Invasive animals are a huge problem all around the globe. They are competing for resources with local species, pushing them to the boarder of extinction. Predicting such invasions is huge ecological and socio-economical interest. However, it is also a very difficult task, because of the large spatial and temporal scales involved.
Now scientists at Eawag and University of Zurich are using computer simulations and small artificial laboratory worlds in order to study how rapid evolution makes invaders spread even faster.
Invasive species of animals are spreading because of human impact. Worldwide mobility and aggregation of markets transports species from one ecosystem to another, sometimes putting species in entirely new continents. Quite often, such invaders spread at very rapid rates. Resident species spread as well because of various reasons, including changing climate. Predicting such dynamics is a really important task for scientists both in ecological and socio-economical regards.
Critically endangered species are important to preserve – sometimes just because of ecological reasons and sometimes they are needed for wellbeing of humans as well. It is also important to predict how these invasive animals will spread, how it can be controlled and, in some cases, prevented. However, most of the current models for such predictions do not work as accurately as situation demands. These models usually predict only slower invasions than one can observe in nature anyway. However, now scientists think that they found a process missing from all considerations – rapid evolution.
Scientists now agree that evolution may be very rapid and occur in very few generations, unlike previously existing notion said. Researchers tried to model these processes in the laboratory. Using advanced computer simulations and small artificial worlds, scientists can observe in real time the course of rapid evolution during species invasions and range expansions. This helped to explain why previous models underestimated speeds of expansion of populations of invasive species. Now the researchers could show experimentally that rapid evolution makes invading species spread even faster. Dr. Emanuel Fronhofer, one of co-authors of the study said that impact of rapid evolution now is obvious. He stated – “the longer we continued our experiments the faster the ciliates were swimming compared to previous generations”.
Similar process was observed with cane toads in Australia. This poisonous species were brought from America and are spreading faster and faster over the whole continent. During this invasion, toads developed stronger legs and now can move faster and cover longer distances. This supports argument about rapid evolution that is happening during cases of invasion of non-native species.
Having in mind that new method includes a process of rapid evolution that was missing in previous models, it should provide scientists with more accurate results. It should also help to better understanding of how these species are spreading and what impact it has on local ecosystem. However, we will have to wait and see whether this will help to control these processes and how methods of prediction can be improved further.