October 2009 Archives
While scanning several TV channels more than a month ago now, I came across a show on alternate theories of how the dinosaurs went extinct. Either on the Discovery Channel or History Channel, I can't recall which channel. The show focused on a husband and wife team, George and Roberta Poinar, who had an alternate theory on dinosaur extinction. They proposed that environmental factors (changing climate, meteor strikes) were only a portion of the reason why dinosaurs went extinct.
In their book "What bugged the dinosaurs" (Personally, I think they could have come up with a better name), they argue that insects, and diseases that they carry, could be an important factor in why dinosaurs became extinct at the K/T boundary. The K/T boundary is the Cretaceous-Tertiary boundary some 65.5 million years ago which is the point in time where scientist think most dinosaurs were either extinct or becoming extinct. Insects could have devastated food sources or caused widespread disease infestations. Evidence on the idea came from investigation of amber-encased insects that existed at the K/T boundary and comparisons with insects that currently exist and cause widespread disease. By viewing blood cells with the amber-encased insects, they were also able to identify several vector-borne diseases.
The authors compared their findings with disease infestations found today in amphibians. They propose that the same process that affected the dinosaurs may be playing out in from of our eyes. As global temperatures rise slightly, disease agents become more virulent as seen with the rise of fungal diseases, such as the chytrid fungus, causing extinction and decline in amphibian populations.