Sign of Taxis as a Property of the Genotype

Science  22 Sep 1961:
Vol. 134, Issue 3482, pp. 835-836
DOI: 10.1126/science.134.3482.835


Previous studies have assumed Drosophila to be negatively geotactic and found this to be the case. New methods of observation now yield a spectrum of geotactic behavior both positive and negative. Two-way selection produces races of animals performing in diametrically opposite fashion to the same stimulus conditions.