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Evolution on an Ecological Scale

Drought on the Galapagos Islands wiped out 85% of finch populations and shifted their evolution in a single generation. Credit: schame87/Adobe

Drought on the Galapagos Islands wiped out 85% of finch populations and shifted their evolution in a single generation. Credit: schame87/Adobe

By Martino E. Malerba

Darwin’s theory of natural selection may be simple and intuitive, but some of its key assumptions are now being called into question.

The full text of this article can be purchased from Informit.

At the end of the 19th century, Charles Darwin revolutionised our way of thinking about nature: in every species, the individuals with the highest “fitness” for their specific environment are more likely to survive and pass on their successful genes to the next generation. This mechanism of “natural selection” implies that all species continuously evolve, generation after generation, by accumulating beneficial mutations that can gradually improve the fitness of the species. Darwin’s theory of evolution is the most popular concept of how life reached its current state.

Following Darwin’s natural selection theory on how species evolve, scientists have studied natural communities by taking the “evolution as stage, ecology as play” approach. Simply put, interactions between species and their environment allow natural selection to mould individuals, thus imposing a gradual change on the performance of a species. Generation after generation, species will either evolve to become increasingly more adapted to their environment, or they will become extinct.

Many types of species–environment or species–species interactions make up the ecological drivers for evolution. Some of the most important include competition for resources, predation, parasitism, mutualism and facilitation. We can now use Darwin’s theory of natural selection to infer how the interactions of a...

The full text of this article can be purchased from Informit.