Hilary Boden on the latest scientific developments this month
The Black Death was one of the most devastating epidemics of human history, and now an international team of scientists led by researchers at the German University of Tubingen and McMaster University have cracked its genetic code, and sequenced its entire genome.
The skeletal remains of victims buried in the “plague pits” of East Smithfield, London were examined, and the most promising specimens selected in order to obtain the dental pulp of five bodies. The scientists were able to extract, purify and enrich specifically for the pathogen’s DNA, thereby decreasing the background DNA consisting of human, fungal and other non-plague DNA.
The results have been published in a paper in the online journal Nature, which details how this is the first time that scientists have been able to draft a reconstructed genome of any ancient pathogen. As a result, researchers are now able to investigate changes in the pathogen’s evolution over time, potentially leading to a better understanding of modern infectious diseases. Poinar, the associate professor and director of the McMaster Ancient DNA Centre says of the breakthrough: “The genomic data show that this bacterial strain, or variant, is the ancestor of all modern plagues we have today worldwide. Every outbreak across the globe today stems from a descendant of the medieval plague. With a better understanding of the evolution of this deadly pathogen, we are entering a new era of research into infectious disease.” The direct descendants of the same bubonic plague still exist today, killing around two thousand people every year.
However, it was found that the Black Death’s modern day bacterial descendents haven’t progressed particularly over 600 years, and fortunately with the progress of society and medicine, the evolution of our own bodies has significantly overtaken the evolution of the deadly bacterium.
Relationship Satisfaction: Credit to the Pill?
A paper[i] published in a Royal Society Journal this October has illustrated the connection between the contraceptive pill, and female satisfaction in relationships. Dr Craig Roberts, a Stirling University researcher set out to investigate whether the use of oral contraception had an influence on women’s choice of men to father their children. The study examined women who were using the contraceptive pill when they meet their partner, and they were found to be less sexually satisfied or attracted to their partners, but more satisfied with other non-sexual aspects of the relationship. Furthermore, those who met their partner on the pill were less likely to separate and had relationships which lasted on average two years longer than those who were not using oral contraception. As Dr Roberts put it, “One effect seems to compensate for the other.”
Earlier research carried out by Dr Roberts indicated that using the pill affects women’s preference of men’s body odour: when women are on the pill, they are more likely to prefer the odour of more genetically similar men. With smell being a part of the subconscious chemistry of attraction, this is significant. “Women tend to find genetically dissimilar men attractive because resulting babies will more likely be healthy,” Not only does the pill affect women’s sense of smell, it also ensures that they don’t experience as great a variation in hormones throughout their menstrual cycle. While at certain times of the month women who are not on the pill tend to be more attracted to the ‘caring’ and ‘nurturing’ father-type, those who are on the pill are more constant in their attraction. So is using the pill screwing up women’s ability to choose a good partner? It is unclear, but worrying when Dr Roberts adds, “Choosing a non-hormonal barrier method of contraception for a few months before getting married might be one way for a woman to check or reassure herself that she’s still attracted to her partner.” –a slightly discouraging thought.
Software being field tested at the Santa Cruz police department harks back to the fictitious pre-crime system employed in the 2002 film “Minority Report”. Mathematician George Mohler, with his colleagues at Santa Clara University in California, observed that some crimes follow predictable patterns, triggering other crimes in nearby areas, like shocks after an earthquake. They designed software to utilise equations used to predict such aftershocks to process given data about the dates, times and location of previous reported crimes, in order to predict likely locations and times for future wrongdoings.
So far the programme has predicted the correct location and time of on average 25% of real burglaries that occurred on any day in Los Angeles, using only the data collected from burglaries from the day previous. Thus, police can target their patrols on these areas, with the intent to put off any criminals from breaking the law, or at least to be readily at hand to help victims and crack down on perpetrators.
Image credit – Thomas Bartholini
[i] Relationship satisfaction and outcome in women who meet their partner while using oral contraception: S. Craig Roberts1*, Kateřina Klapilová2, Anthony C. Little1, Robert P. Burriss1, Benedict C. Jones3, Lisa M. DeBruine3, Marion Petrie4, Jan Havlíček2, Proceedings of the Royal Society B