Evolving Synaptic Plasticity with an Evolutionary Cellular Development Model

Since synaptic plasticity is regarded as a potential mechanism for memory formation and learning, there is growing interest in the study of its underlying mechanisms. Recently several evolutionary models of cellular development have been presented, but none have been shown to be able to evolve a range of biological synaptic plasticity regimes. In this paper we present a biologically plausible evolutionary cellular development model and test its ability to evolve different biological synaptic plasticity regimes. The core of the model is a genomic and proteomic regulation network which controls cells and their neurites in a 2D environment. The model has previously been shown to successfully evolve behaving organisms, enable gene related phenomena, and produce biological neural mechanisms such as temporal representations. Several experiments are described in which the model evolves different synaptic plasticity regimes using a direct fitness function. Other experiments examine the ability of the model to evolve simple plasticity regimes in a task -based fitness function environment. These results suggest that such evolutionary cellular development models have the potential to be used as a research tool for investigating the evolutionary aspects of synaptic plasticity and at the same time can serve as the basis for novel artificial computational systems

Evidences that human disturbance simplify the ant fauna associated a Stachytarpheta glabra Cham. (Verbenaceae) compromising the benefits of ant-plant mutualism

Interaction among species, like ants and plants through extrafloral nectaries (EFNs), are important components of ecological communities’ evolution. However, the effect of human disturbance on such specific interactions and its ecological consequences is poorly understood. This study evaluated the outcomes of mutualism between ants and the EFN-bearing plant Stachytarpheta glabra under anthropogenic disturbance. We compared the arthropod fauna composition between two groups of twenty plant individuals, one in an area disturbed by human activities and one in a preserved area. We also check the plant investment in herbivory defense and the consequential leaf damage by herbivore. Our results indicate that such disturbances cause simplification of the associated fauna and lack of proper ant mutualist. This led to four times more herbivory on plants of disturbed areas, despite the equal amount of EFN and ant visitors and low abundance of herbivores. The high pressure of herbivory may difficult the re-establishment of S. glabra, an important pioneer species in ferruginous fields, therefore it may affect resilience of this fragile ecological community.As interações entre espécies, como por exemplo formigas e plantas através de nectários extraflorais (NEFs), são importantes componentes na evolução das comunidades. Entretanto, pouco é conhecido sobre os efeitos dos impactos antrópicos em interações específicas e suas consequências ecológicas. Este estudo avaliou os resultados do mutualismo entre formigas e NEF em Stachytarpheta glabra em área impactada pela atividade humana. Nós comparamos a composição e estrutura da fauna de artrópodes, em quarenta plantas de dois grupos, um impactado por atividades humanas e o outro preservado. Nós também avaliamos o investimento da planta em defesas contra herbívoros e os danos foliares causados por herbívoros. Nossos resultados indicam que os distúrbios causam a simplificação da fauna associada e a ausência de uma formiga mutualista anti-herbívoros. Isto leva a quatro vezes mais herbivoria nas plantas da área impactada, a despeito da mesma quantidade encontrada para NEF e formigas visitantes. A grande pressão de herbivoria pode dificultar o reestabelecimento de S. glabra, uma espécie pioneira importante nos campos ferruginosos, dessa forma, afetando a resiliência dessa comunidade ecológica ameaçada