The Boundless Potential of Evolutionary Entanglements

Abstract

Abstract The previous chapter has set the stage for a discussion of Michael McDonald’s experiments on populations of single-celled yeast. He has shown that these populations quickly accumulate genetic variation even when grown in a simple environment. The yeast populations retain the most advantageous combinations of these new mutant genes and tend to lose lineages that carry disadvantageous ones. “Super-advantageous” mutations appear to be common in these populations. McDonald and others are also exploring a newly discovered part of the story of how ecosystems evolve and adapt, by studying the role of transfers of genes between hosts and parasites in simple laboratory communities. These exchanges can greatly increase the speed with which laboratory populations evolve. The chapter closes with an account of the substantial role that has been played by gene transfers between species in our own microbiomes.