Somatic mutation and the Antarctic ozone hole

1.

Previous studies of Antarctic clonal moss populations using RAPD markers have reported

extraordinarily high levels of genetic variation. This has been claimed to reflect somatic mutation,

possibly resulting from elevated UV-B radiation.

2.

Our study used microsatellite markers to compare the genetic variation present within continental

Antarctic, sub-Antarctic and temperate populations of the moss

Ceratodon purpureus

.

3.

In contrast to the RAPD studies, microsatellite data revealed that

C. purpureus

populations from

continental Antarctica display less intra-population genetic diversity than populations from a

range of temperate and sub-Antarctic sites.

4.

Analysis of molecular variation (

amova

) revealed that populations within the Windmill Islands

region of Antarctica were more genetically differentiated than populations spread among more

widely separated temperate regions.

5.

Synthesis

. Our data provide no evidence of elevated mutation rates in the Antarctic, and imply

climate change will present ongoing challenges for continental Antarctic moss populations that

appear weakly interconnected and with less potential than temperate populations to adapt to

environmental change.