Which clue indicates that a speciation has occurred between two populations? a. two different looking individuals are within the same population. b. interbreeding between two populations is impossible. c. a physical barrier such as a mountain range separates a population. d. renaming of a population has been complete by scientists.

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.