The grand canyon was carved out by the colorado river. this caused the separation of members of a squirrel species. abert’s squirrel lives on the southern side of the canyon and in other parts of the united states. a subspecies, the kaibab squirrel, is found around the northern rim of the canyon and nowhere else in the country. as shown here, the two squirrels differ in body and tail coloration. their ears are also different. these variations are the result of

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.