news Is there anyone out there? Do intelligent extraterrestrial beings exist? Not according to Professor Andrew Watson from the University of East Anglia, who has used a mathematical model to show that the probability of finding intelligent life on other planets is very low. His stochastic model considers the timings involved in the evolution of life on Earth, taking into account the current age of the planet Earth and the steps required for the evolutionary process. Standard solar models predict that the luminosity (brightness) of the sun is increasing and that the resulting temperature increase means that the Earth’s biosphere is nearing the end of its lifespan (it is likely to last for “only” another billion years). “The Earth’s biosphere is now in its old age and this has implications for our understanding of the likelihood of complex life and intelligence arising on any given planet”, says Professor Watson. “At present, Earth is the only example we have of a planet with life. If we learned the planet would be habitable for a set period and that we had evolved early in this period, then even with a sample of one, we’d suspect that evolution from simple to complex and intelligent life was quite likely to occur. By contrast, we now believe that we evolved late in the habitable period, and this suggests that our evolution is rather unlikely. In fact, the timing of events is consistent with it being very rare indeed.” The model used by Professor Watson assumes that the timing of evolution is governed by the necessity to pass a number of critical time steps. He suggests that in the case of humans, the number of time steps is four, representing the emergence of (i) single-celled bacteria (prokaryotes), (ii) complex cells (eukaryotes), (iii) cell differentiation (allowing complex organisms to develop) and (iv) humans. Professor Watson calculated the probability of each of these steps occurring in relation to the lifespan of Earth, and concluded that the evolution of life on Earth was statistically improbable – therefore the chance that the same thing has happened on other habitable planets in the universe is very small. New statistical method to identify dangerous genes There are over 20,000 genes in the human genome, which makes A mathematical model has been used to show that intelligent extraterrestrial life is unlikely to exist Image courtesy of NASA/JPL-Caltech 6 iSquared magazine Summer 2008
The prevailing image of mathematicians is of old, white, men who are obsessive about maths and lack social skills, a stereotype associated with John Nash and Albert Einstein identifying those that cause a specific disease a bit like searching for the proverbial needle in a haystack. However, mathematicians at Michigan Technological University have developed a powerful new tool for pinpointing the genes behind inherited diseases. The research group, led by assistant professor Qiuying Sha, have produced computer software called the Ensemble Learning Approach (ELA) that uses statistical methods to isolate the combinations of genetic variations that can lead to a disease. “With chronic, complex diseases like Parkinson’s, diabetes and ALS [Lou Gehrig’s disease], multiple genes are involved,” says Sha. The ELA makes it much easier to tackle the difficult problem of finding genetic variations that act together to cause illness. By using their software with data from diabetes patients, the team identified 11 genetic variations that are linked to type II diabetes with a high probability. If their findings are correct, they will help to improve scientists’ understanding of the cause of diabetes, which will in turn aid the search for better treatments or even a cure. “Geeky” maths image deters students Research funded by the Economic and Social Research Council (ESRC) has revealed that many people are being deterred from studying or using mathematics by the “geeky” www.isquaredmagazine.co.uk image of mathematicians. Dr Heather Mendick and Marie-Pierre Moreau, both from London Metropolitan University, and Professor Debbie Epstein from Cardiff University carried out surveys, focus groups and individual interviews with students, as well as “Identifying the genes that cause a specific disease is like searching for a needle in a haystack” analysing references to maths in modern culture (including those in TV programmes, films, books and websites). The subjects involved in the project included GCSE students, mathematics undergraduates and also university students (both postgraduate and undergraduate) studying social sciences and humanities. The researchers wanted to find out how popular images of mathematics affect people’s feelings towards the subject, and whether these images have played a role in the decline of interest in maths that has been seen in the last decade. The conclusion of the project was that negative images of maths do contribute to this lack of interest. “Given the narrow, negative clichés associated with maths and mathematicians, it is hardly surprising that relatively few young people want to continue with the subject”, says Dr Mendick. “A substantial majority of both Year 11 and university students saw maths as little more than numbers and mathematicians as old, white, middle-class men.” Mathematicians were seen as “nerdy” or “geeky” by many of the participants, even by those who were themselves studying maths at university. The prevailing image of mathematicians was that they were obsessed with their subject, lacked social skills and led lonely lives, although some of those who continue to study maths regard the idea of obsession with maths as an indication of devotion to the subject and see the “geek” image as having positive value (the latter was particularly true among male students). According to Dr Mendick, this research “raises two important issues: first, we can see how popular culture is deterring many people from enjoying maths and wanting to carry on with it and, second, it raises issues in relation to social justice as these images are mainly of white, middle-class men and so may discourage other groups disproportionately.” News articles by Sarah Shepherd iSquared magazine 7 Left image by Elke Wetzig. Right image by Ferdinand Schmutzer.