From Ram Radhakrishnan:

Re: Death from across the galaxy (Feb. 27): In as much as the gamma ray beams sterilize everything on their path, it is also possible that some of the “off-axis” radiation might cause genetic mutations, positive and negative across habited planets along the way. These cones of radiation may in fact be responsible for the birth of prodigies as well as those with genetic defects. Due to lensing effects, the beams may even tighten and collimate to reach greater distances, spanning intergalactic space and reach say, planet earth, cutting a narrow swatch across the surface, drastically altering the future of those along the center line! This may even explain the “punctuated” nature of evolution here on planet earth. In the future, it may be possible through advanced GIS systems to correlate the spatial & temporal incidence of disease with known gamma ray bursts.