An ancient Daphnia pulicaria individual resurrected from South Center Lake (Minnesota, USA). This individual was hatched from an egg recovered from sediments that date back to circa 1418-1301 A. D. OU scientists have recently studied other members of this species to understand rapid evolution to human-caused pollution in lake ecosystems. Credit: Dagmar Frisch
Human actions are changing the environment at an unprecedented rate. Plant and animal populations must try to keep up with these human-accelerated changes, often by trying to rapidly evolve tolerance to changing conditions.
University of Oklahoma researchers Lawrence Weider, professor of biology, and Matthew Wersebe, a biology doctoral candidate, have demonstrated rapid evolution in action by sequencing the genomes of a population of Daphnia pulicaria, an aquatic crustacean, from a polluted lake.
The research, which was conducted as part of Wersebe’s doctoral dissertation, was recently published in the Proceedings of the National Academy of Sciences. Wersebe and Weider revived decades-old Daphnia resting eggs from lake sediments, a method known as resurrection ecology, which has been refined in Weider’s lab over the past several decades. They then sequenced the entire genomes of 54 different Daphnia individuals from different points-in-time, allowing them to study the genetics and evolution of the population.
The Daphnia were collected from Tanners Lake, located in Oakdale, Minnesota. Tanners Lake has suffered significant salt pollution, stemming from the widespread use of road deicing salts in its watershed.
Daphnia, also known as water fleas, play critical roles in environmental monitoring. For example, they have served as important test organisms in laboratories around the world for over a century because of…
2023-02-02 17:01:30 Decades-old crustaceans coaxed from lake mud give up genetic secrets revealing evolution in action
Link from phys.org Scientists have recently revealed details of a remarkable feat of extracting large amounts of genetic data from decades-old crustaceans pulled from a lake sediment core near Berlin, Germany. This groundbreaking discovery has allowed scientists to observe evolution in action, offering insights into how species adapt over time.
In an article published this month in the journal Molecular Biology and Evolution, a team of researchers describe their findings from a sediment core taken from a lake nearly 75 miles north of Berlin. The core revealed a wealth of crustacean remains at various depths representing tens of thousands of years of lake sediment deposition. The remains included thousands of individuals from three different species of Daphnia, a group of tiny freshwater crustaceans that are widely used in scientific research.
The researchers used the latest technology in ancient DNA analysis to extract mitochondrial genomes from these crustacean remains, revealing adaptations of multiple species that occurred over the 10,000-year lifespan of the lake. By comparing genetic data from different periods, the researchers were able to observe how the species adapted to changing environmental conditions in the lake, as well as to competition with other species.
The results of this study provide evidence that species can adapt to changing environments in as little as a few hundred to a few thousand years, much faster than other forms of evolution such as selection by climate or competition from other species. The findings suggest that species have an almost immediate response to changes in their environment, and can adjust rapidly to survive over long periods of time.
In addition to its implications for biological evolution, this study highlights the significance of ancient DNA analysis in uncovering long-term evolutionary histories. It is a powerful tool that can give us further insight into the history and future of species that inhabit our planet. This discovery is likely to be remembered as one of the most significant advances in evolutionary research in recent years.
