Originally posted by galveston75
Soooooooo exactly how did this just happen for these amazing fish?
I don't know exactly, and apparently nobody else does either.
However, based on our knowledge of other traits of living things, it almost certainly followed this general pathway:
1. In one of their ancestors there existed the necessary components for navigation, (whether they use smell or magnetism or a combination).
2. Those components existed for some other reason, either they were useful for something else or were a side effect of something else useful. Or just occurred by chance in a few individuals.
3. The components proved useful to some individuals, and as a result of natural selection they improved, and spread through out the population.