Despite their close links, ecology and evolution have remained separate
disciplines to this day. Breaking down the wall between the two
disciplines is essential for at least two reasons. First, this wall is
an obstacle to the study of most microorganisms, which constitute a
large part of the Earth's biodiversity. Asexual reproduction, gene
transfer and the lack of a clear definition of the species taxonomic
level blur the distinction between ecological changes in species
abundances and evolutionary changes in genotype frequencies in microbes.
Second, a key question that biodiversity science will have to address in
the coming decades is how ecological systems will cope with rapid
environmental change. Generalising the concept of adaptation across
multiple timescales and levels of organisation would provide an
integrative framework for studying the combined ecological and
evolutionary responses to environmental change, and thus help us to
address one the major scientific challenges of our time.