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Bioelectromagnetism

 

Joseph Kirschvink is skeptical about the idea that increased dosing of living organisms with

UV radiation is a direct result of the decreased GMF (Randall, 2016). Although this idea is long-

established, its efect on the evolution of life at this time should be limited, and as the radiation would

not be able to reach and damage the germline, the cells of the body used in sexual reproduction to

pass genetic information to ofspring (Randall, 2016). Te radiation would afect the outer skin but

the germ cells are usually internal and protected (Randall, 2016). As such, he argues that the idea that

increased levels of UV radiation signifcantly afected the evolution of life in the Ediacaran is prob­

lematic (Randall, 2016).

Niitsuma and Fujii (1984) examined the foraminiferal fossil assemblages at the boundary around

730 ka during Chibanian on the Boso Peninsula. As a result, it was found that the planktonic foramin­

ifera fossil assemblages decreased during Chibanian, and that the decrease was larger in the surface

layer. Tis is because the geomagnetosphere became unstable due to GMF reversals, charged particles

from the solar wind rushed into the upper atmosphere and destroyed the O3 layer, and thus increasing

the amount of potentially harmful UV-B reaching the Earth’s surface. Terefore, it is inferred that a

large number of organisms on the ground and on the ocean surface died.

However, Aubert et al. (2010) argued that only small changes that occurred in the GMF were too small

to have major efects on the geomagnetosphere shielding efciency since the early Earth. In another

aspect, it has been reported that the most abundant and readily available radiation shield is water

(Simonsen and Nealy, 1991), and the shielding efects of water on UV-B (280–315 nm) radiation is also

important (Tedetti and Sempéré, 2006).

Tese hypothetical reports are very intriguing, but the synchronization that the geomagnetic esca­

lation and the mass extinction of species occurred at the same time has not clarifed the relationship

between the two events, and eventually, the increase in UV radiation may not have led to the mass

extinction (Suganuma, 2020). Tus, it seems likely that many researchers are skeptical about this

hypothesis (Suganuma, 2020). In addition, it is speculated that the frequency of GMF reversals occurred

much more frequently than that of catastrophic extinctions. Tere were certainly GMF reversals that

occurred almost at the same period as the catastrophic extinctions, but in most other cases it had noth­

ing to do with the catastrophic extinctions. It is supposed that there is no statistical correlation between

GMF reversals and extinctions.

Regarding the direct impact of the GMF on life and humans on Earth, it is impossible to predict

exactly what will happen because humans did not exist at the time of the last complete GMF reversal.

Whether or not the GMF reduction is directly related to human extinction, it is predicted that humans

do not have to panic about the GMF reversals and the GMF reduction. Tis is because there is no evi­

dence that disasters have occurred even afer the weakening of the GMF several times in the past, and

if there are disasters, it may afect the electric power system or there may be an increase in patients with

some diseases related to reduce the GMF intensity. It implies that there is no need to think directly about

the extinction of humans.

It has been considered that the existence of the GMF is indispensable for the origin and evolution

of life. Te GMF plays a crucial role in shielding harmful charged particles and GCRs. It is predicted

that the magnetic pole may be moved and exchanged, and the GMF reversal transition can occur unex­

pectedly in a short time scale. Tis GMF reversal transition weakens the GMF and might increase the

frequency of mutations caused by the stronger solar wind and GCRs. At the individual level, mutations

can cause carcinogenesis, dysfunction, etc., and can be detrimental to survival. However, at the popu­

lation level, mutations can create individuals with new morphologies and functions, which may be a

driving force for evolution. In the future, by improving the accumulation of paleomagnetic records and

the accuracy for their analysis technology, and the accuracy for the determination of the period of the

extinction and evolution of life on Earth, the efects of not only geomagnetic excursions but also GMF

reversals, which are more dynamic GMF fuctuations, on the extinction and evolution of life on Earth

will be clarifed.