Biologic advantage of magnetoception

Question

Humanity is often said to have 5 senses, but this isn't entirely accurate. This is one question of several in a series I am asking regarding going beyond the 5 senses.

Magetoception is one of the others. It's strongest in birds (although there's some debate about that--there's evidence that they use a kind of sound sonar to actually navigate).

The mechanism for this is not completely understood; it is theorized that this has something to do with deposits of ferric iron in our noses. This would make sense if that is correct as humans who are given magnetic implants have been shown to have a much stronger magnetoception than humans without.

If I were building a race with an expanded version of this sense, what would the advantages be evolutionarily? From what I have looked at, navigation is the big one, but I don't know how else it would help and what the advantages might be.

Answer 1

Depends partially on the planet. The stronger the magnetic field the more precise the sense is. Now if certain animals would have a large enough magnetic field this would be a clear advantage for a hunter.

Any other advantages really are just linked to navigation. Either migration or sensing very specific routes around hazards. Perhaps gathered by trail and error, much like ants.

Another good point might be poor visibility. Either weather or underwater etc. This limited visibility would give a superior sense of navigation a clear advantage. Same in a dark cave system. Perhaps local ore deposits would be landmarks.

After most evolution would've stopped we get obvious advantages with technology.

Answer 2

I don't know about evolutionary advantages, but I do know of an interesting example of magentetoception. A powerline worker underwent an experimental surgery, embedding a bunch of very tiny magnets in his fingers. When his hands got near a high voltage AC power line, the magnets interacted with the magnetic field around the wires generating a small current to be detected by his neurons. The result was impressive: he could tell if a line was hot or not simply by bringing his hands near the line.

Answer 3

It does not look to me that magetoception would have any evolutionary application apart from navigation. In nature, magnetic fields can be associated with large deposits of (typically iron) ore - but for species that we have here on Earth, these ore deposits do not make any difference - ore does not provide food, shelter or pose any danger.

However, we can imagine an iron-poor world where available iron gets accumulated by the living organisms and deposited after they die. So, these iron deposits become an oases in otherwise barren landscape. Species of this world might develop a sense for finding such oases and navigate between them.

Answer 4

One advantage is that it makes you somewhat sensitive to radio waves. A more advanced magnetoreception sense could give you reasonably fine radio sensitivity. This could further help with navigation, allowing you to sense deep-space radio signatures during the day. It could also be used to sense lightning that is invisible to the naked eye. That could be useful in an area with heavy storms. And of course in the modern world it would be both very useful and very irritating.

Answer 5

Creatures which can perceive magnetic fields might be able to detect storms. In a circumstance where powerful storms (of different types) are a threat, the ability to detect them coming and seek shelter would confer a survival advantage and so evolutionary benefit.

Thunderstorms. Everyone knows thunderstorms have lightning and where there are powerful electric phenomena there are induced magnetic phenomena. Thunderstorms can kill via lightning, flooding, tornadoes or high winds. Linked is an article describing far-ranging magnetic fields which might alert sensitive creatures to an incoming storm.

Dust storms It has always seemed to me that dust storms should have more associated electrical phenomena that thunderstorms, by virtue of the nonconductive particles of sand / dust rubbing against each other. I know that dust storms can have thunder and lightning too. Here is an article describing how the static electricity within a dust storm serves as a sort of feed-forward loop, augmenting the storm. As with thunderstorms, electrical phenomena mean magnetic phenomena.

Earth storms aka earthquakes. It would make sense that the movement of large magnetized pieces of the earth's crust would generate magnetic fields. It is theorized (but I think unproven) that magnetic waves due to these changes can precede and possibly predict earthquakes. How does that confer evolutionary benefit? I am reminded of the story of elephants which sought high ground in advance of the Indonesian tsunami and so were not washed out to sea or drowned. In an environment where earthquakes lead to tsunamis, landslides or other threats to life, the ability to detect them and seek high, flat ground would lead to increased fitness.

Solar storms We are protected to a large degree from these by our magnetosphere. But should that change, or on a planet where that was not the case, or on a planet where solar storms were more severe, the ability to detect one coming (and hide deep underground!) could definitely confer a survival advantage. Solar storms induce big changes in the earths magnetosphere, which would be detectable. I can imagine a magnetically tuned ancestor whimpering deep in a cave during the solar storm while its untuned conspecifics strolled merrily about in the sun, the incoming radiation mutating their gametes.

Answer 6

It's all about plumage. If acquiring iron, or avoiding the Zapper beasts, is a survival benefit, then mates will be drawn to those demonstrating the survival benefit.

Literally. Those that can draw the mates with magnetic powers will draw the mates.