With the Epigenetic Triggers and Gene Tailoring technologies, it is possible to spend Gene Points on different Species found in the Species View to alter their Traits and Climate Preference. The amount of Gene Points you have depends on the species you are attempting to genetically modify. The goal is to either alter an existing species or uplift a pre-sentient one. The primary currency for genetic modification (during uplifting or otherwise) are Gene Points which are hard to come by:
- when you first research genetic modification all species will gain 1 gene point. Later Genetic Modification techs will increase the gene points you have available for all species.
- you get only up to 2 additional gene points from techs. So choose wisely how to spend them.
- leftover trait points from empire creation are translated 1:1 to gene points. That means a species with 5 negative traits could have up to 10 gene points to spend (1 base + 2 Trait Points + 7 extra Trait points). And adding an additional negative trait might give you a extra gene point later on. However, removing negative traits costs gene points too.
Unless you are extremely lucky this technology will come in the mid/late game (depending on the size of the galaxy).
This is done on already existing sentient species in your empire and allows you to adapt them better to different climates or challenges of the later empire. Genetic Modification allows you to add and remove traits much like through empire creation except you cannot remove positive traits even if they're from a previous genetic modification, and you cannot give negative traits. Climate preference can be changed without spending Gene Points or adding traits, however you still need at least 1 gene point to start the Genetic Modification process. When you genetically modify a species you can choose which planet(s) where the species resides that you want to apply the changes to. When you genetically modify any species that new fork will be considered a subspecies. It suffers a lesser version of Xenophobia regarding to the original species and vice versa.
After you commit to changes a Special Project is added to the Situation Log. It will vanish after 60 days if not started, or if it is interrupted. The cost in Social Research scales linearly with the number of affected people and number of spent Gene Points.
Just ordering the Genetic Alteration process without actually spending traits points (like changing habitability) costs 400 Social Research per effect Pop. Every Traitpoint spend will increase to cost by 100 Social Reserach per Pop.
Uplifting only applies to certain "pre-sentient" species that are co-existing on one of your colonies. Generally those species would become sentient on their own, if just given a few million years. The player simply sidesteps that process. All rules for Genetic modification apply, except the following:
- it requires Epigenetic Triggers, which is outside of the normal Genetic Engineering tech chain.
- the uplifted species is immediately integrated into the empire that uplifted it.
- all upliftable species have a special trait that can not be acquired during Empire creation or genetic modification. This trait will make them excel at some jobs far beyond what normal species can do, but often at the downside of making it unsuitable for other purposes.
- the species will be naturally thankful to the species that raised them and get +20% happiness if in the same empire as their benefactors. The exact conditions for this are not clear.
- the species will appear with Neutral Ethos. Quest chains give the uplifting Empire an opportunity to help decide the species' core ethos, or allow them to stand back and let the uplifted species decide for themselves. The species is fully subject to Ethics divergence, with the Happiness bonus often resulting in an indirect boost to divergence.
This section may contain outdated information that is inaccurate for the current version of the game. The last version it was verified as up to date for was 1.3.
The exact mechanics of what makes two pops belong to the same species are not fully known as of 1.1.0. However, some data has been gathered from testing and analyzing savefiles:
It appears the game stores all distinct species in the savegame in form of a simple list. When any pop is modified, it is first looked if a species with exactly matching properties is already in the list. If the exact match is found, no new entry is added and the species index is re-used.  It also appears that the order of traits matters for two pops to belong to the same species. Thus, if the same genetic engineering is applied in the exact same order, planet by planet, it should result in a single final species.
The game recognises the preset human empires United Nations of Earth and Commonwealth of Man as sharing a common race, even if the player edits their racial traits during game set up. For example, if a player using Commonwealth of Man without the Nomadic trait encountered the United Nations in-game, the population of the latter empire would also lack the Nomadic trait, and would appear under a single entry in the Contact View.
As of 1.2 intentional Genetic Engineering will track modified species as "subspecies" of the original wich have a lessened Xenophobia effect compared to a completely alien species. (-2%/-7% Alien overlord penalty instead of -10%/-30%). Subspecies may still be subject to certain Xeno-only policies, like slavery and purge. But they do not suffer Leadership and voting related Ethos penalties.