Land animals evolved from ocean ancestors – new study unravels the genetics behind the transition |
The transition from water to land is a question that still intrigues scientists. Those ancient organisms would have needed to adapt to several new challenges to life out of water. So, how did they do it?
In a 2025 study, my colleagues and I tried to understand the genetic basis of adapting to life on land by comparing the genetic material of 150 living animals. We discovered that some adaptations to land are universal, while others are found only in a few lineages.
Animal life started in water over 600 million years ago. Around 500 million years ago animals began their journey from water to land. Known as the Cambrian period, this is one of the biggest evolutionary shifts in Earth’s history, that paved the way for all modern land-based ecosystems.
Although green plants transitioned to land just once around 500 million years ago, animals colonised land at multiple points in time independently. This makes animal life on land a striking example of “convergent evolution” – the process in which different lineages evolve solutions to the same problem. Each of these “jumps” onto land opened up new habitats and had a dramatic effect on the atmosphere and water cycle. This in turn created the modern ecosystems........