In many ecologies organism exchange of metabolites in a process known as cross-feeding, which leads to complex dependencies
on fitness. We have created an artificial ecology called Urdar (after the well where the norse universe, i.e. the ash tree Yggdrasil
was growing) in order to study cross-feeding in a highly controlled experimental yet digital environment. We will discuss three
questions in relation to this system: i) Is a cross-feeding ecology with a higher nutrient influx be more or less diverse? ii) Will a
cross-feeding population converge towards an optimal configuration with respect to the overall productivity? iii) What can be
said about the dynamics of three cross-feeding species if pairwise interactions are known?