A trend test for the analysis of multiple paternity

  • Markus NeuhäuserEmail author
  • Bernd Leisler
  • Ludwig A. Hothorn
Editor’s Invited Article


The aquatic warbler, Acrocephalus paludicola, is one of a few species in which nestlings from a single nest can be sired by up to four different fathers. Data from a DNA fingerprinting study suggest that there is a trend: the larger the number of fathers in a brood the larger is the number of nestlings. However, the number of young within a single nest cannot be smaller than the number of fathers. This restriction causes an inherent trend and, consequently, can lead to a false-positive trend test result. For this nonstandard situation, we propose a trend test that differentiates between the inherent trend and a “real” trend, that is, a larger brood size through multiple paternity. Using DNA fingerprinting data, we performed a randomization test using the proposed new trend test statistic and obtained a significant result (P=0.047). This indicates that a larger number of fathers per brood is associated with a larger brood size. In addition, we consider an umbrella alternative, that is, a downturn in effect may occur after the optimal number of fathers per brood is exceeded. An appropriate test for this alternative also leads to a significance (P=0.011).

Key Words

DNA fingerprinting Jonckheere-Terpstra test Nonstandard situation Randomization test Umbrella alternative 


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Copyright information

© International Biometric Society 2003

Authors and Affiliations

  • Markus Neuhäuser
    • 1
    Email author
  • Bernd Leisler
    • 2
  • Ludwig A. Hothorn
    • 3
  1. 1.Department of Mathematics and StatisticsUniversity of OtagoDunedinNew Zealand
  2. 2.Max Planck Research Center for OrnithologyVogelwarte RadolfzellRadolfzellGermany
  3. 3.Bioinformatic UnitUniversity of HannoverHannoverGermany

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