Backstory.
Genetic Engineering became common place in the Unified Terran Nations (Old Federation), by the year 2300 A.D; various forms of genetic 'editing' were available to essentially all citizens, with the intention to reduce or even eliminate disease. While the pinnacle of genetic engineering would culminate around the dawn of the 4th millennium with the Terran Genetic and Racial Unity Project, technological advancements leading up to it where nonetheless what one might consider the dawn of the 'post-human' age.
The concepts of Sexuality and Gender had become a subject of contention among human societies on Earth in the 21st century; as progressive elements began to probe the boundaries of what was considered 'acceptable' and more conservative elements pushed back. Ultimately these subjects had become something of a stigma, evolved into human society and social interactions for hundreds of years. For example, the concept of 'gender' and 'sex' were once thought to be innately linked; and it was bred into society to judge individuals' outwardly appearance and demeanour based on the configuration of their bodies' physical reproductive organs.
By the time the Colony Ship Eridonia left Earth in 2090 A.D, her inhabitants of the Western Alliance had already forged for themselves a more progressive society with a future-looking perspective on what it meant to be human. Going forward into the stars, the people of Eridonia would usher in the first of the post-human ages. The seed that grew into the UTN was planted on 2238 A.D and rapid technological, medical and scientific advancement came from the inability to rely on carbon fuels, the lack of established, monopolistic corporation and the overwhelming public drive for progression.
Nanotechnology-based Macro Engineering.
By 2260 A.D, the newly established colony on Eridonia; the world taking the Colony Ship's namesake, had already invested heavily in infrastructure such as medical facilities, hospitals and the newly formed Federal Government had a direct focus on improving the daily lives of the colonists. Extensive research into genetic engineering was made possible by breakthroughs in nanotechnology; allowed by the declassification of corporate and government project files hidden back on Earth - such powers had no interest in the progress of humanity, but were concerned more about preserving their own power.
Nanotechnology ushered in a new age of 'Genetic Macro Engineering'; for example, new cancer treatments and therapies were developed to destroy cancerous cells before they could take hold as tumours; and Nano-tech Serum Vaccines were already in wide circulation by 2267 A.D. Despite some moments of public concern about the proliferation of nanotechnology in a medicinal application, the technology matured and eventually became the backbone of surgical treatments for various physical conditions. Highly programmable nano-scale machines were able to exist within the human circulatory system, regulating cellular activity based on reactions to the body's own enzyme responses; essentially acting as a third, artificial component of the human immune system. Diseases carried in the population from the Earth were all but eradicated, including the common cold; as virions were neutralised by Artificial T-cells within the general population.
Nanotechnology wasn't the end of medical development, however. As the years passed, by the year 2280 new diseases had began to appear; including new pathogens that could exist without activating the Artificial Immune system. The deployment of Nanotech Macro Engineering would be severely curtailed by 2293 A.D after a series of malfunctions in enzyme response of a new series of medicines caused widespread illness and death. Public support for NME declined and it was made clear that medical science would need to push to address issues of human fragility more directly. While NME remained as a treatment option for hundreds of years, scientists and biologists of the young Federation devoted more resources towards active genetic re-coding of human DNA and cells in order to fix innate defects.
Acute Genetic Engineering and victory over Cancer.
The 24th century saw a huge boom in new medical technologies based on Acute Genetic Engineering; the ability to actively re-code human DNA within cells, rather than simply supplementing them with artificial components. Initial trials of new preventative treatments for Cancer; which by the year 2301 A.D was the deadliest natural disease, inherited from the flaws of our own biology, would allow scientists to 're-write' portions of the human DNA code within specialised cells (based on stem cells) that could actively seek and repair damaged DNA and defects to cellular mitosis functionality that would cause a cancer to develop. Public support for the new medicine soared as the first news of a 'Cure for Cancer' became known, and government funding from increased investment in medicine to support the rapidly growing colonial population of Eridonia, allowed vastly increased resources for scientific development. Previously, there was a slowing down of advancement due to funding being diverted to practical applications such as space-flight and long-distance travel between planets and solar systems - all essential for humanity's new colony among the stars.
