The lecture challenges the theories presented in the reading about why giant squids have such large eyes. Each explanation given in the reading is addressed and refuted by the professor with compelling arguments. Firstly, the reading suggests that giant squids have large eyes to aid in hunting small prey in the dark ocean depths. However, the professor argues that despite their enormous eyes, squids cannot rely on sight due to the minimal light at such depths. The prey remains practically invisible regardless of eye size, prompting squids to depend more on touch rather than sight for hunting. The professor points out that giant squids often hang motionless with tentacles extended, waiting for prey to brush against them, indicating that keen eyesight is unnecessary for their hunting approach. Secondly, the reading posits that large eyes might help squids find mates in the vast, deep ocean. Yet, the professor highlights that giant squids are capable of mating at a young age when their bodies and eyes are still small. This suggests that enormous eyes are not essential for reproductive success, as the smaller-eyed young squids manage to reproduce effectively. The professor asserts that if eye size were critical for mating, even youthful squids would possess larger eyes, which they do not. Finally, the reading argues that giant squids' large eyes could help them detect sperm whale predators by observing disruptions in bioluminescent organisms. The professor counters this by explaining that sperm whales locate squids using echolocation, detecting sounds from up to 300 meters away, a distance far beyond what squids' eyesight can achieve. This renders the large eyes ineffective in avoiding these predators, as the whales find and approach them well before the squids can visually detect their presence.