The human population of Terra (typically called Terrans or more specifically referred to by their ideology) are a people widely speculated as having evolved on the planet Kobol and descended from a community believed lost during the exodus from Kobol to the Colonies. They are a technologically modern race.
A bilaterally symmetrical bipedal primate, Humans are a warm-blooded mammilian species with an average lifespan of around 90 years, although some individuals achieved a much older age. They consider themselves distinct in their ability to introspect, communicate through language, and reason and problem solve abstractly. Their rationality, intelligence and self-awareness is a particular identifier of 'humanity'.
The Terrans number some 5.5 billion all on the world Terra. Their own history and tradition focuses on Terra as their homeworld and from which they originated. Appearance and phenotypic characteristics are superseded as fast identifiers of a Terran by Ideology and position within their ideological community. Genetic engineering is accepted, and utilised to improve natural human ability. Cloning is also conducted extensively by a community of Terrans and they are not treated any differently from citizens within that state. Not officially known of by the Colonials nor encountered; Terrans do not believe that other intelligent species exist beside themselves and they are more insular as a result with competition between ideologies dominating their history and current politics. There are projects underway that seek to settle nearby moons.
Nationalists are a democratic community of peoples who value freewill and self-determination deeply. They are an egalitarian, thoughtful collection of smaller populations who maintain their own cultural identities but have banded together for mutual, shared benefit. Enjoying a good standard of living for the most part, though poverty is an issue actively combatted, they value ethics and the 'noble individual'; who while being self assured and independent actively participates and serves to improve the experience of all around him. Nationalists, as such, believe in and acknowledge a shared desire for peace, and the need for cooperation to preserve their ways of life. Flexible but loosely aligned, wealth is not evenly distributed though opportunity is.
Allies come from a regimented, martial regime that holds the needs of the Alliance over the worth of the individual. Service to the state is expected, as identity is tied to the work a citizen does for the Alliance and the measured meaningfulness of the contribution to the advancement of the country. Indoctrination begins from childhood with membership to a youth organisation. Thereafter special education and training, good position and regard are extended to the most politically reliable individuals. Citizens are not afforded many rights but are extended certain privileges per their standing. The state is geared towards the total domination of Terra and the stars, but recently has been focusing on the stars. It sees what lurks in the vast darkness above as the most dangerous enemy unknown and are particularly secretive and paranoid as a result.
While highly classified and deniable, it is understood that Terran military formations have encountered 'Fringers' from the Colonies. Being beyond the Red Line, the level of contact between Terrans and Fringer extra-terrestrials is unknown and as a rule unacknowledged on the world. Because they lack faster-than-light means of transport Terrans have not ventured beyond their home system beside sporadic exploratory probe launches. They have launched manned missions to moons and worlds in their system that might one day soon host populations. There world lies perilously near a Cylon avenue of space.