On Jan 16, 2012, at 10:55 AM, Ken Steele wrote: > Jeff: > > That is a very cool maze. It looks like a rotated Galton quincunx. How was > it supposed to work?
"Was" isn't the correct word: these mazes still are used, although I haven't kept up with the recent research. The last article I read was published in Nature Genetics about 10 years ago, in which the divergently selected lines from Hirsch's lab were genetically analyzed using cDNA microarrays. As for your question: a sample of flies are placed in a tube and the tube is attached to the left side of the maze pictured in the image I linked to. The maze consists of 15 sequential T-choice points (for each fly), which leads to a distribution at the end: flies at the top moved against gravity, flies at the bottom moved towards gravity. The maze was based on earlier work on taxes by biologists such as Jacques Loeb. The flies were divergently selected beginning around 1960: in one line, flies moving against gravity were mated with each other; and in the other line, the same was done with flies that moved towards gravity. When I started using the lines in the mid-1980s, the lines had been selected for 1000s of generations and had evolved very different genetic systems (groups of interacting genes) from the founding population. I had a great deal of fun trying to figure out what changes had occurred, as did others after me. Best, Jeff Reference: Toma, D. P., White, K. P., Hirsch, J., Greenspan, R. J. (2002). Identification of genes involved in Drosophila melanogaster geotaxis, a complex behavioral trait. Nature Genetics, 31, 349-353. doi:10.1038/ng893 -- --------------------------------------------------------------------------------- Jeffry Ricker, Ph.D. SCC: Professor of Psychology MCCCD: General Studies Faculty Representative PSY 101 Website: http://sccpsy101.wordpress.com/ --------------------------------------------------------------------------------- Scottsdale Community College 9000 E. Chaparral Road Scottsdale, AZ 85256-2626 Office: SB-123 Phone: (480) 423-6213 Fax: (480) 423-6298 --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=15361 or send a blank email to leave-15361-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
