The Vulcans or Vulcanians (Second Human Empire: ?) were a warp capable humanoid species from the planet Vulcan. They are widely known for their logical minds and stoic culture. Their homeworld became a founding member of the United Federation of Planets and a member of the Alliance of Nations. Genetically, Vulcans and Humans were similar enough that they could produce offspring without any problems. Externally, Vulcans were generally similar to Humans, the chief exceptions being the Vulcans' notably arched and up-swept eyebrows and distinguished external ear structure, the top of which tapered into a clearly defined point. Most Vulcans had straight, glossy dark brown or, more commonly, black hair and pale skin with a very subtle greenish tinge, much as the skin of Humans of European descent had a very subtle reddish or pinkish tinge. However, some Vulcans, including Tuvok, had brown skin, tightly coiled black hair, and physiognomic features similar to those found in Humans of African descent. Others shared physiognomic features similar to those found in Humans of East Asian descent. However, most Vulcans had a vaguely Eurasian appearance.