Microbes as manipulators of egg size and developmental evolution

Marine invertebrates mainly reproduce by energy-poor eggs that develop into feeding larvae or energy-rich eggs that develop into non-feeding larvae. Evolutionary transitions between these developmental modes have been studied in detail, yet the evolutionary factor(s) responsible for these switches remains elusive. Here, we use theoretical models to support the premise that microbes with the capacity to manipulate host reproduction may be one possible factor. Our model predicts that microbial manipulators could create a sperm-limited environment that selects for larger eggs by shifting the host’s sex ratio toward female dominance and, as a result, drive an evolutionary transition in the developmental mode for marine invertebrates. The loss of a microbial manipulator could then recover the ancestral egg size and developmental mode. We also suggest more than a dozen genera of marine invertebrates from throughout the world’s oceans that fit the framework of a microbe-induced evolutionary tr..., , , Description of code and data files affiliated with Kustra and Carrier 2025 \"*Microbes as manipulators of egg size and developmental evolution*.\"

For questions, contact: Matthew Kustra: [[e-mail]](mailto:[e-mail])

To properly run the **analysis** code, first unzip both **\"Code.zip\"** and **\"Data.zip.\"** Then, make sure the Code and Data files are in the directories described below. This is most easily accomplished by moving all code files in the ***Analysis*** directory of the unzipped **\"Code.zip\"** to the directory above the unzipped **\"Data.zip.\"**

Below is a description of all the code and data files broken down by the directories in which code and data files should be organized in.

**Running Sims** and **Analysis** files uploaded to **Zenodo**.

***Running_Sims***: Folder that contains all the files needed to run simulations. Only occurs in **\"Code.zip\"** and does not require any data.

* **\"QGPop_Simulation.jl\"**: Julia script that was used for o...,