Land animals evolved from ocean ancestors—new study unravels the genetics behind the transition
Why it matters: Understanding ancient genetic adaptations offers insights into how life overcomes extreme environmental challenges, informing future ecological and biological research.
- Sadie Harley and Robert Egan, scientific and associate editors, respectively, highlight the enduring scientific intrigue surrounding the water-to-land transition and the challenges ancient organisms faced.
- The 2025 study, led by Harley and colleagues, analyzed 150 animal genomes to identify genetic changes associated with adapting to land, revealing both shared and unique adaptations across lineages.
- Convergent evolution is exemplified by animals colonizing land multiple times independently, unlike plants, with each transition profoundly impacting Earth's atmosphere and water cycle.
- Genetic turnover, involving significant gene gains and losses, was found to accompany most land transitions, with genes related to dehydration and stress response (temperature, UV, toxins) repeatedly gained.
- Genes linked to regeneration, diet, and biological clocks were frequently lost or diminished during the transition, suggesting a shift in functional priorities for terrestrial life.
- Life's move to land dramatically reshaped the planet by removing CO₂, increasing oxygen, and weathering rocks, thereby influencing global ecosystems and mineral cycles.
A new 2025 study, detailed in Nature, unravels the genetic underpinnings of how animals transitioned from ocean to land, a pivotal evolutionary shift that occurred multiple times independently. By comparing 150 animal genomes, researchers identified universal and lineage-specific genetic adaptations, particularly highlighting genes related to dehydration and stress response as key to terrestrial survival.
