Chennai: What gives some animals a ‘sixth sense’ that allows them to detect the Earth’s magnetic field? According to a new study from the University of Central Florida, the answer may be much more simple than what was expected.
A University of Central Florida researcher is co-author of a new paper that may help answer why some animals have a magnetic ‘sixth’ sense, such as sea turtles’ ability to return to the beach where they were born.
“The search for a mechanism has been proposed as one of the last major frontiers in sensory biology and described as if we are ‘searching for a needle in a hay stack,” says Robert Fitak, assistant professor in UCF’s Department of Biology, part of UCF’s College of Sciences.
Fitak and researchers in the United Kingdom and Israel recently authored an article in Philosophical Transactions of the Royal Society B that proposes a hypothesis that the magnetic sense comes from a symbiotic relationship with magnetotactic bacteria.
Magnetotactic bacteria are a special type of bacteria whose movement is influenced by magnetic fields, including the Earth’s.
Animals that sense Earth’s magnetic field include sea turtles, birds, fish and lobsters. Sea turtles, for example, can use the ability for navigation to return to the beach where they were born.
In collaboration with experts in the United Kingdom and Israel, Professor Fitak has proposed a new theory that a symbiotic relationship with magnetotactic bacteria is what gives animals a magnetic sixth sense. These bacteria orient themselves along the lines of Earth’s magnetic field using organelles called magnetosomes that contain magnetic crystals.
The researchers not only present evidence from past studies to support their theory, but also introduce some new evidence of their own. Professor Fitak mined one of the largest genetic databases of microbes, known as the Metagenomic Rapid Annotations using Subsystems Technology database, to examine cases where magnetotactic bacteria were found to be present in animal samples.
Learning how organisms interact with magnetic fields can improve humans’ understanding of how to use Earth’s magnetic fields for their own navigation purposes. It can also inform ecological research into the effects of human modifications of the magnetic environment, such as constructing power lines, on biodiversity. Research into the interaction of animals with magnetic fields can also aid the development of therapies that use magnetism for drug delivery.
In the article, the researchers review the arguments for and against the hypothesis, present evidence published in support that has arisen in the past few years, as well as offer new supportive evidence of their own.