Gene Lots

When the Central Authority was directing humanities expansion through the stars, there was a fear of the degradation of the human genome over time as humanity was split up across greater and greater distances.
Given enough time, the population of colonized planets might fall prey to defects present in their original starting population, which would then explode as that population grew.
In hindsight, there likely wasn't that great a threat, but if there ever was, the Authority's answer solved it well enough that it wouldn't be a problem, even to this day.
The Gene-Lots were a set of genetically crafted people, built from genetic material given by willing donors (after a significant and some would say invasive examination for the possibility of congenital defects or other things that would be damaging to the quality of life) and randomized enough that they couldn't be tracked back to any singular pair of donors, and shipped out with colony expeditions. Once the colony was established, the Gene Lot would be opened and the embryos contained within would start growing.
Once old enough, the babies could be removed from their "cribs" and would then be raised as normal children for the rest of their lives. This genetic diversity introduced to a colony, curated as it is, would prevent the diversity of the population from becoming a closed circuit. This was especially important in colonies that did not have a lot of traffic. Ironically, garden worlds often suffered from this as they did not necessarily need to import many people or materials as all were provided for them.
It's unclear if it was intentional or an unforeseen side effect of the Authority's methods, but this process seems to have introduced several gene-expressions into the population that were uncommon or impossible before. New eye colors became common as well as hair color.
One unfortunate aspect of this system is that it disappeared with the Authority returning to Sol and forming the Shield Wall, and as such it can no longer be used to aid colonization efforts. That being said, there have been several instances of Gene Lots being found years or centuries after the Authorie's recall, oftentimes in large vaults that had been hidden away and/or sealed in a way that prevented non-Authority access for the longest time. These Gene Lots can be quite the boon and are often auctioned off by the Colonial powers for high prices.

Utility

While there was usually a Gene Lot sent with the initial colonizing force, there could be delivered and introduced at really any point in a colonies lifespan. There are some pre-Asteriomachi records of pupulations requesting a Gene Lot be sent to them because their population was currently fine but they predicted a donwturn in numbers some-time in the future.

Inventor(s)

Central Authority

At the time and into the modern day, it was a common "theory" that the Gene Lots were made so the Central Authority could introduce a population with some sort of 'sleeper activation' encoded into the DNA, but nothing has ever supported that assertion. Most would point to the Asteriomachi as enough evidence, as there was never any known instnace of such a thing happening.