Need requires context. “if they don’t have it, they don’t need it to survive”. And survival is conditioned upon the environment. If something emerges that exploited the blindspot, then we’d need it to survive.
What was the evolutionary pressure that caused receptor orientation to be different in cephalopods that vertebral animals didn’t encounter? Or did they encounter it and have other adaptations that allowed it to deal with them.
Not really. Needs is a fairly strict word. If it was needed they would not survive without. Useful, i agree with you
Need requires context. “if they don’t have it, they don’t need it to survive”. And survival is conditioned upon the environment. If something emerges that exploited the blindspot, then we’d need it to survive.
What was the evolutionary pressure that caused receptor orientation to be different in cephalopods that vertebral animals didn’t encounter? Or did they encounter it and have other adaptations that allowed it to deal with them.