UNIVERSITY OF HERTFORDSHIRE
		 COMPUTER SCIENCE RESEARCH COLLOQUIUM

			      presents

               "Genotype-Phenotype Maps and their impact on 
              Differentiation in Genetic Regulatory Networks"

			    Johannes Knabe 
		      (School of Computer Science,
		      University of Hertfordshire)


			21 February 2007 (Wednesday)

			  Lecture Theatre E351
		       Hatfield, College Lane Campus
			       3 - 4 pm

	       Coffee/tea and biscuits will be available.
			  [Catering Permitting]

		    Everyone is Welcome to Attend
			  [Space Permitting]



Abstract:


We investigate the evolvability of artificial Genetic Regulatory
Networks (GRNs) for differentiation.  The proposed GRN model supports 
non-linear interaction between regulating factors, thereby facilitating 
the realization of complex regulatory logics. GRNs of this kind are 
evolved to follow different pathways, producing different kinds of 
periodic dynamics in response to minimal differences in external 
stimulation. Changing the environment over evolutionary time, allowing 
a lineage to adapt gradually to demands for differentiation is found 
to yield better results on average than static environments with 
pressure for differentiation from the beginning.
Furthermore the impact of the degree of smoothness with which genotypic
variation is mapped to phenotypic variation on the evolvability of
differentiation is discussed. Various genetic operators and GRN model
versions are taken into consideration. A main result shows that for
evolutionary search spaces of increasing sizes evolved performance
drops much more strongly in the traditional network model where mutations
change edges as compared to a more realistic model where the strength
of influences between nodes is shifted.

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Hertfordshire Computer Science Research Colloquium
http://homepages.feis.herts.ac.uk/~nehaniv/colloq