Title:
An Archean Origin of Earth's Magnetic Biosphere: From the magnetotactic bacteria to the human brain.

Abstract:
Recent discoveries of the diversity of the magnetotactic
bacteria now constrain the origin of magnetotaxis to be prior to the
evolutionary split of the Proteobacteria and Nitrospirae, placing this
evolutionary event most likely between 3.5 and 3 Ga, near the root of the
Bacterial Domain. Hence, the last common ancestor of all bacteria was most
likely magnetotactic, with many of their descendants loosing this trait as
they moved into environments in which magnetotaxis was not selected for.
Earth's magnetic field must have been continuously present from mid Archean
time forward, with no long intervals since then with surface field
intensities < ~ 6 uT (compared with ~ 50 uT today). This is a major
contribution to ELSI's goal of connecting the evolution of Earth and Life.

Further, the existence of primitive magnetotactic Protozoa (Protists)
containing hundreds to thousands of magnetosomes argues that this bacterial
trait was transferred to the early Eukaryotic cell via endosymbiosis,
perhaps via the alpha-proteobacterium which became the ancestral
mitochondria. In any event, magnetite-based magnetoreception is common in
the Animal phyla, providing homing and migratory animals a much-needed
navigational tool to find their way.

Recent work by my group has demonstrated that humans also retain this
ancestral magnetic sensory system, albeit in a pre-conscious form. We have
discovered two rotations of earth-strength magnetic fields that elicit a
pronounced drop in brainwave activity in the alpha-wave band (8-13 Hz),
showing that environmentally-relevant changes in the local geomagnetic
field are being perceived and processed by the human brain. Two simple
tests rule out any form of electrical induction or quantum chemistry as the
biophysical transduction mechanism, but a pulse-remagnetization experiment
- effective only on magnetite-based sensory systems - has a profound
effect. Hence, humans share over 3 billion years of membership in Earth's
Magnetic Biosphere.

ELSI-WPI is at a critical juncture, facing a competitive 5-year extension
of its existence. In the lingo of 'nuclear reactions' used at the WPI site
visit last month, the discovery of the human magnetic sensory system is not
just interdisciplinary "Fusion", it is is the more energetic "Fission"
(think A-bombs vs. H-bombs). To compete with the WPI renewal, we need
discoveries that transcend the narrow boundaries formally defined by the
ELSI road map, that can make Humanity more lasting and durable. I will
discuss implications of the human magnetoreception discovery that are
directly related to our Civilization's use of electromagnetism, including
potential problems with the AM radio band and Magnetic Resonance Imaging