Fraxinus involves matching and rearranging patterns of coloured leaf shapes which represent "nucleotides" - the letters that make up a genome sequence. People are better at this than computers alone, because the human eye can recognise patterns that computers miss.
The Facebook game is part of a rapid response to ash dieback funded by the Biotechnology and Biological Sciences Research Council, which includes understanding more about the disease, how it attacks ash trees, finding natural resistance and predicting and mitigating disease progression.
Visit the BBSRC news page>http://www.bbsrc.ac.uk/news/fundamental-bioscience/2013/130813-pr-gamers-to-join-ash-dieback-fight-back.aspx
Go direct to the game> https://apps.facebook.com/fraxinusgame/