Galactic Ancestries
Source Galactic Ancestries pg. 5
The ancestries presented in this book represent civilizations found all across the Starfinder setting. They might exist on countless worlds or be relegated to a single planet, such as one of the Pact World, and some of them might even have origins that trace back to other planes of existence.
One thing to keep in mind when using the ancestries presented in this book (or in other Starfinder products) is that the rules for a given ancestry can easily be used to represent a previously unencountered species. As a player, if you find an ancestry with mechanics that appeal to you but you want to approach its culture or mannerisms in a different way, then you should confer with your GM about introducing those changes into your game. Some ancestries, such as kasathas, possess mechanics highly tied to their cultural background, but these can easily be adjusted to represent different aspects of a species that uses the kasatha ancestry as a template.
Another consideration when retooling an existing ancestry in this manner is the presence of languages. If an ancestry has an existing language, such as a bantrid's Bantridi, then you should consider adjusting that language. For example, if you create a new ancestry of rolling organic balls called zamurzans that uses the bantrid ancestry in this book as a base, you should consider swapping out their language for something bespoke, like Zamurzan. Of course, it's important to review this with your GM before beginning a campaign, as a prewritten adventure won't include Zamurzan unless your GM makes appropriate alterations!
One thing to keep in mind when using the ancestries presented in this book (or in other Starfinder products) is that the rules for a given ancestry can easily be used to represent a previously unencountered species. As a player, if you find an ancestry with mechanics that appeal to you but you want to approach its culture or mannerisms in a different way, then you should confer with your GM about introducing those changes into your game. Some ancestries, such as kasathas, possess mechanics highly tied to their cultural background, but these can easily be adjusted to represent different aspects of a species that uses the kasatha ancestry as a template.
Another consideration when retooling an existing ancestry in this manner is the presence of languages. If an ancestry has an existing language, such as a bantrid's Bantridi, then you should consider adjusting that language. For example, if you create a new ancestry of rolling organic balls called zamurzans that uses the bantrid ancestry in this book as a base, you should consider swapping out their language for something bespoke, like Zamurzan. Of course, it's important to review this with your GM before beginning a campaign, as a prewritten adventure won't include Zamurzan unless your GM makes appropriate alterations!