Tuesday, January 8, 2008

Disease and flowers own the Dinosaurs?

This World Science page article introduces the most recent work of George Po­inar Jr. of Or­e­gon State Un­ivers­ity and his wife Ro­ber­ta, which suggests that insects, climate and the spread of flowering plants had much to do with the disappearance of the Dinosaurs during and after the K-T boundary. Their book “What Bugged the Di­no­saurs? In­sects, Dis­ease and Death in the Cre­ta­ceous” doesn't completely discount the effects of massive meteor impacts (the most popular theory today regarding the disappearance of the dinosaurs), but say that there were more problems for the Dinosaurs than that -- namely insect-borne pathogens. One telling point is that not all the Dinosaurs disappeared right after the big impact marking the K-T boundary, many lived thousands of years longer, including those that eventually evolved into birds.

The environment was very tropical during this time period, and this combined with the spread of flowering plants led to an enormous radiation of insect life. These are good conditions for diseases of all kinds, not the least of which being blood-borne pathogens spread by insects, like Malaria and Leish­ma­ni­a.

[photo credit in original linked article]

Enjoy your cold, bug-less winters,



Stu Farnham said...

The authors speak of more than insect-borne disease. They also point out that the increase in insect populations went hand-in-hand with a shift to flowering plants (my understanding is that the vegatation up until the end of the cretaceous consisted largely of Pteridophylia (ferns & horsetails, Latin provided for BPaul's enjoymnet) and the so-called fern allies, Lycopodialis (club mosses, quillworts, ground cedars). The decline in their food species may also have accounted for the decline of the dinosaurs.

Another theory has to do with a less abrupt climate change. The dominant climate cooled considerably following the Cretaceous period, and the cold blooded dinosaurs were displaced by warm-blooded species (birds are warm blooded -- if there are exceptions I am unaware of them). The smaller reptiles that survived did so either because strategies such as burrowing and the metabolic slowdown that many colder-climate reptiles experience in winter.

Enjoy your coming extinction, you've earned it!

Bpaul said...

Your "enjoy" endings are hilarious today, weirdo.

Stu Farnham said...

We endeavour to provide satisfaction, sir.

Enjoy your British humourists.