This paper describes the development of a bee swarm algorithm for optimising the distribution of impact detection sensors on a composite plate. The algorithm was initially developed and tested on a travelling salesman problem, it was then adapted to solve the sensor placement problem using an artificial neural network to assess the fitness of sensor distributions. It performed well, managing to quickly find optimum distributions within a constrained set of neural network parameters. The algorithm was modified further, to optimise the neural network parameters alongside the sensor distributions and the range that the network parameters could take was substantially increased. This led to significant increases in accuracy. The algorithm showed itself to be a very effective tool in the sensor optimisation problem as well as demonstrating the benefits of thoroughly optimising the neural network parameters.

Genetic exchanges between closely related groups of organisms with different adaptations have well-documented beneficial and detrimental consequences. In plants, pollen-mediated exchanges affect the sorting of alleles across physical landscapes and influence rates of hybridization. How these dynamics affect the emergence and spread of novel phenotypes remains only partially understood. Here, we use phylogenomics and population genomics to retrace the origin and spread of two geographically overlapping ecotypes of the African grass Alloteropsis angusta . In addition to an ecotype inhabiting wetlands, we report the existence of a previously undescribed ecotype inhabiting Miombo woodlands and grasslands. The two ecotypes are consistently associated with different nuclear groups, which represent an advanced stage of divergence with secondary low-level gene flow. However, the seed-transported chloroplast genomes are consistently shared by distinct ecotypes inhabiting the same region. These patterns suggest that the nuclear genome of one ecotype can enter the seeds of the other via occasional pollen movements with sorting of nuclear groups in subsequent generations. The contrasting ecotypes of A. angusta can thus use each other as a gateway to new locations across a large part of Africa, showing that hybridization can facilitate the geographical dispersal of distinct ecotypes of the same grass species.