Near-Human
From TARDIS Index File, the free Doctor Who reference.
A near-Human is a type of humanoid whose external features closely resemble that of a Human's, either due to ancestry or coincidence. Some species of near-Humans seem to be biologically identical to Humans, including Trakenites and Trions, while others have various internal and external differences, such as Logopolitans (who have enlarged craniums), Futurekind, who have sharper teeth than humans, and Time Lords (who have several differences, including the ability to regenerate, a binary vascular system and a respiratory bypass system).
[edit] Theories
One of the more popular theories as to the many near-Human and humanoid species is that the evolution of Gallifreyans relatively early in the history of the universe affected the morphic fields of other life forms, which influenced the development of later species in a similar direction. (NA: Lucifer Rising)
Another implies that the founding Time Lord, Rassilon seeded the early planets with biogenic molecules that would develop into humanoids, specifically ones which resembled Gallifreyans. (BFA: Zagreus)
In the 1966 Peter Cushing movie, a Thal suggested to the human Susan that the resemblence between the two species was due to humanoid form being ideal for survival.
