Microbiology of the phyllosphere: a playground for testing ecological concepts

Many concepts and theories in ecology are highly debated, because it is often difficult to design decisive tests with sufficient replicates. Examples include biodiversity theories, succession concepts, invasion theories, coexistence theories, and concepts of life history strategies. Microbiological tests of ecological concepts are rapidly accumulating, but have yet to tap into their full potential to complement traditional macroecological theories. Taking the example of microbial communities on leaf surfaces (i.e. the phyllosphere), we show that most explorations of ecological concepts in this field of microbiology focus on autecology and population ecology, while community ecology remains understudied. Notable exceptions are first tests of the island biogeography theory and of biodiversity theories. Here, the phyllosphere provides the unique opportunity to set up replicated experiments, potentially moving fields such as biogeography, macroecology, and landscape ecology beyond theoretical and observational evidence. Future approaches should take advantage of the great range of spatial scales offered by the leaf surface by iteratively linking laboratory experiments with spatial simulation models

The functional brain networks that underlie Early Stone Age tool manufacture

After 800,000 years of making simple Oldowan tools, early humans began manufacturing Acheulian handaxes around 1.75 million years ago. This advance is hypothesized to reflect an evolutionary change in hominin cognition and language abilities. We used a neuroarchaeology approach to investigate this hypothesis, recording brain activity using functional near-infrared spectroscopy as modern human participants learned to make Oldowan and Acheulian stone tools in either a verbal or nonverbal training context. Here we show that Acheulian tool production requires the integration of visual, auditory and sensorimotor information in the middle and superior temporal cortex, the guidance of visual working memory representations in the ventral precentral gyrus, and higher-order action planning via the supplementary motor area, activating a brain network that is also involved in modern piano playing. The right analogue to Broca’s area—which has linked tool manufacture and language in prior work1,2—was only engaged during verbal training. Acheulian toolmaking, therefore, may have more evolutionary ties to playing Mozart than quoting Shakespeare

The distribution of ciliates on Ecology Glacier (King George Island, Antarctica): relationships between species assemblages and environmental parameters

Ciliates are important consumers of pico- and nano-sized producers, are nutrient regenerators, and are an important food source for metazoans. To date, ecological research on ciliates has focused on marine ecosystems rather than on glacier habitats. This paper presents the first major study on ciliates from the Ecology Glacier (South Shetland Islands, Antarctica). The objective of the study was to investigate the structure and spatial distribution of ciliate communities and to identify the environmental factors determining the structure of the assemblages. Microbial communities were collected from three habitats: surface snow, cryoconite holes, and glacier streams. Sampling was carried out every 3–4 days from January 17 to February 24, 2012. A total of 18 ciliate taxa were identified. The species richness, abundance, and biomass of protozoa differed significantly between the stations studied with the lowest numbers in streams on the glacier surface and the highest numbers in cryoconite holes. The RDA performed to specify the direct relationships between the abundance of ciliate taxa and environmental variables showed obvious differences between studied habitats. The analysis showed that all variables together explained 62.4 % of total variance. However, variables thatsignificantly explained the variance in ciliate communities in cryoconite holes, snow, and surface streams were temperature, conductivity, and total nitrogen. Further research is required to explain the impact of biotic factors influencing the presence of ciliates, including the abundance of bacteria, microalgae, and small Metazoa