Parallel changes in genetic diversity and species diversity following a natural disturbance

Evanno, Castrella, Antoine, Paillat and Goudet (2009) examined variations in species and genetic diversity in a metacommunity of 16 species of freshwater gastropods living in a floodplain environment in south-eastern France during a natural disturbance. The research was conducted over a four year period, and examined the effect of a severe drought on changes in both genetic and species diversity of the gastropod communities. It was found that disturbances in the natural environment can lead to changes in genetic and community structure through the combined effects of selective and neutral processes.

Species-genetic diversity correlation (SGDC) refers to a relationship between migration, drift and selection and genetic and species diversities. Studies prior to this research have found both negative and positive relationships between environmental factors and genetic and species diversities, allowing for the current research to further investigate the influence of natural disturbances.

Radix balthica were used for genetic analysis, as this was the only species present in all bodies of water studied. The snails were collected and sampled onsite using a foot sample for DNA extraction. The researchers found striking results: both species and genetic diversities changed dramatically in parallel over a relatively short time period during which the drought occurred. The initial predictions were validated, as species- and genetic alpha diversity declined and species- and genetic beta diversity increased following the drought. Thus, it was concluded that changes in species and genetic diversity are best explained by a wide impact of natural disturbance through drift and selection at multiple levels of biodiversity.

http://en.wikipedia.org/wiki/Gastropod

http://en.wikipedia.org/wiki/Radix_balthica

http://www3.interscience.wiley.com/cgi-bin/fulltext/122207019/PDFSTART

Evanno, G., Castrella, E., Antoine, C., Paillat, G., Goudet, J. (2009). Parallel changes in genetic diversity and species diversity following a natural disturbance. Molecular Ecology, 18, 1137-1144.