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We use electromagnetic communication everywhere these days. Cell phones, wifi, old-school radio transmissions, television, deep space communication, etc.

I'm curious about some of the possible reasons we have never seen biological systems having evolved to use electromagnetic, i.e. radio, for communication. The one obvious exception to this are organisms that generate their own light, i.e. bioluminescence. Cuttlefish are masters of this, and many other species as well.

It seems like bio-radio could have offered all kinds of evolutionary advantages for animals capable of using it.

Are their basic physical limits in chemistry, or excess energy requirements or something that would basically have made this impossible? Or was this perhaps just something that life never evolved to use, but would otherwise be possible in evolution?

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  • $\begingroup$ Also, don't forget magnetotactic bacteria $\endgroup$
    – nico
    Commented Aug 15, 2012 at 8:07
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    $\begingroup$ Light is an electromagnetic wave. The only difference is wave length and energy. $\endgroup$
    – Konrad Rudolph
    Commented Aug 15, 2012 at 21:03
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    $\begingroup$ What about Sharks? $\endgroup$
    – Armatus
    Commented Aug 16, 2012 at 8:17
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    $\begingroup$ Life did evolve to use radio, we use it all the time. $\endgroup$
    – john-jones
    Commented Aug 19, 2012 at 8:58
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    $\begingroup$ See electrocommunication, weakly electric fish and Mormyridae. They use 500 Hz electric sine signals (however, AFAIK using conductance of water, not - electromagnetic waves). $\endgroup$
    – Piotr Migdal
    Commented Aug 21, 2012 at 20:06

5 Answers 5

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There is a very different mechanism for generation (and detection) of ultraviolet, visible and infrared light vs radio waves.

For the first, it is possible to generate it using chemical reactions (that is, chemiluminescence, bioluminescence) with a typical energy of order of 2 eV (electronovolts). Also, it is easy to detect with similar means - coupling to a bond (e.g. using opsins).

For much longer electromagnetic waves, and much lower energies per photon, such mechanism does not work. There are two reasons:

  • typical energy levels for molecules (but it can be worked around),
  • thermal noise has energies (0.025 eV) which are higher than radio wave photon energies (<0.001 eV) (it rules out both controlled creation and detection using molecules).

In other words - radiation which is less energetic than thermal radiation (far infrared) is not suitable for communication using molecular mechanisms, as thermal noise jams transmission (making the sender firing at random and making the receiver being blind by noise way stronger than the signal).

However, one can both transmit, and detect it, using wires. In principle it is possible; however, without good conductors (like metals, not - salt solutions) it is not an easy task (not impossible though).

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    $\begingroup$ Why is the thermal noise not a problem in mechanical devices then? Is the only reason the better conductivity of the material? $\endgroup$
    – Konrad Rudolph
    Commented Aug 15, 2012 at 21:05
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    $\begingroup$ Thermal noise is devastating for molecular devices, as detectors/emitters (two-level systems) are all the time saturated (so e.g. a photon has the same probability of being absorber and to steal excitation). For macroscopic currents there is no such mechanism and one can easily go beyond the thermal noise (so for animals its only a technical problem of getting good enough conductors and generators of high frequencies). Moreover, AFAIK water absorbs most of radio waves (it's why submarines use sonars, not - radars), so radio communication would work only for land animals. $\endgroup$
    – Piotr Migdal
    Commented Aug 16, 2012 at 12:07
  • $\begingroup$ Wires (like tubules, axons) for electrical signaling seem to be very common in the cell world. Is it actually known that they don't have a radio wave antenna function too? $\endgroup$
    – LocalFluff
    Commented Jun 16, 2015 at 21:08
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    $\begingroup$ @LocalFluff Axons are not "wires". They propagate signal due to depolarization, not - conductance. $\endgroup$
    – Piotr Migdal
    Commented Jun 17, 2015 at 8:22
  • $\begingroup$ Okay, I'm lost in this weird universe of microbiochemo whatever. Fascinating stuff. But there are plenty of microtubules around, up to a couple of millimeters long. Life seems to like to make tubes and strings of different kinds. My wild thought is that maybe they could generate and react to radio waves? Some speculate that they might even have quantum mechanic properties. Water is bad for radio, but on the scale of a few cells maybe that doesn't matter much. $\endgroup$
    – LocalFluff
    Commented Jun 17, 2015 at 9:09
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Because the intermediate stages are not evolutionarily favoured. That's why.

Sound and light perception are useful without any generative capability. An organism with a tiny amount of perception for either of these things has an advantage over those without; and an organism with a tiny amount more has an advantage over those with a tiny bit less. This advantage forms the basis for selection and thus improved sensory capabilities (balanced, of course, by the cost of those capabilities).

Being able to perceive radio on the other hand provides no useful information about the world at low level perception so even if an organism was to randomly mutate so as to detect radiowaves* there would be no selection for this ability, and thus no mechanism to drive the evolution of advanced radio reception. Without the ability to perceive radiowaves there is no possibility of evolving the ability to generate radio signals in a controlled manner.

*-In fact, since radiowaves generally interact very little with organic materials unlike heat, light and sound even this first step of random mutation is much less likely than for sense that have evolved.

