Presence (+) or absence (-) of three derived characters Plant Species Derived Characters Vascular Tissue Seeds Flowers P + + + Q - - - R + + - S + + + T - - - U + - - W + - - The table above shows the presence (+) or absence (-) of three different derived characters (vascular tissue, seeds, and flowers) for several selected plant species. The cladogram below was created based on the information in the table to represent groups of related species. The presence of the derived characters is indicated with arrows. The figure presents a cladogram with the root of the main line at the bottom left and three equally spaced branches coming off the main line. From left to right, the branches are labeled as follows: “Species Group 1,” “Species Group 2,” and “Species Group 3.” Past the third branch, the upper right end of the main line is labeled “Species Group 4.” Three arrows are drawn pointing to the main line of the cladogram. The first arrow points to the main line midway between branch 1 and branch 2. The second arrow points to the main line midway between branch 2 and branch 3. The third arrow points to the main line midway between branch 3 and the end of the main line that is labeled 4. Toxic substances often have a bitter taste that causes animals who try to eat such substances to spit them out rather than swallow them. Additional data suggest that gorilla populations have a very low frequency of nontasters. Which of the following scientific questions will best help researchers determine when the nontaster allele arose in the evolutionary history of the selected primates? Group IV of the cladogram most likely includes which of the following species?单项选择题