AGE was finally realised when the New Eridonia Institute for Medical Research announced that internal trials for 'cancer-correcting' cellular gene-therapy had been a huge success. Public support was high enough that more widespread trials began, and despite some initial setbacks to do with immune response (which themselves could be corrected with AGE technology), and huge leaps in Artificial Intelligence Technology with the introduction of the Biomatrix-Processor in 2315 A.D; unlocking orders of magnitudes more intelligent processing capability than before. By 2330 A.D, wide-spread deployment of AGE-technology using reprogrammed DNA had almost completely removed cancer from the population.
The removal of cancer as a cause of death had a direct effect on the population of the new Colony; which almost doubled over the next decade. It became clear that humanity could harness the power of its own biology to forge a better future for everyone. With one of the greatest hurdles of medical science finally overcome, after years of innovation, the first human extra-solar colony was free to focus efforts on perfecting the human gene code and removing essentially all disease caused by defective DNA.
The Post-Human Age.
By the end of the 24th century many new technological advancements in computation, medicine and science were achieved, ushering in the first years of what many Terran scholars refer to as the 'Post Human Age'. Continued advances in AI had allowed entire projects to be overseen by synthetic intelligence, wielding computational power orders of magnitude greater than the entire Earth in the late 21st century; within a single research block. These computers continually scanned and scrutinised human genetic data while scientists oversaw the implementation of 'genetic fixes' for various hereditary conditions and natural DNA decay. The scope of what could be achieved with Biological Engineering was almost limitless.
At the dawn of the 25th century, human fertility issues were all but eradicated as the general population of the new colonies had access to advanced exogenesis-based synthetic reproductive systems - allowing couples to combine their DNA and create a perfectly healthy baby with no genetic defects. Even same-sex couples could combine male-male or female-female DNA to create a healthy baby; marking the dawn of true progression in human society were gender and sexuality soon became concepts of the past, and people no longer looked upon each other with a judgement based on an arbitrary physical biological criteria.
Ethics and Playing God
The 25th century saw extensive unrest among general populations as ethics groups became concerned about the impact of 'designer babies' and racial discrimination at the genetic level when producing an exogenesis child. As such, a series of new laws were put in place starting with the 'Human Naturality Act of 2413 A.D". The new act imposed significant regulation on the extent of Exogenesis deployment, including restrictions on what could and could not be, altered in a human baby. The laws eventually encompassed a huge swathe of genetic changes that were deemed 'unnecessary' by the regulating medical authority and were the first steps in addressing genetic discrimination that had become an apparent issue in the relatively unregulated early days of the Post Human Age.
The Human Naturality Act eventually became the cornerstone for ethical regulation, including imposing significant restrictions on age-prevention treatments that had become available at the dawn of the 25th century: public representatives of the new colonies were concerned that only the 'elite' of society would have access to the best technologies, and would outlast the less advantaged based on socio-economic status rather than merit.
Despite setbacks, the new laws were widely accepted and society began to progress around the issue of 'designer babies', at the turn of the mid-way point of the 25th century, there had only been a handful of high-profile scandals involving elite members of government and corporations, but the Federal government made a point of charging those involved due to the belief that the new Federation's will was only as strong as that of its people. Public support for the 'Government of the people' grew as the UTN started establishing the bastions it was known for, for millennia to come; Equality, Liberty and Prosperity for all.
Gender and Sexuality.
The outdated concepts of what was considered by society to be 'acceptable' for members of certain categories formed based on physical biological criteria such as genetic 'sex' (and reproductive organ configuration' were essentially eradicated from society by the 27th century; many scholars note that it was in fact the social aspect of human society that took the longest to develop and progress; only once barriers to a truly gender-category free society were removed. By the year 2700 A.D; individuals could alter their physical sex based on genetic adaption tools available to the average person; able to allow for various sexual organ development in expediated time frames and couples found themselves able to physically adapt their own biology to suit their relationships. The ancient and archaic ways of thinking that induced gender-based discrimination were eradicated and concepts such as homosexuality were removed as differential criteria due to the fact that every human had the ability to identify as who they wanted.
The slow progression of human societal judgement followed, eventually removing stigmas that would be considered normal to pre-post human societies; such as an outwardly male individual wearing garments considered only 'acceptable' to females, and vice versa. In fact, garment design and fashion followed the trend of gender-neutrality and became subjective based entirely on the tailored needs of the individual client; floral patterns and lighter colours no longer held female-focused connotations for example. Society enjoyed a freedom from the primitive societal definitions of 'gender and sexuality'.
