# Multiple developmental pathways in organisms with developmentally complex life cycles

## TL;DR

This paper explores how some organisms can follow multiple developmental paths during their life cycle and how these paths are connected to traits like plasticity and adaptation.

## Contribution

The study provides a comprehensive survey of developmentally complex life cycles across eukaryotes, linking them to morphogenesis, gene expression, and evolutionary patterns.

## Key findings

- Developmentally complex life cycles are linked to phenotypic plasticity and ecological adaptation.
- Multiple developmental pathways within a single organism are connected through shared gene expression patterns.
- Case studies reveal diverse developmental strategies across different species.

## Abstract

One aspect under which an organism’s life cycle can be considered complex is when the very same organism can undertake, or obligatorily undertakes, multiple developmental pathways. Examples are organisms with alternation of generations, like most plants, or organisms with reproductive and/or developmental options, like many marine invertebrates. With a broad taxonomic coverage across the eukaryotes, we survey these developmentally complex life cycles, presenting selected case studies to illustrate the relationships between the diverse developmental pathways within the same organism for what concerns morphogenesis and gene expression. We highlight the deep connections between the different types of cycles and show their relationship with phenotypic plasticity, sexual dimorphism and ecological adaptation. The collected materials and organized concepts can provide the basis for future investigations on the disparity of complex life cycles and their evolution across the tree of life.