Bateman's Data: Inconsistent with "Bateman's Principles".

Area of Science:

• Evolutionary Biology
• Behavioral Ecology
• Sexual Selection Theory

Background:

• A.J. Bateman's 1948 study proposed "Bateman's Principles" regarding sex differences in variance in number of mates (V_NM) and reproductive success (V_RS) as a metric for sexual selection.
• Bateman predicted greater V_RS and V_NM in males, with a stronger positive relationship between V_NM and V_RS in males.
• Previous empirical challenges and methodological critiques have questioned the validity of Bateman's original conclusions.

Purpose of the Study:

• To re-evaluate Bateman's predictions using his archived laboratory data.
• To address methodological limitations identified in Bateman's original study and subsequent replications.
• To test for sex differences in V_NM, V_RS, and the relationship between them.

Main Methods:

• Analysis of A.J. Bateman's archived, handwritten laboratory notes from 65 unique populations.
• Application of Punnett's tests to assess the validity of offspring phenotypes derived from parental mutations.
• Statistical analysis of unbiased populations to compare V_RS and V_NM between sexes and examine the relationship between V_NM and V_RS.

Main Results:

• Of the 65 populations, 41.5% failed Punnett's tests, indicating undercounting of parents' number of mates (NM) and V_NM due to biased methods.
• In the 34 unbiased populations, no significant sex differences were found in V_RS or V_NM.
• Regressions revealed weak, positive, significant associations between V_NM and V_RS for both females and males, contrary to Bateman's prediction of a stronger male association.

Conclusions:

• Bateman's original data, when analyzed with unbiased methods, are inconsistent with "Bateman's Principles."
• The study found no evidence for sex differences in V_RS or V_NM, challenging a cornerstone of sexual selection theory.
• The relationship between V_NM and V_RS is similar for both sexes, not stronger in males as predicted by Bateman.