Prions are often considered as anomalous proteins associated primarily with disease rather than as a fundamental source of diversity within biological proteomes. Whereas this longstanding viewpoint has its genesis in the discovery of the original namesake prions as causative agents of several complex diseases, the underlying assumption of a strict disease basis for prions could not be further from the truth. Prions and the spectrum of functions they comprise, likely represent one of the largest paradigm shifts concerning molecular-encoded phenotypic diversity since identification of DNA as the principle molecule of heredity. The ability of prions to recruit similar proteins to alternate conformations may engender a reservoir of diversity supplementing the genetic diversity resulting from stochastic mutations of DNA and subsequent natural selection. Here we present several currently known prions and how many of their functions as well as modes of transmission are intricately linked to adaptation from an evolutionary perspective. Further, the stability of some prion conformations across generations indicates that heritable prion-based adaptation is a reality.

朊病毒通常被认为是主要与疾病相关的异常蛋白质，而不是生物蛋白质组中多样性的基本来源。尽管这种长期存在的观点起源于发现原始同名朊病毒是几种复杂疾病的病原体，但朊病毒具有严格的疾病基础的基本假设与事实相去甚远。朊病毒及其包含的功能谱，可能代表了自将 DNA 确定为遗传的主要分子以来，关于分子编码表型多样性的最大范式转变之一。朊病毒招募相似蛋白质以改变构象的能力可能会产生一个多样性库，以补充由 DNA 随机突变和随后的自然选择产生的遗传多样性。在这里，我们展示了几种目前已知的朊病毒，以及它们的多少功能以及传播模式从进化的角度与适应有着错综复杂的联系。此外，跨代某些朊病毒构象的稳定性表明可遗传的基于朊病毒的适应是现实。