Evolutionary power of nature: How aphids influence water fleas!

Evolutionary power of nature: How aphids influence water fleas!

Researchers at Johannes Gutenberg University Mainz (JGU) have shown in a groundbreaking study that indirect ecological effects can significantly influence the evolution of species. These findings, which were obtained in collaboration with the Swiss Federal Institute of Aquatic Science and Technology (Eawag) and the University of Basel, represent a significant advance in evolutionary biology. The research results were published in the renowned journal PNAS. Prof. Dr. Shuqing Xu, one of the lead authors, explained how aphids influence the evolution of water fleas even though they live in different habitats.

In experimental ponds with a volume of 15,000 liters, it was observed that the aphids feeding on duckweed reduced the reproduction of these aquatic plants. This led to increased light transmission, which in turn promoted the growth of algae, which fed the water fleas. The researchers analyzed water samples every two weeks and documented the changes in the ponds. In the second year it was found that the water flea population in the ponds with aphids had increased, which was due to the richer food supply due to the increased algae growth.

Coevolution and indirect effects

The study makes it clear that even species that do not interact directly can influence each other's evolution. Genomic analyzes showed significant differences between water fleas from ponds with aphids and those from control ponds. The latter were able to adapt more easily to the conditions of the ponds with aphids, while the water flea populations living in “aphid ponds” experienced challenges in adaptation. However, these evolutionary adaptations came at a cost, as the water fleas could now only survive in more nutrient-rich ponds.

This research complements existing knowledge of coevolution, which often focuses on closely interacting pairs of species. The international research team, including the University of Zurich, has recognized that coevolution can also take place in complex networks with many species. In these species-rich communities, not only direct interactions are crucial, but also indirect effects, which often play a more important role

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The importance of global cooperation

The JGU findings underline the need for international collaboration in biological research. Evolutionary theory needs to be expanded to include an understanding of these complex interactions in order to capture the dynamics in a wide variety of ecosystems.

An example of such dynamic interactions occurs in predator-prey relationships, which represent a classic model of coevolution. Membership in ecosystems influences the evolutionary characteristics of predators and prey. For example, predators such as foxes or birds of prey develop skills to capture their prey more efficiently, while prey animals such as rabbits or insects develop strategies to increase their survival rate.

This shows that coevolution is not only limited to directly interacting species, but also to complex networks, where rapid environmental changes can potentially trigger cascading evolutionary changes. Feedback in these complex systems can lead to the stability or instability of a community.

In the future, it will be crucial to take these findings into account in research to better understand and manage the impacts of climate change and other human impacts on biodiversity. The increasing interest in these topics could mean that we are looking forward to a new era in biology in which the complexity of interactions is at the forefront, not just the isolated behavior of individual species.

For more information see the studies by JGU, University of Zurich and Studyflix.