Monday, October 12 7:00 pm
1320 Digital Computer Lab
1304 W. Springfield
2009 marks not only the 200th anniversary of Darwin’s birth but also publication of the first evolutionary theory, Lamarck’s Philosophie Zoologique. “Lamarckian evolution” is usually distinguished from “Darwinian evolution” by its reliance on the inheritance of acquired characteristics, and as such, is usually dismissed as lacking a sound biological basis. However, there is increasingly compelling evidence for a variety of molecular mechanisms that can support Lamarckian modes of evolution. In this talk, I will discuss our recent work with pond organisms, known as ciliates, demonstrating an extraordinary new role for the molecule RNA. Normally thought of as a conduit in gene expression, in ciliates, RNA can provide both an organizing role in DNA rearrangements and a template for transmitting mutations to the next generation. Understanding how information is encoded to reorder genome fragments highlights the deep connections between computational and genomic processes. I explain how a transiently-expressed cache of non-coding RNAs may provide the programming instructions for genome remodeling and transmit heritable information. The occasional transfer of point mutations from these RNA templates to rearranged DNA molecules supplies a viable mechanism for stable inheritance of acquired characters. This mechanism for inheritance beyond the conventional DNA genome can pass information across multiple generations, hinting at the power of RNA molecules to reshape genome information.
