This short print article from National Public Radio (NPR) reports on recent research indicating that die-offs of large mammals occurred in periods when the Earth's magnetic field was weak. Giant kauri trees in New Zealand, which lived through the last reversal of Earth's magnetic field, were studied to make a detailed record of the timing of magnetic field changes. The researchers findings indicated that a pole reversal occurring 42,000 years ago could be correlated to a die-off of large mammals on Earth and to appearance of cave dwellings among Neanderthal populations. The researchers suggest that this pole flip resulted in hominids seeking cave shelter to avoid the damage of ionizing radiation (resulting from Earth's magnetic field change).

This article was a summary of research published in the journal Science, Vol. 371, 6531, A global environmental crisis 42,000 years ago, Cooper, Turney et al, pp. 811-818.