Humanoid

"All humanoid life has a similar genetic pattern." - Data (TNG|Genesis)

A humanoid is an intelligent bilaterally symmetrical, bipedal lifeform in possession of an upright posture, two arms, two legs, hands, feet, one thorax, a neck, and a head with a brain located in it. They are generally mammalian and originate on Class M planets. It is common for them to have two sexes. Among the many humanoid species known throughout the Milky Way Galaxy are Andorians, Betazoids, Bolians, Bajorans, Cardassians, Hirogen, Klingons, Humans, Romulans, and Vulcans.

Despite the vast distances separating their homeworlds, many humanoid species have been found to share a remarkable commonality in form and gene|genetic coding. These similarities were believed to be evidence of a common ancestry, an ancient humanoid species, who lived in our galaxy's Distant past#4.5 billion years ago|distant past some four billion years ago.

To preserve their heritage, this species apparently seeded the primordial water|oceans of many potentially hospitable planets with encoded DNA fragments. The genetic information incorporated into the earliest lifeforms on those planets and through preprogrammed mutations caused by a genetic template, directed evolution toward a physical development similar to their own. Because of this controlled mutation mechanism, most habitable planets in the galaxy evolved with many physically similar species (e.g. fish, trees, dogs, insects), and on many of those worlds with at least one sentient species with a humanoid configuration. Most of these humanoids are even Interspecific interfertile with each other.

Anatomically, a significant percentage of those lifeforms are outwardly indistinguishable from Humans, right down to such morphological minutiae as the same racial phenotypes, hair distribution patterns, fingernails and cartilaginous foldings of the nose and ears. The reason they are so astonishingly similar to the Human race is because the "Human form" represents the basic way that evolution most likely takes for the dominant mammalian race on an average Class M planet under the influence of the genetic codes and the other humanoid races (e.g. Klingons, Cardassians, Vulcans) developed under very specific and usually unique environmental conditions.

In one of the most remarkable scientific detective stories in history, archaeologist Richard Galen of Earth uncovered the similarities between certain DNA sequences in life-forms from widely separated planets. He discovered that these DNA sequences were a puzzle deliberately left behind by these ancient progenitors. The DNA sequences, when assembled by protein-link compatibilities, formed an ingenious computer program, a message of peace and goodwill to their progeny. This message, assembled in 2369 in an unprecedented example of interstellar cooperation, was a confirmation that many humanoid species in this galaxy are indeed members of the same family, despite their significant differences. (TNG|The Chase)

Taxonomy of humanoids

• Avian (Humanoid)|Avian
• Mammalian (Humanoid)|Mammalian
• Proto-humanoid
  • Proto-Vulcan humanoid
• Saurian

It seems that Kobheerians, Dopterians and Ferengi may be of the same group (currently unspecified). It should be noted that the brain of the 'as of yet unseen' Breen shares their four lobed structure which may indicate similarities.

Another possible group are the Algolians, Promellians and Pardshay's species.