A pregnant fossil fish at the Natural History Museum in London has shed light on the possible origin of sex, according to a study published today in the journal Nature by an international team including Museum scientists.

The fossil is an adult placoderm, an extinct group of armored fish, and it contains a 5cm-long embryo.  It is dated to the Upper Devonian period 350 million years ago and was found in the Gogo formation of western Australia.  The fish species is Incisoscutum ritchiei and this specimen is one of the earliest examples of a pregnant vertebrate and shows that internal fertilisation, or sex, started far sooner than previously thought.

A 380-million-year-old fossil fish that shows an unborn embryo and umbilical cord has been discovered, write scientists from the Natural History Museum in Nature.  The extremely rare specimen shows incredible detail. The umbilical cord is attached to an area of small bones, corresponding to the embryo. This means the fish would have given birth to live young, known as viviparity and is the oldest record of this kind known.

'The find is important because it provides concrete evidence for vivparity,' says Zerina Johanson, fossil fish curator at the Natural History Museum.


Fossil specimen found in Australia showing the umbilical cord and embryo parts. © Museum Victoria

Starting with the tiny fruit fly, and then moving into mouse and human patients, researchers at VIB connected to the Center for Human Genetics (K.U. Leuven) say they have showed that the same gene suppresses cancer in all three. Reciprocally, switching off the gene leads to cancer. The scientists think there is a good chance that the gene can be switched on again with a drug.

With sexual activity among adolescents in the United States resulting in over 750,000 teenage pregnancies each year and reports of up to 25 percent of all female adolescents in the US having sexually transmitted infections, researchers and public health officials are looking for those factors that might increase sexual activity in teens. In an article published in the April 2009 issue of the American Journal of Preventive Medicine, researchers say that teenagers who preferred popular songs with degrading sexual references were more likely to engage in intercourse or in pre-coital activities. 

A team of scientists has used game theory to explain the bizarre behavior of a group of ravens.   Juvenile birds from a roost in North Wales have been observed adopting the unusual strategy of foraging for food in 'gangs.'   New research published in PLoS One explains how this curious behavior can be predicted by adapting models more commonly used by economists to analyse financial trends.

This is the first time game theory has been used to successfully predict novel animal behavior in the real world. The researchers believe this analysis could also shed light on the variation in feeding strategies in different populations in other species.

Women undertaking a ten week program of 75 minute Restorative Yoga (RY) classes gained positive differences in aspects of mental health such as depression, positive emotions, and spirituality (feeling calm/peaceful) compared to the control group. The study, published today in a special issue of Psycho-Oncology focusing on physical activity, shows the women had a 50% reduction in depression and a 12% increase in feelings of peace and meaning after the yoga sessions.