TPO43 Integrated

The passage and the lecturer both talk about the theories that agnostids, a group of marine animals, may have lived. The author presents three different views about how these animals might have survived. On the other hand, the lecturer refutes all the mentioned notions in the text and believes that all of them have serious weaknesses.

In the passage, the writer begins by stating that the agnostids may have been predators who lived in the ancient ocean. The professor, however, asserts that all predators have large and well-developed eyes, and vision is crucial for them. Since the agnostids did not have vital eyesight and were blind, they needed other sensory organs to track the prey. But there is not any evidence of such organs on remained fossils.

The author also claims that they might have dwelled on the seafloor. Conversely, the lecturer argues this viewpoint, mentioning that seafloor dwellers could not move fast and stayed in localized areas. On the other hand, evidence shows the agnostids were able to move fast and far distances. So, they inhabited multiple geographic regions.

Finally, the writer points out that the agnostids might be parasites and survive in this way. In contrast, the lecturer states that the population of parasites should be a specific limit to do not kill the host organism. According to agnostids' fossils that have been found, it is apparent that they had a vast population. Therefore, the great size of agnostids rules the idea they were parasites.