Star Trek: 10 Alien Species That Are Actually Related

All life on Earth is related. We are all descended from the first single-celled organisms that formed on the planet eons ago. Over the course of billions of years, evolution split life off into countless different species, but, amazingly, all of the Earth's living things remain part of one huge family.

In Star Trek, every alien planet has a family tree just like ours, and there are actually many sentient alien species that share common ancestors. Some of them split off by moving to another planet long ago in the past, while others simply evolved alongside each other on the same world. Some form powerful alliances, others wage war, while some chose to simply ignore each other.

In this list we're going to discuss ten sentient Star Trek aliens that are related evolutionarily, and explain when and how exactly they became separate species.

The Vulcans and the Romulans are the most well-known species to share a common ancestor. The Romulans were Vulcans who left the homeworld during the 'Time Of Awakening', when Surak began reforming their society and teaching Vulcans to purge their emotions.

Eventually, these rogue Vulcans made a new homeworld in the Romulus system. Many Romulans kept the appearance of Vulcans, but those who lived in the North of the planet adapted to have stronger, V-shaped head ridges. The Romulans show us what Vulcan society may have been like if they never embraced Surak's teachings. They were just as intelligent, but more power-hungry and isolationist.

The Romulans fought a war against Earth in the mid-22nd century, but, since the two sides never directly saw one another, humanity didn't learn that they were related to their Vulcan allies until about a century later.

It was a long and difficult process, but the Romulans were finally reunited with their Vulcan siblings in the 32nd century. The planet Vulcan was renamed Ni'Var in the name of unity, and the two species were finally able to coexist peacefully.