Paul Nelson & Jonathan Wells Take Their Case to the Society for Developmental Biology Annual Meeting
Next week, the Society for Developmental Biology (SDB) will be holding its 2011 annual meeting in Chicago. Paul Nelson and Jonathan Wells, both SDB members, will be presenting posters designed (pun intended) to provoke discussion. Both Paul and Jonathan hope any SDB members who read this will stop by their posters to talk.
Jonathan is up first, and will present his poster at the Saturday, July 23 session, from 12:30-2:00 pm, at the Riverside Center West facility of the Hyatt Regency. Here's his abstract:
Gene Regulatory Networks in Embryos Depend on Pre-existing Spatial Coordinates
The development of metazoan embryos requires the precise spatial deployment of specific cellular functions. This deployment depends on gene regulatory networks (GRNs), which operate downstream of initial spatial inputs (E. H. Davidson, Nature 468 : 911). Those initial inputs depend, in turn, on pre-existing spatial coordinate systems. In Drosophila oocytes, for example, spatial localization of the earliest-acting elements of the maternal GRN depends on the prior establishment of an anteroposterior body axis by antecedent asymmetries in the ovary. Those asymmetries appear to depend on cytoskeletal and membrane patterns rather than on DNA sequences, and there is evidence that some cytoskeletal and membrane patterns can be inherited independently of the DNA. I review that evidence, suggest that such patterns provide developmental information that must precede the operation of GRNs, and discuss possible implications of that information for evolutionary theory.
Paul presents the next day, Sunday, July 24, from 2:00-3:30 pm, also at the Riverside Center West. Paul's abstract:
Did Natural Selection Construct Metazoan Developmental Sequences?
The necessary and sufficient conditions of the process of natural selection (Endler, Natural Selection in the Wild, 1986) are (1) variation, (2) selection or fitness differences, and (3) inheritance. These conditions impose evidential demands on any investigator who wishes to employ natural selection in evolutionary (i.e., historical) explanation. Data from model systems (e.g., C. elegans, Drosophila, and Danio), as well as theoretical analyses, raise challenges for the use of natural selection as the causal process responsible for the origin of developmental sequences. In particular, the conditions of (2) selection differences and (3) inheritance have not been adequately described in current theories of the evolution of the Metazoa.
Say hello if you're at the meeting.