A Critical Review

Happy Hyperdisease!

I may seem a little excited posting so soon after my last blog, but since it’s Halloween I felt that this would be the perfect time to talk about hyperdisease. So today we will have a brief critical review of the subject!

Beginning at around 50,000 years ago, until quite recently, most large land animals began to significantly decrease in numbers before becoming extinct (Koch and Barnosky, 2006; Stuart, 1999). One rather controversial explanation of this is the hyperdisease hypothesis. 

Extinct species of late-Pleistocene (white), alive in 20th Century (grey).

(Stuart,1999 p.258)

What is Hyperdisease?

Effectively, the idea is that hyperdisease was brought into North America by humans. That it could be passed widely and between species, and caused mass loss of megafauna. The implication being that this would spread around the globe and cause a mass extinction (MacPhee and Sues, 1999).

Evidence?

There is some support for this in the area of North America. Tuberculosis was found present in large quantities of Mastodon (Mammut americanum). Almost one quarter of 113 examined individuals showed signs of the disease (Rothschild and Laub, 2006). So, in North America it may have played a part in extinction.

Problems (e.g. many)

There are several problems with this:

1. There is really no solid evidence of this in Europe.
2. The Mammoths were not affected (Rothschild and Laub, 2006).
3. This hypothesis would not fit with the pattern of megafauna extinction in Europe (MacPhee and Sues, 1999).

This has been a rather brief summary of hyperdisease, which I believe (with the current evidence) can be put to rest for the area of Europe. In North America this may well have contributed to megafauna decline, but in Europe there is really no tangible evidence (at least that i can find)! Soon we will have a more detailed discussion on the migration of animals in and out of Europe over earlier glacial cycles, specifically hippos!

P.S..

If you have not followed the hyperdisease link then i suggest you check it out. This is the blog it takes you to, nice summary if you are interested in what was happening in North America.

LINK

Worth a read!