Imagine that certain laws of physics could be ignored and you were able to travel vast distances in moments. Now imagine that you traveled to an Earth-like planet located light-years away that is known to support life. Think about what you've learned in this unit and make an argument for what you think would be the dominant type of life form on this planet. Consider whether a notochord is required for an organism to manipulate its environment and become a dominant creature.

Depends whether mainly oxygen and water were present on this planet, as well as sunlight. For any earth-like life forms to exist, physiological processes cannot be envisaged to occur outside of aqueous solution, and oxygen (in our limited vista on earth) is the only gas/"chemical" capable of supporting a process (respiration on earth) that can generate energy in the form of ATP. For a photosynthetic process to occur (assuming plant-like life) some kind of phtoopic energy would be necessary, ideally from a nearby star (similar to the sun). There are many invertebrates on earth (no spinal column - notochord) that live a successful existence - not least insecta (a group of arthropods [arthro = joint pod = legs: therefore jointed legs, others being arachnida [spiders], crustacea eg crabs] that are extremely successful and well-adapted to the earthly environment, so such life forms could exist.