by a mother and raised to become another magical predator, set to continue their race. Wraiths, however, remain a mystery. They can become physical beings and tales are told of how they gather, become solid and mate to make new wraiths, but only they know how they reproduce. Wraiths have human shapes but remain hooded and cloaked figures, even when solid, so to think they have human physical attributes is an assumption.
Apart from these mentioned, the monsters tend to reproduce sexually, with males and females coming together, and then females giving birth to the offspring. They have differing ways of rearing these children, but that is for another time. The only thing left to be said regarding monsters is that magi remain the most elusive and mysterious type. They can take many forms so sexual reproduction could be possible, but no one knows if magi need to create new life, let alone if they have. Magi might be immortal and sterile.
Turning to machines for a moment, they can reproduce too. On the one hand they recycle often. Droids that are damaged or even destroyed can be broken down and used to make new ones. On the other hand, more can be manufactured with gathered resources and simple programming. Robotic armies will always swell over time and are much harder to wear down than living beings. Anything highly complex is unlikely to reproduce, however. Creations like that tend to see themselves as the ultimate goal, so making another would either be pointless or perhaps a threat.
All types of life seeks to survive and that means reproducing and doing so in greater numbers than any rivals. Typically, the more ferocious the lifestyle, the more in number they need to be. Gleaners, for instance, aim to produce generation after generation, filling each nest until a new one needs to be created. At the same time, aquatics live with more security in the sea, and with this and much more space, they have grown to considerable number as well.
This is all true of mutants on land as well. Super-soldiers were originally designed and born in labs to fight and prevail. Some still are, but most are born from their parents in more natural ways. Natural procreation has helped to overcome many of the original constraints and flaws placed in their genetic make-up. Not always, but for the most part. It can be that a super-soldier is born from parents who have normal life spans to only live 20 or 30 years. By and large super-soldiers remain instinctive fighters, yet some can be different. Once formed by careful planning, mutants are now subject to the more chaotic laws of nature.
An ugly side of reproduction needs to be brought up, which especially applies when it comes to lesser mutants. It has been known for mutants to have taken humans to forcibly breed with in order to try and remove the deformities and difficulties their kind struggle with. They sought to ease the burden on their descendants, and mostly felt fully justified, seeing as the humans made them this way. At least, this was their view. Mutants made to be superior are clearly less likely to want to breed with anyone or anything lesser than them, yet it does happen. In these instances, it can be attributed to simple lust or rare love. Those born from a super-soldier and human coupling could end up much like one parent or a mix of both. The same is obviously true of breeding with other types. Those who choose this path of reproduction are taking a risk with their future, so it does not happen too often. But it does, even now.
An aspect of all of this is control. In more open, free domains, individuals follow their passions and needs to make more of their own. As simple and true as ever. But when a group is in an enclosed space or living on few resources, or perhaps they have more to fear, then reproduction is under the direction of the collective. In underground bases, people will need to ask permission to have a child and prove themselves capable. In the stricter cyborg sects, reproduction is more like a production line of future members to improve their strength. Among some, people have a duty to make more of their kind, possibly even under duress. Arrangements can be made, compatible partners can be placed together, all to better the community. A good example is the aegis. This race of monsters has fought long and hard to prevent humanity and themselves from being destroyed by enemies. By now, they are not many. To some, this means they must find each other and have children, and then raise those children correctly. Their line cannot end. The world needs them.
In a harsh world, reproduction is just as vital a part of life as ever, if not more so. Life exists in far more varying forms, with different cultures and methods. In many places, you keep to your own. In a few, variety is sought out. Experiments go on, just as the Brainers once created the ultras. Uniqueness exists. As always, there are laws to be obeyed and guidelines to be followed, to give us all an understanding of how life endures. But there are exceptions to the rules and, now and again, those rules get broken.