By “regress”, I mean essentially to de-evolve. The opposite of progress. Nature does not allow for backwards evolution. Everything moves towards natural adaptation. Never away from it.
A purely cave dwelling fish doesn’t need sight. So, over time- it will lose its sight in favor or other senses, such as smell or the ability to sense sound waves and motion. Also, eyes can be a disadvantage to them as they no longer need to devote energy to a useless sense.
What do you mean by “regress”? Is the Mexican tetra un-evolving its eyes not a regression?
That’s considered an adaptation. So, no. It didn’t de-evolve. It adapted to its environment and over time, shed a useless function.
What is gained by having no eyes? Can you answer my question about what it means to regress?
By “regress”, I mean essentially to de-evolve. The opposite of progress. Nature does not allow for backwards evolution. Everything moves towards natural adaptation. Never away from it.
A purely cave dwelling fish doesn’t need sight. So, over time- it will lose its sight in favor or other senses, such as smell or the ability to sense sound waves and motion. Also, eyes can be a disadvantage to them as they no longer need to devote energy to a useless sense.