2 Nov 2016– Parasites and their hosts often have a positive relationship. First as the hosts grow and change, so do the parasites that rely on them. This is according to the Journal of Parasitology, Vol. 102, No. 5, 2016.

According to Researchers from the University of Michigan and University of Colorado Boulder parasites depend on their hosts, and the number of parasite species grows as hosts evolve into new, distinct species. More hosts mean more niches and ultimately more parasite species.

According to the researchers of the study, the missing key to how this diversity increases is the idea of spatial scale. Space refers not just to the boundaries of a study area but also to the opportunities for individuals to interact.

“Individual studies have tested ‘diversity begets diversity’ at extremely divergent spatial scales, but no attempt has been made to integrate the concept of spatial scale into theory supporting this hypothesis,” says Chelsea Wood, corresponding author of the article. She and co-author Pieter Johnson suggest that focusing on space could make it easier to understand the extent to which host richness relates to parasite richness.

Studying how many parasite species are added for each host species could help researchers estimate the number of parasite species on Earth and learn more about disease risk and spread.

Wood adds that the paper is the first to integrate the problem of spatial scale into theory on how host and parasite diversity are linked. The paper argues that to better understand the diversity relationship between host and parasite, researchers need to test different data in new ways. A new study that looks at the diversity of a single parasite and its host across spatial scales could provide many of the missing answers.(contact cziegler@allenpress.com)