These aren't aliens. They are the descendants of passengers who woke up early.
Bower and Nadia escape in an ejection pod just before the ship floods. Their pod surfaces on the beautiful, lush coastline of . The ship's computer automatically ejects the remaining 1,211 "untainted" pods to the surface, marking Year One for the new human civilization on a new world. How can I help you further with this movie? If you're interested, I can: Provide a character breakdown of Gallo vs. Payton.
To help humans adapt to Tanis, the crew was injected with an evolutionary enzyme. In the ship’s dark, violent environment, this enzyme caused them to evolve into apex predators over several generations. ⚠️ The Major Twist (Spoilers)