Extreme range in adult body size reveals hidden trade-offs among sexually selected traits

Sexually selected weapons used to monopolize mating opportunities are predicted to trade-off with traits used in competition for fertilization. Yet, the limited size-range typically found among adults of a species often precludes clear comparisons between population-level and individual-level relative trait investment. The jousting weevil, Brentus anchorago (Coleoptera: Brentidae), varies more than 26-fold in body mass, which is among the most extreme adult body size ranges of any solitary terrestrial species. We reveal a trade-off at a population-level: hypermetric scaling in male weapons (slope =1.59) and a closely-mirrored reversal in allocation to post-copulatory traits (slope =0.54). Yet, at the individual-level we find the opposite pattern; males that invest relatively more in weapons for their size class also invest more in post-copulatory traits. In support of our findings from jousting weevils, across 36 dung beetle species we find the relative effect of population-level scalin..., Datasets were collected:
1) from published literature
2) morphological measurements of external morphology from natural populations
3) morphological measurements of internal morphology from natural populations, , # Data from: Extreme range in adult body size reveals hidden trade-offs among sexually selected traits

[https://doi.org/10.5061/dryad.2rbnzs7wr](https://doi.org/10.5061/dryad.2rbnzs7wr)

## Description of the data and file structure

**README\_ Jousting weevil data**

**1. Bren_genitalia_morph.csv**

Measurements in mm of dissected and slide mounted genitalia. Insects were collected from a single population of *Brentus anchorago. *We dissected the testes and sclerotized regions of male genitalia by first removing the abdomen from the body. We then carefully extracted the bilobed testes and placed them on a slide in saline solution to photograph them using a camera (AmScope 10MP MD200-CK) connected directly to the microscope. We measured the surface area of each pair of distinct lobes from each testes in photoshop (Adobe Photoshop CC, 14.2.1 x 64). We used the average of measurements from each pair of testes from a single individual for our analyses. To measure sclerotized parts of the ...

性选择武器（sexually selected weapons）被预测会与用于受精竞争的性状存在权衡关系。然而，多数物种种群内成虫的体型范围通常较为有限，这往往阻碍了种群水平与个体水平上相对性状投入的清晰比较。格斗象鼻虫（Brentus anchorago，鞘翅目Coleoptera：象甲科Brentidae）的体重变异幅度超过26倍，是所有独居陆生物种中成体体型范围最极端的类群之一。我们在种群水平上揭示了一类权衡：雄性武器呈现超等生长（hypermetric scaling，斜率=1.59），而在交配后性状（post-copulatory traits）的资源分配上则呈现近乎镜像式的反向模式（斜率=0.54）。但在个体水平上，我们却观测到相反的规律：相较于其所在体型等级的同类，在武器上投入相对更多的雄性，在交配后性状上的投入也同样更高。为验证我们在格斗象鼻虫中的研究发现，我们对36种蜣螂开展了分析，发现种群水平尺度效应的相对影响……
数据集采集自以下途径：
1) 已发表文献
2) 自然种群外部形态的形态学测量
3) 自然种群内部形态的形态学测量

# 数据来自：成虫体型的极端范围揭示性选择性状间隐藏的权衡
[https://doi.org/10.5061/dryad.2rbnzs7wr](https://doi.org/10.5061/dryad.2rbnzs7wr)

## 数据与文件结构说明
**README_格斗象鼻虫数据**
**1. Bren_genitalia_morph.csv**
该文件包含经解剖并封片的生殖器的毫米级测量数据。实验昆虫采自单个格斗象鼻虫（Brentus anchorago）种群。我们首先将腹部从虫体分离，随后解剖雄性生殖器的睾丸及骨化区域。接着小心提取双叶状睾丸，置于载玻片的生理盐水溶液中，使用直接连接显微镜的相机（AmScope 10MP MD200-CK）进行拍摄。我们使用Adobe Photoshop CC 14.2.1 x64软件，从照片中测量每个睾丸的两个独立叶的表面积。本分析采用单个个体的双侧睾丸测量值的平均值。为测量骨化结构的……