Apr. 4, 2008 Birds and bees may do it, but the microscopic
animals called bdelloid rotifers seem to get along just fine
without sex, thank you. What’s more, they have done so over
millions of years of evolution, resulting in at least 370
species. These hardy creatures somehow escape the usual drawback
of asexuality – extinction – and the MBL’s David Mark Welch,
Matthew Meselson, and their colleagues are finding out how. In
two related papers published recently in Proceedings of the
National Academy of Sciences (PNAS), the team proposes an
interesting hypothesis: Bdelloid rotifers have been able to give
up sex and survive because they have evolved an extraordinary
efficient mechanism for repairing harmful mutations to their
DNA. “We think, in the bdelloid rotifer, genomic changes
together with environmental changes have conspired to create
something that is able to exist in the absence of sex,” says
Mark Welch, an assistant scientist in the MBL’s Josephine Bay
Paul Center. Their results have medical implicatio