The electrical activity inside humans and other animals is eerily similar to the electrical fields observed in the Earth's atmosphere, according to a team of researchers.
In a study published in the journal International Journal of Biometeorology, the scientists say they have found a link between atmospheric electric fields and electrical activity seen in many different living creatures on our planet.
"We show that the electrical activity in many living organisms—from zooplankton in the oceans, to sharks and even in our brains—is very similar to the electrical fields we measure and study in the atmosphere from global lightning activity," Colin Price, lead author of the study from the Porter School of the Environment and Earth Sciences at Tel Aviv University, Israel, said in a statement.
In animals, electrical activity can be observed in the nervous system. These electrical signals travel throughout the body controlling all manner of biological functions. Most of this electrical activity in vertebrates and invertebrates occurs at extremely low frequencies, with a maximum of 50 hertz (Hz.)
The fact that many different types of species display similar low frequency activity, irrespective of differences in brain size and complexity, is surprising, the researchers say. However, the reasons for why organisms exhibit characteristic extremely low frequency electrical activity has long remained a mystery. Furthermore, it is not clear why this electrical activity displays similarities to electrical activity in the atmosphere.
"Neither biologists nor doctors can explain why the frequencies in living organisms (0-50 Hz) are similar to those in the atmosphere caused by lightning," Price said. "Most of them are not even aware of the similarity we presented in our paper."
There have been relatively few studies on the origin of the low frequency electrical activity. And so the authors wanted to address this gap in our knowledge with their latest study research.
To do this, they conducted a review of previous studies looking into the link between extremely low frequency (ELF) electric fields in the atmosphere—radio waves with frequencies ranging from 3 to 30 Hz that are generated by lightning and natural disturbances in Earth's magnetic field— and the health of animals, including humans.
In light of this review, the researchers propose that over billions of years—as organisms evolved on Earth—the natural electromagnetic frequencies in the atmosphere generated by lightning activity significantly influenced the development of electrical activity in biological cells. They say it is likely that this influence was greater in the early stages of evolution when species tended to be relatively simple and primitive.
"We hypothesize that over evolutionary timescales living organisms adapted and evolved to actually use the electricity in the environment—global lightning," Price said. "This has likely not changed over billions of years and is similar to the evolution of our eyes, which evolved using the sunlight nature gave us."
According to the authors, the latest results could have implications in the field of medicine, given that diseases such as epilepsy and Parkinson's are linked to abnormalities in the electrical activity of the human body.
"Our review of previous studies revealed that lightning-related fields may have positive medical applications related to our biological clock, spinal cord injuries and maybe other bodily functions related to electrical activity in our bodies," Price said. "The connection between the ever-present electromagnetic fields, between lightning in the atmosphere and human health, may have huge implications in the future for various treatments related to electrical abnormalities in our bodies."
The researchers note that while the studies they reviewed provide evidence that electrical activity in the atmosphere influences biological processes, a physical mechanism to explain the findings is still lacking. Thus more studies need to be conducted into the issue they say.
"Going forward, we need to design new experiments to see how these extremely low frequency fields from lightning may impact living organisms, and to investigate how these fields can be used to benefit us. One new experiment we are now planning is to see how these fields may impact the rate of photosynthesis in plants," Price said.