The Worlds of Humanity had long been vastly overpopulated to the extent that across the thirty thousand or so inhabited planets there was no longer room for constructing space ships. Previously builders yards, industrial estates and space ports had taken up billions of square kilometres, but over the centuries and millennia living quarters had encroached. Now each human being inhabited, at best, a one by one point five metre sleeping pod. These were stacked thousands high across the land and sea of all inhabited planets. No room was left for industry, agriculture or commerce.
Attempts were being made to construct massive intergalactic space ships in orbit around planets, using space elevators to carry workers and materials up to the orbital shipyards. Problems were multitudinous. Hastily build space elevators often toppled, crashing to ground and killing millions at a time. As this only reduced the population numbers it was not considered a major problem, and under certain jurisdictions was actually encouraged. Oftentimes towers were built up to space and then pushed over without them ever being intended as space elevators.
Even with the millions being randomly crushed by falling debris, and the constant rebranding of mass forced sterilisation, the numbers continued to rise. People still enjoyed the vigorous putting-together of body parts, and given certain combinations and conditions this could still result in birth. A plus one to the population.
Occasional settlements were made on new lands in new systems, but the exponential growth of humanity far outstripped the tiny expanses of living space. Regular competitions ran, and prizes were granted, bringing in a regular supply of practical and impractical ideas for reducing population size. All news and politics was focused on the unstoppable population growth.
One of the most successful of ideas implemented was instigating the death penalty for all crimes; the definition of 'criminal' expanded to include being related to a criminal, giving birth without a license, giving birth with a license, being a parent, being a baby, having previously been a baby, or ever having seen or heard a baby. As this included everyone it enabled police forces to simply vaporise perpetrators on sight. The only problem with this was that every morning all officers would begin the day by vaporising their colleagues, if they managed to make it out of the sleeping pod without vaporising themselves. Billions were enlisted into the police force, and billions died before they had a chance to set off on their morning beats.
Azygous and Thule were talented scientists, able to manipulate the natural world using the tools of their trade. Electron microscopes, graphene doodahs, and quantum computers. DNA blenders and molecular recalcifiers. They, like many others before them, made many attempts to combat the population problem, for that was the only problem faced by science. The curing of disease and the prevention of ageing no longer concerned science. Once scientists had tackled these problems, which turned out to be a major contributing factor to the staggering number of humans crawling over every available surface, and all the unavailable ones too.
Some scientists were manufacturing diseases, the biggest prizes going to the biggest killers. Others made more efficient and less expensive killing machines which the authorities distributed through junk mail and cereal boxes. Some even created artificial means of starting mass panic, sending people running into the streets to kill their neighbours and themselves. People were dying in piles, bodies rotting in the streets and in their beds. Conservative estimates envisioned anywhere between fifteen and eighty five percent of sleeping pods contained at least one corpse. Nobody had the faintest clue how many humans there were. Who had the time to count when every moment was spent killing, dying or barely surviving?
Azygous and Thule had initially tried this way of killing and that way. Something about buzz saws randomly leaping out of pavements had brought chuckles and popular approval but had proved too costly. Another wheeze whereby people were encouraged to declare war upon themselves was still ongoing, and providing consistent low-level relief.
One morning over a well-scavenged breakfast of shoe leather and the feet they contained Thule had a thought:
“What's the one thing, above all else, that is still contributing to the population growth?” asked Thule.
“Well, aside from the fact that death by old age is not really a thing any more, I would have to say that it is those blasted babies that keep being born,” Azygous correctly surmised.
“Precisely,” said Thule. “My thoughts exactly.”
“Yes, mine too,” reiterated Azygous. “But we know sterilisation and the various infanticidal programs have failed, so I suppose you are suggesting turning the problem on its head.”
“I hate to repeat myself,” said Thule. “But on this occasion I must: Precisely.”
“Birth is caused, we know, by certain couplings in certain combinations and conditions. What these certains and certainties are is of no great concern to naught be the greatest of perverts and proles, and we know that even the threat of death by disease cannot prevent these couplings. Nor should they, for what other pleasures have we left?"
"None of note," pointed out Thule.
"Capital punishment, and terminal disease have not worked; the numbers continue to grow."
"Our next move is clear," agreed Thule.
Together they worked night and day, for forty weeks and forty more, testing, retesting, publishing, peer-reviewing, testing and more testing. They got through enough phials, test tubes and vials of blood, sweat and tears, to arm and attire the entire Perspex Army of Methyl Metha and the Crylates. They experimented with every rung of every DNA strand they could lay their hands on, climbing up and down like master gymnasts. They perfected the medicine and morphology behind their technique before working on delivery methods. A great idea is nothing without the ability to spread it across all the lands and living spaces that humans have crawled into. Finally they were ready to reveal their grand formula to a waiting world.
Azygous and Thule presented their work to the appropriate authorities in the Grand Hall of the Purging of the People. Two test subjects took to the stage and began their coupling. They grew more vigorous and jiggly, jumping about and squeaking. They finished together and fell down together, squishing themselves closely and cosily into one. The beast with two backs became the baby with one back as the sexual partners merged into one leaving behind only a single new-born, to be cared for or disposed of as society saw fit.
Rapturous applause filled the hall as all present understood the powerful implications of the new technique in genetic manipulation. Two literally became one. Every time a baby is born, the population would decrease. Eventually, after a hundred or so generations, when all alive were conceived in this way the population will achieve a state of exponential decrease along the exact same curve it had previously increased. This is what Azygous and Thule's experiments predicted would happen, and this is the outcome the authorities agreed with.
History tells us this is indeed what happened, presenting us with out present problem, whereby humanity exists in small isolated scatterings, strewn across the galaxy and facing immediate extinction due to the problem of high child birth. Long forgotten voices spoke of Azygous and Thule as saviours of humanity, but their salvation was only temporary, for now the solution to a problem of the past is the immediate threat of the present. Our entire and final obliteration is imminent. Not by a sudden Apocalyptic catastrophe, but by the lonely death of the last human.