Chapter 10 – Environment

TL;DR: Environmental change is the major driver of evolutionary change, and even the amount and kinds of DNA present in the environment can have profound evolutionary effects when certain horizontal gene transfers occur, which they do regularly.

Abstract: Environmental change is the major driver of evolutionary change Where environments are stable for long periods of time, the trend is for species to adapt to those environments quickly and early on, and then remain relatively unchanged (stasis) for most of the longer period of stability Evolution is not an innate progression apart from environment as Lamarck believed Rather, it is change that is most often due to natural selection adapting organisms to environmental changes Environmental changes often create opportunities for some organisms, while eliminating opportunities for others Opportunities allow adaptation to move some species into different niches and ways of living, which usually involve some noticeable evolutionary changes Environments are very complex, with many biotic and abiotic components, any one of which may change over time Also, environments are ever-present and therefore always exerting some form of selection on the species, whether stabilizing or directional In the world of microbes, even the amount and kinds of DNA present in the environment can have profound evolutionary effects when certain horizontal gene transfers occur, which they do regularly The diversity of biodiversity is in large part linked with environmental diversity and change over the history of our planet