What is the geographic extent of the prairie/forest-prairie transition in North America?

Which of the following statements is true? a. the main cause for speciation is an increase in gene flow. b. organisms that reproduce asexually are not considered part of a species. c. on a tree of life diagram, speciation is shown by the merging of two different lineages. d. the size of the geographic area inhabited by a population can cause speciation.

Regarding most of the narrator’s story, which word best describes the tone?

What noticeable trend from this graph might be used to make a conclusion?