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    $\begingroup$ I find the "intermediate stages" along with "no useful information about the world" argument more satisfactory than thermal noise argument. Terrestrial animals preferred visible light to be visible because of Sunlight spectrum. en.wikipedia.org/wiki/File:Solar_Spectrum.png Sound has high attenuation, so it is more fit for local communication without attracting predators from long distance. $\endgroup$
    – Vikas
    Commented Jan 22, 2014 at 17:56
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    $\begingroup$ How about bats? Their ecolocation is useful without any transmitter. $\endgroup$
    – Dan Dascalescu
    Commented Jan 31, 2015 at 20:58
  • $\begingroup$ @DanDascalescu: (1) What do you mean there is no transmitter? Bats create the sound they listen for echoes of and (2) Bats' echolocation works by further evolution of the already-selected-for abilities to hear and make sounds. $\endgroup$
    – Jack Aidley
    Commented Feb 1, 2015 at 11:36
  • $\begingroup$ @JackAidley, I meant without another transmitting animal. $\endgroup$
    – Dan Dascalescu
    Commented Feb 2, 2015 at 11:07
  • $\begingroup$ @Vikas Multicellular organism have many cells which communicate with each other, using many complicated chemical and electrical signals. The first multicellular individual that somehow mutates to use radio could certainly benefit from it. All cells in it would then have the same genes, the same radio channel. $\endgroup$
    – LocalFluff
    Commented Jun 16, 2015 at 19:54
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Actually, electromagnetic communication is used by certain fish, the mormyrids and the gymnotids. Pulse modulated in the former and amplitude modulated in the latter.

However, the frequencies used are not much greater than 1Khz, which is not what we ordinarily consider to be in the radio frequency spectrum.

There is, too, another biological species in which the use of the full RF spectrum has evolved. Its activities even extend to the use of the UV and X-ray frequencies.

That species is our own. I am not being flippant here. We must not fall into the trap of considering ourselves as apart from nature. Contrary to our usual intuitions, technologies have evolved autonomously within the collective imagination of our species.

The broader evolutionary model which supports this contention is outlined, very informally, in "The Goldilocks Effect: What Has Serendipity Ever Done For Us?" , a free download in e-book formats from the "Unusual Perspectives" website.

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    $\begingroup$ Thanks for the info about mormyrids and gymnotids. I'll do some further reading on them. I am only interested in biologically-generated radio communication, which was where my question was directed. One of the key differences between technology and biology is that the former is not inherently inheritable. A flock of birds that communicate via radio will pass that ability to their young and is innate. Human speech capability is passed innately to our young. The knowledge to build technology is sociological, not biological. $\endgroup$
    – Geuis
    Commented Aug 18, 2012 at 22:13
  • $\begingroup$ You miss my point. The evolution of technology cannot be dismissed as "sociological". If examined carefully is ti an inevitable outcome of biology. It is so very easy to fall into that anthropocentric trap. The mechanisms of transmission are, of course, not identical for the various phases of the overall life process. $\endgroup$
    – Peter Kinnon
    Commented Aug 19, 2012 at 4:24
  • $\begingroup$ this is a good answer - adaptation could, given proper conditions, create radiosensitive organisms I'm sure. $\endgroup$
    – shigeta
    Commented Aug 19, 2012 at 9:49
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I just found a research about possibility of organism with loop DNA (Mostly bacteria) could use there DNA as antenna to transmit and receive radio wave around 1kHz

http://www.wired.com/2011/04/bacterial-radio/

But as other said. Communication mostly evolve from sensory organ. So the radio wave has too much noise and could not give useful information about situation. They don't selectively evolve to the point that they could be used to communicate

But the bacteria has inherently possibility from start. So they may actually do some communication

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  • $\begingroup$ That's really interesting! Thanks for the update. $\endgroup$
    – Geuis
    Commented Jul 13, 2015 at 23:04
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A quick comparison between light and sound vs. Radio

  • Light: Wavelength 380 nm -740 nm
  • Sound: 17 mm - 17 m
  • Radio: 1mm - 10e5 km

EM spectrum

From the Planck relation, the energy of a wave is inversely proportional to the wavelength. As a result light is stronger than sound which is stronger than FM radio which is stronger than AM radio. Very likely, the energy density provided by radio is far too weak to have meaningful signal processing.

However, there are some uses in the radio frequency. Bat echolocation occurs at a frequency of 14,000 to 100,000 Hz which is well within the radio frequency.

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  • $\begingroup$ You don't need a lot of energy to communicate anything. Anyway, radio and wifi works, so it's not a good argument. $\endgroup$
    – Piotr Migdal
    Commented Aug 15, 2012 at 12:15
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    $\begingroup$ @PiotrMigdal, I agree with that counterargument. However, electronic forms of communication via Radio and wifi have the luxury of being amplified. Yes, signaling cascades exists but certainly are not optimal compared to higher frequency channels. Your answer is certainly better. $\endgroup$
    – bobthejoe
    Commented Aug 16, 2012 at 5:43
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    $\begingroup$ A good point with amplification. For radio you want sine-wave amplifiers, not cascade amplifiers, so here there may be a problem as well. However, the first step is to have good wires... $\endgroup$
    – Piotr Migdal
    Commented Aug 17, 2012 at 10:12
  • $\begingroup$ echolocation uses sound not light. the mechanism for detecting sound is basically the same regardless of frequency while light has to change significantly across that difference. the detection of sound can lead to the detection of high frequency sound but an eye cannot be made to detect radio without significant changes at every level. $\endgroup$
    – John
    Commented Aug 18, 2018 at 14:04

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