Related Experiment Video
Updated: Aug 18, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
Analysis of the human sex ratio by using overdispersion models
Abstract:
Data from nineteenth-century Germany are reanalyzed to determine how the probability for having a child of each sex changes with family size. The data, collected by A. Geissler, concern some 1 million birth registrations and 3.7 million births occurring in Saxony between 1876 and 1885. Three models are fitted to the data. "The multiplicative and beta-binomial models provide similar fits, substantially better than that of the double-binomial model. All models show that both the probability that the child is a boy and the dispersion are greater in larger families. There is also some indication that a point probability mass is needed for families containing children uniquely of one sex."
More Related Videos
Related Concept Videos
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Test for Homogeneity
Testing a Claim about Population Proportion
There are two methods of testing a claim about a population proportion: (1) Using the sample proportion from the data where a binomial distribution is approximated to the normal distribution and (2) Using the binomial probabilities calculated from the data.
The first method uses normal distribution as an approximation to the binomial distribution. The requirements are as follows: sample size is large...
Analysis of Population Pharmacokinetic Data
Mechanistic Models: Compartment Models in Individual and Population Analysis
Modeling with Differential Equations

