Many researchers who study the kingdom Protista argue that all of these organisms should not be placed in the same kingdom because these organisms could not have evolved from a common ancestor. In other words, they argue that the kingdom Protista is __________.

• A. paraphyletic
• B. monophyletic
• C. heterophyletic
• D. None of the listed responses is correct.
• E. polyphyletic

Answer: (E)

Verified step by step guidance

1. Understand the definitions of the terms: Monophyletic refers to a group of organisms that includes all the descendants of a common ancestor. Paraphyletic refers to a group that includes some, but not all, descendants of a common ancestor. Polyphyletic refers to a group that does not include the most recent common ancestor of all members of the group.
2. Consider the argument presented: Researchers claim that organisms in the kingdom Protista did not evolve from a common ancestor, suggesting that they do not share a single lineage.
3. Apply the definitions: Since the organisms in Protista do not share a common ancestor, they cannot be monophyletic. If they were paraphyletic, they would share a common ancestor but not include all descendants, which is not the case here.
4. Evaluate the term 'polyphyletic': This term is used when a group of organisms does not include the most recent common ancestor, indicating multiple evolutionary origins.
5. Conclude that the correct term to describe the kingdom Protista, based on the argument that they do not share a common ancestor, is polyphyletic.