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Evolution in changing environments. heavy metal adaptation in experimental yeast populations as a case study

Directional environmental change in the form of global climate change and human-induced pollution is one of the most pressing problems facing society today. It is thus very important that we learn to better understand if and how organisms can adapt to such change. I investigated whether organisms adapt in the same way to gradual vs. abrupt changes in their environment by evolving populations of baker’s yeast in the laboratory for hundreds of generations in the presence of different heavy metals. I found that populations exposed to gradual change adapt more slowly, but end up being just as adapted as populations exposed to sudden change. However, in many cases different mutations were responsible for adaptation to gradual and abrupt change, and this can have important consequences for further evolution. So, it is important that we learn to take into account not only the magnitude of environmental change, but also its rate.