Study Shows How Biodiversity Can Protect Against Disease

The findings of a recent study, published in the journal Nature on February 14th, supports the idea that greater biodiversity in large-scale ecosystems may also provide greater protection against diseases. As an example, it is supposed that from large numbers of mammals to large numbers of bird species, ecosystems show the curb of cases such as Lyme disease and the Nile Virus respectively.

The new CU-Boulder study used easy-to-sample ecosystems by visiting hundreds of ponds in California, while recording the types of amphibians living there. As well as this, the biologists recorded the number of snails infected by the pathogen Ribeiroia ondatrae. Spending three years to sample 345 wetlands, the team's results showed that ponds with half a dozen amphibian species had a 78% decline in parasite transmission compared to the ponds with just one amphibian species.

The reason for the reduction in these parasitic infections as the biodiversity of an ecosystem increases may most likely be related to the fact that amphibian species in ponds are added in a predictable pattern. In this case, the first of the species to appear is the most susceptible to infection, while later species appear to be the least prone.

As according to assistant professor Pieter Johnson, the lead author of the study, "[o]ur results indicate that higher diversity reduces the success of pathogens in moving between hosts. Nonetheless, if infection pressure is high, [...] there will still be a significant risk of disease; biodiversity will simply function to dampen transmission success"  (Pieter).

NOS Themes:

Science is based on evidence; scientists gathered data on more than 345 wetlands, using those findings as evidence to conclude their study.

Importance of repeatability; scientists sampled hundreds of ponds in California, as well as creating various artificial ponds repeatedly in order to obtain the most accurate data.

The role of motivation and curiosity; the reason why this study was conducted was because scientists were curious as to the effects of biodiversity on the protection against disease.

http://phys.org/news/2013-02-biodiversity-disease.html

Adrianna Tan
Hour 3