Stalk-eyed flies carrying a driving X chromosome compensate by increasing fight intensity

Exaggerated ornaments provide opportunities for understanding how selection can operate at different levels to shape the evolution of a trait. While these features aid their bearer in attracting mates or fending off competitors, they can also be costly and influenced by the environment and genetic variation. Eyestalks of the stalk-eyed fly, Teleopsis dalmanni, are of interest because eyestalk length is the target of both intra-and intersexual selection and is also reduced by loci on a highly-diverged sex ratio X chromosome (XSR), a meiotic driver accounting for up to 30% of wild X chromosomes. Male stalk-eyed flies fight to control access to females and over food using a combination of low intensity displays and high intensity physical fights. We staged, filmed and scored contests among eyespan-matched male pairs to evaluate whether X chromosome type impacts the behavior and outcome of aggressive interactions. While our results broadly match expectations from previous studies, we find t..., Following previous studies of fighting in stalk-eyed flies (Panhuis and Wilkinson 1999; Egge et al. 2011; Bubak et al. 2014), we quantified male aggressive behavior in two sets of trials conducted either at SUNY Geneseo (outbred pair trials) or the University of Maryland, College Park (standardized opponent trials). We conducted trials with outbred and inbred flies as opponents to confirm that the results were robust to the opponents’ genetic background. Sexually mature males at least four weeks post-eclosion were anesthetized using carbon dioxide, eyespan and body length were measured from video-captured images to the nearest 0.01 mm using ImageJ. All trials were conducted in transparent plastic arenas (10 x 3.5 x 6 cm) lined with moist blotting paper and initially divided into three sections by opaque plastic barriers.  Each male was placed into an outer compartment of the arena and fasted 20-24 h.  At the beginning of the trial, a piece of agar gel made with corn juice was ..., , # Dataset: Stalk-eyed flies carrying a driving X chromosome compensate by increasing fight intensity

[https://doi.org/10.5061/dryad.79cnp5j51](https://doi.org/10.5061/dryad.79cnp5j51)

## Description of the data and file structure

We staged, filmed and scored contests among eyespan-matched pairs of stalk-eyed fly males to evaluate whether X chromosome type impacts the behavior and outcome of aggressive interactions.  Males were genotyped for the presence of a meiotic drive X chromosome after scoring. 

### Files and variables

#### File: Editorial\_1.XLSX

**Description of the data table columns**

| **Variable** | **Description** |
| :-------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Trial type | Standa...,