Variety of animals evolved similar genetics solutions to survive on land, study finds

Animals from completely different branches of the tree of life such as insects, worms and vertebrates independently evolved similar genetic solutions to survive on land, according to a new study from researchers at the University of Bristol and University of Barcelona.

The research, published in Nature today [12 November] suggests that some adaptations are so essential that environmental challenges make evolution predictable.

The researchers decoded the genetic basis of one of evolution’s more extraordinary innovations – the transition from water to land.

Because the transition from water to land happened multiple times during the evolution of the animal kingdom, it presented scientists with a unique opportunity for gaining insight into evolutionary adaptations. By comparing 154 genomes across 21 animal lineages, the team was able to identify the genetic basis for each of these transitions from water to land, analysing what they have in common and what makes them unique.

Lead author Jialin Wei from the School of Biological Sciences said: “We show that despite evolving separately, different groups living on land — from insects to vertebrates — repeatedly gained and lost similar genes to survive outside water.

“Our findings reveal that key biological functions like water regulation, metabolism, reproduction, and sensory perception evolved independently but repeatedly across diverse unrelated lineages, explaining which adaptations were required to conquer land.”  

Dr Jordi Paps Monserrat, Associate Professor in Genomics and Evolution in the School of Biological Sciences, added: “Interestingly, animals that still rely partly on aquatic environments (mostly tiny invertebrates) tend to share more adaptations, while fully terrestrial lineages (arthropods or us) show more divergent strategies. Each lineage also carries its own unique innovations, reflecting unique evolutionary paths shaped by ecology, physiology, and chance.”

Dr Marta Álvarez-Presas, project co-lead from the University of Barcelona, explained: “The study identifies three major waves of terrestrialisation over the past 487 million years, lead first by the successful arthropods and ending with land snails like the ones that live in our gardens.  By tracing these transitions across millions of years, the study offers a rare glimpse into what might happen if we could ‘replay the tape of life’.

“Some genetic adaptations appear strikingly predictable, emerging again and again in response to life on land, while others are contingent, shaped by the quirks of each. This research offers fresh insight into how genes shape ecosystems and advances of our understanding of adaptation.”