ZEN: Eco-evolutionary Software

Figure 1

Deployment of polymorphism in a population subjected to asymmetric competition
(ZEN simulation, model from Kisdi & Geritz 2001).
The distribution of phenotypes is shown along evolutionary time in ordinates.

Ecology

Ecological models with an evolutionary component allow to study several biological phenomena: host-pathogens interactions, coevolution of plants and pollinisators, mimicry, development of the immune system, evolution of cooperation, evolution of life history traits, and more generally biodiversity and speciation.

What is simulated by ZEN ? The evolution of populations under the mutation-selection process 

ZEN uses an individual-based (in fact ‘phenotype-based’) approach with 3 components:

• Stochastic equations in discrete time describing the dynamics of finite populations
• Adaptive traits and their mutations (mutation rates and distributions)
•  Ecological interactions between phenotypes

During the ZEN simulation, mutant phenotypes created by the triggering of mutations interact with resident phenotypes. They persist or go extinct, possibly leading to evolutionary branching and polymorphism (Figs. 1, 2).

How does ZEN work ?

Models are described in a text file using a reduced declaration language, and studied by means of a simple interface with convenient graphics. The ZEN kernel is a symbolic evaluator handling ‘polymorphic’ variables.

More information here