The Looking Glass

MR G.W. ROWE, HEAD OF BIOLOGY What is it? In simple terms the R0 is a disease’s basic reproductive ratio - the number of cases at time zero measured compared to the number of cases at a future date. If there were 100 cases of disease X last week and 500 this week this would give a ratio of 1:5 and the R0 would be given as 5. Therefore, an R0 of 1.0 means the epidemic is infecting the same number of people over time and is not accelerating. An R0 of above 1.0 will lead to an exponential increase in the numbers infected and an R0 below 1.0 will lead to a decline in the numbers infected by the disease. There are many complex interacting factors which determine R0 for example, method of transmission (airborne droplet = generally lead to higher R0 values than sexual transmission), period of time where those infected are able to transmit the disease and success in isolating those infected from the general population. But, in a nutshell, the first paragraph describes what most people need to ...

JAMIE BARRETT Thousands of metres beneath the waves of the Norwegian Sea, on a throne of iron and sulphur, a strange family of microbes thrives among 300°C waters. Their very existence may force us to rewrite the tree of life. Since the discovery of archaea in the 1970s, the predominant picture of life was split into three distinct domains: bacteria, archaea (a type of single-celled organism without a nucleus), and eukaryotes. James Lake at the University of California noticed that eocytes, a type of archaea discovered in the 1980s, had cellular features that were similar to those of eukaryotes. He argued that these similarities suggested a more recent evolutionary connection between archaea and eukaryotes. He proposed that eukaryotes are a branch within archaea, rather than a separate domain. Lake’s idea - known as the eocyte hypothesis - was largely ignored. However, a decade ago, Martin Embley and his team at Newcastle University attempted to see how bacteria, archaea, and eukaryote...

RAFI BRISTER In the search for both extraterrestrial life and possible habitable extraterrestrial bodies, there are many contributing factors but one of the most important ones is the chemical composition of the body. All life on Earth needs water as a solvent for biological reactions to take place and about 95% of all living matter is built on carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur with all other elements being found in trace amounts and a total of 29 playing an active role in biological reactions. However, while modern life has evolved to live with the atmospheric concentrations of gases (primarily oxygen and nitrogen) as they are, this means that they could not or would struggle to survive on a planet where this balance was not present (including for example the Earth during the Cretaceous Period). This means that in the search for extraterrestrial life, planets which have the required concentrations of these elements detectable are higher priority candidates. Ho...