Extinction and the Loss of Evolutionary History

Abstract

The loss of microbial evolutionary history is an issue that should engage the attention of microbiologists and the biotechnology community. Conservation of the microbiota can be celebrated on numerous grounds including conserving biodiversity as a matter of principle, as an underpinning element of ecosystem functioning and homeostasis at local and global scales. This chapter briefly reviews the condition of macroorganisms and attempts some prudent extrapolations from the available information. The biological extinction has occurred in the past is beyond dispute and is well documented; its causes are both natural (catastrophic events such as volcanic eruptions and asteroid strikes and by natural selection) and anthropogenic in character. After each mass extinction, biodiversity has recovered, albeit over very long periods of time—nearly 90 My for the Mesozoic fauna to recover to the degree of Palaeozoic era diversity following the Permian mass extinction; ipso facto, major losses of biodiversity are unlikely to be recovered within the time intervals subject to human attention, and extinct biota represent permanent losses. Two other points warrant our attention in this chapter: (i) is extinction random or nonrandom, and (ii) what is the state of habitat destruction?.