Many couples preferred to remain as 'same sex' couples even after the widespread introduction of low-cost genetic adaption, and society would change too, removing any stigma of outwardly same-sex couples. Actual reproduction was performed using exogenesis on a standardised basis, with any combination of sexuality, or biological, outwardly 'gender adaptions' being able to create perfectly healthy human babies just like any other couple could.
The act of physical sex was regarded as something to enjoy between couples; even though the human reproductive system was still perfectly functional (and in fact, improved - for example the 'female' birth canal defects were corrected), most people preferred to engage in physical intercourse for pleasure in their relationship rather than reproduction - contraception technology allowed for participants to selectively choose the fertility of their reproductive cells at home. Organic reproduction was still 'permitted' by society, as genetic adaption of the foetus could happen naturally within the womb of the female, but exogenesis allowed the development of a healthy child without the need for the physical burdens of pregnancy.
The Peak-Human Age and Human Upgrades.
During the end of the 25th century, such advances in genetic manipulation had allowed almost all genetic-defect based disease to be eradicated, and new, ambitious initiatives were proposed by Medical Institutions; upgrading human biology, in a sense of 'enhanced evolution' to allow Post Humans to thrive among the stars, far from the cradle of safety given to us by Mother Earth for so long. One such advancement was the precursor to the Terran Genetic and Racial Unity project of the 4th millennium; extensive upgrades to the largest and most outwardly human organ, the epidermis; as almost all reproduction by human beings by the year 2600 AD was Exogenesis-based; yearly 'upgrades' to the human genetic information released by the Medical Institutions were considered mandatory for new babies born. Such 'upgrades' included enhancements to the epidermis that allowed for more resilience to ionising radiation, stronger cell formation and vastly quicker healing of wounds.
'Human Upgrades' as they were known, didn't stop there. Each year a new series of upgrades were trailed and deployed that would enhance almost every aspect of the human body, from increased digestive efficiency, increased bone strength, enhanced immune systems and self-healing brain-tissue were introduced. Eventually, upgrades reached the cranial and neurological development aspect and the problem-solving and intelligence of the newer generations began to rapidly increase, as Medical Institutions backed by their Biological Computational laboratories found new ways to enhance the cognition of the human brain. There was, of course, ethical issues and protest from older generations but overall society had guided itself into something more focused on the future of human beings, rather than clinging to the past.
Older generations were not subject to discrimination, as it was deemed that any progress of human intelligence would come naturally with the cognitive upgrades, so major restrictions on generation-based discrimination were set forward. Though, with the new generations came new ethical and moral capabilities and many newer, 'Peak-human' generations became more compassionate for those that came before them, not seeing the need to 'remove the past' but ensure their ancestors lived as best they could be.
Eventually, human civilisation reached a plateau by the middle of the 28th century, intelligence and development peaking at a stage known to Terran scholars as the 'Peak Human age'; every aspect of progression and advancement, both ethical and technological had advanced at enormous rates and human society within the newly formed, star-system-spanning UTN enjoyed some of the most prosperous years of the Old Federal Era.
Genetic Engineering had created what was essentially a new species of humans, smarter, stronger and more resilient in every capacity. By the year 3000 A.D, loosening of the restrictions of the Human Naturality Act of 2413 A.D allowed for the final hurdle of human progress to be addressed: discrimination. It was deemed necessary that, going forward, all terrans became members of a single, unified race; neither black nor white. The groundwork for skin-colour differences being removed was already laid down with epidermal enhancements against radiation in the centuries before; most babies born during this time had a darker, grey-tint to their skin caused by differences in the cellular composition. The Human Naturality Act continued to prevent 'customising' babies based on factors deemed unnecessary so the transition to the new Terran Race was largely natural and a result of human genetic engineering, allowing human beings to live among the stars with resilience and adaption for the millennia to come.
Of course, vices that gripped human societies such as hatred and discrimination still existed, but their focus had simply changed from arbitrary concepts such as race, gender and sexuality, to more political and geopolitical topics spreading around the dozens of Star Systems now under the flag of the Unified Terran Nations. Humanity would remain conflicted and divided, as is our nature.