This dataset contains data from: Cotton, A.J., Fšldv‡ri, M., Cotton, S. and Pomiankowski, A. 2013. Male eyespan size is associated with meiotic drive in wild stalk-eyed flies (Teleopsis dalmanni). Published in Heredity. The data were collected by Alison Jennifer Cotton, email: alison.cotton.10@ucl.ac.uk Mihaly Fšldv‡ri, email: mfoldvari@gmx.net Samuel Cotton, email: malayjunglesam@gmail.com Andrew Pomiankowski, email: ucbhpom@ucl.ac.uk The data is saved in two .csv files Cotton et al. Wild Males Sex Ratio.csv This file was used for the analysis of a) the relationship of between the offspring sex ratio of males and male eyespan and b) the relationship between the offspring sex ratio of males and 7 X-linked microsatellites (31 of 134 males were genotyped). The columns are labelled: Male ID: denoting fly identity, used for reference. Eyespan: denotes eyespan, defined as the distance between the outermost tips of the eyes (mm). Thorax: denotes thorax length, defined as the distance from the base of the head to the posterior edge of the thorax (mm). Male Offspring: denotes the number of male offspring produced by each male. Female Offspring: denotes the number of female offspring produced by each male. Total Offspring: denotes the total number of offspring produced by each male. MS395: denotes the allele size of microsatellite ms395 for each male. MS395 nominal: denotes the nominal ms395 allele size category (10bp in length) for each male. The same column notation was used for the other microsatellites where MSXX: denotes the allele size of that microsatellite and MSXX nominal: denotes the nominal allele size category (10bp in length). The other microsatellites are MS54, MScrc2, MS244, MS106, MS125 and MS167. Cotton et al. Adult Data.csv This file was used for the analysis of a) the relationship between 8 X-linked microsatellites and key phenotypic traits (eyespan, fecundity, accessory gland size and testis size) and b) the relationship between both population density and different wild populations with microsatellite ms395 allele size. The columns are labelled: Individual ID: denoting fly identity, used for reference. Site: denotes the population that the individual was collected from along the Gombak valley, Malaysia. Sex: denotes the sex of an individual fly where M = Male and F = Female. Population Density: denotes the density of the population where the fly was collected. This was calculated using an average based on three collections taken at the same site over three years. The density was estimated as the number of flies collected per metre of site sampled. Eyespan: denotes eyespan, defined as above. Thorax: denotes thorax length, defined as above. Fecundity: denotes female fecundity defined as the number of mature eggs in the ovaries upon dissection. Accessory Glands: denotes the average length of two dissected and uncoiled male accessory glands (mm). Testes: denotes the average length of two dissected and uncoiled male testes (mm). MS395-1: denotes the first allele size of microsatellite ms395. MS395-2: denotes the second allele size of microsatellite ms395. MS395>Mean: denotes whether the individual has allele sizes greater than the population mean for that microsatellite, where 0 = neither of the alleles are greater than the population mean, 0.5 = one of the two allele sizes are greater than the population mean (possible in females only) or 1 = both alleles are greater than the population mean. The same column notation was used for the other microsatellites where MSXX-1: denotes the first allele, MSXX-2: denotes the second allele and MSXX>Mean: denotes whether the individual has 0,1 or 2 alleles greater than the population mean. The other microsatellites are MS54, MScrc2, MS244, MS106, MS125, MS167 and MS71.